Home » Public Forums » GMCnet » [GMCnet] Trailer wiring "blue wire"
| [GMCnet] Trailer wiring "blue wire" [message #179042] |
Sun, 05 August 2012 00:00  |
Dolph Santorine
Messages: 1236
Registered: April 2011
Location: Wheeling, WV
Karma: -41
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Senior Member |
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Hi all
My coach has the factory blue wire for trailer brakes.
Where can I find it in the front of the coach?
I see it referenced in a number of threads but no location is mentioned.
Thanks
Dolph Santorine
Dolph@DolphSantorine.com
Excuse me for not being my usual wordy and sporadically verbose self. This message is sent from my iPhone.
No trees were killed in the sending of this message and few long dead dinosaurs were involved. A large number of electrons were terribly inconvenienced.
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| Re: [GMCnet] Trailer wiring "blue wire" [message #179054 is a reply to message #179042] |
Sun, 05 August 2012 07:37  |
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The blue wire is to power electric brakes on the trailer, if present. I don't know where the source of the blue wire is but it may be tied into the wiring that activates the brake lights at the rear.
Bill Brown - '77 Buckeye Cruiser
Coshocton OH
carguybill@sbcglobal.net
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| Re: [GMCnet] Trailer wiring "blue wire" [message #179061 is a reply to message #179058] |
Sun, 05 August 2012 09:41 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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I installed my electric brake controller before I was active in this group. I saw that there was a 'blue wire' in the wiring harness, but I couldn't find it at the front either, so I ran another one from the brake controller to the back. It seemed easier to me although, obviously, not as clean. I ran it under the coach and tied it to the gas lines. It has worked well for four years. If I ever have to redo this, I will attempt to utilize the provided wire.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180308 is a reply to message #180306] |
Tue, 14 August 2012 22:59 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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JR, ALWAYS establish a good ground between the two vehicles before you do
anything else. That is the source of more problems with trailer connections
than anything I can think of. They will back feed and cross feed if you
don't have a good ground.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Tue, Aug 14, 2012 at 8:44 PM, Gerald Wheeler <jrwheeler7@earthlink.net>wrote:
>
> Speaking of blue wires, I have the blues as I am having problems with my
> daughter's coach towing wiring. I have tested my daughter's towd wiring
> system with my coach and all lights work correctly (brakes, turn signals,
> etc). But plugged into her coach, a number of things happen. With the
> coach lights off, both turn signals work and the proper filaments light up.
> But the other bulb filament lights when the brakes are applied (should be
> same filament). With the coach lights on, the turn signal lights the
> wrong filament (not the same filament when the coach lights are off) and
> the other towd light flashes too. I won't list the other combinations
> that don't work properly. What I need to know is where I should tap into
> the coach wiring system to run all NEW wires for the towing lights?? Would
> also like to know where to hook a blue wire for trailer brakes. All
> suggestions are appreciated.
>
> JR Wheeler NC/OR
>
>
>
> > [Original Message]
> > From: Bill Brown <carguybill@sbcglobal.net>
> > To: <gmclist@temp.gmcnet.org>
> > Date: 8/5/2012 5:37:37 AM
> > Subject: Re: [GMCnet] Trailer wiring "blue wire"
> >
> >
> >
> > The blue wire is to power electric brakes on the trailer, if present. I
> don't know where the source of the blue wire is but it may be tied into the
> wiring that activates the brake lights at the rear.
> > --
> > Bill Brown - '77 Buckeye Cruiser
> > Coshocton OH
> > carguybill@sbcglobal.net
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2197 / Virus Database: 2437/5178 - Release Date: 08/04/12
>
>
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180309 is a reply to message #180308] |
Tue, 14 August 2012 23:26 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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Senior Member |
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| Quote: |
JR, ALWAYS establish a good ground between the two vehicles before you do
anything else. That is the source of more problems with trailer connections
than anything I can think of. They will back feed and cross feed if you
don't have a good ground.
Jim Hupy
Salem, OR
78 GMC Royale 403
|
Jim I concur. It's a ground problem.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180310 is a reply to message #180306] |
Tue, 14 August 2012 23:49 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
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Senior Member |
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when in doubt go to u haul and give them 20 bucks for wiring.
i also get these bulbs from uhaul that two wires hang out side the lens from the bulbs you buy and then you
just plug into the bulbs if you know what i mean. they sell them there. piggy back bulbs and connections.
sort of an emergency design only but i put one in 10 years ago for a boat and never changed them.
mick
77 palm beach
disneyland ca.
On Aug 14, 2012, at 8:44 PM, Gerald Wheeler wrote:
>
> Speaking of blue wires, I have the blues as I am having problems with my
> daughter's coach towing wiring. I have tested my daughter's towd wiring
> system with my coach and all lights work correctly (brakes, turn signals,
> etc). But plugged into her coach, a number of things happen. With the
> coach lights off, both turn signals work and the proper filaments light up.
> But the other bulb filament lights when the brakes are applied (should be
> same filament). With the coach lights on, the turn signal lights the
> wrong filament (not the same filament when the coach lights are off) and
> the other towd light flashes too. I won't list the other combinations
> that don't work properly. What I need to know is where I should tap into
> the coach wiring system to run all NEW wires for the towing lights?? Would
> also like to know where to hook a blue wire for trailer brakes. All
> suggestions are appreciated.
>
> JR Wheeler NC/OR
>
>
>
>> [Original Message]
>> From: Bill Brown <carguybill@sbcglobal.net>
>> To: <gmclist@temp.gmcnet.org>
>> Date: 8/5/2012 5:37:37 AM
>> Subject: Re: [GMCnet] Trailer wiring "blue wire"
>>
>>
>>
>> The blue wire is to power electric brakes on the trailer, if present. I
> don't know where the source of the blue wire is but it may be tied into the
> wiring that activates the brake lights at the rear.
>> --
>> Bill Brown - '77 Buckeye Cruiser
>> Coshocton OH
>> carguybill@sbcglobal.net
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 2012.0.2197 / Virus Database: 2437/5178 - Release Date: 08/04/12
>
>
> _______________________________________________
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180320 is a reply to message #179042] |
Wed, 15 August 2012 00:24 |
Gerald Wheeler
Messages: 152
Registered: February 2004
Karma: 0
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Senior Member |
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This coach had some wires hanging near the bumper, all taped up, which I
assumed was for towd/trailer. I unwrapped them and tested each wire
individually for all functions, identifying which wire did what with a
single test bulb. I had purchased many years ago a standard towd/trailer
magnetic running light set; 30' of wire, 6 pin connector with four wires:
white ground, green rt turn, yellow left turn, brown running lights. I
took the plug apart to make sure they were wired in the correct positions.
I installed Merrill's thru the bumper hitch and installed a 6 pin connector
using the wires I identified thru testing on the coach. I wired the coach
connector correctly to mate with the towd/trailer connector. Since the
towd/trailer system tested properly with my coach, the problem has to be
with the wiring in my daughter's coach. I actually used two different
ground wires. I'll remove the coach ground wire (as determined by my
testing) and use only the ground wire I put in. Perhaps that coach
ground wire is doing something funny. I'll report back tomorrow. The
GMC guru Gene Fisher along with Gary Bovee are dropping by tomorrow, so
maybe they will have some ideas. Report around 3pm PST.
JR Wheeler NC/OR
> [Original Message]
> From: James Hupy <jamesh1296@gmail.com>
> To: <gmclist@temp.gmcnet.org>
> Date: 8/14/2012 8:59:22 PM
> Subject: Re: [GMCnet] Trailer wiring "blue wire"
>
> JR, ALWAYS establish a good ground between the two vehicles before you do
> anything else. That is the source of more problems with trailer
connections
> than anything I can think of. They will back feed and cross feed if you
> don't have a good ground.
> Jim Hupy
> Salem, OR
> 78 GMC Royale 403
>
> On Tue, Aug 14, 2012 at 8:44 PM, Gerald Wheeler
<jrwheeler7@earthlink.net>wrote:
>
> >
> > Speaking of blue wires, I have the blues as I am having problems with my
> > daughter's coach towing wiring. I have tested my daughter's towd
wiring
> > system with my coach and all lights work correctly (brakes, turn
signals,
> > etc). But plugged into her coach, a number of things happen. With the
> > coach lights off, both turn signals work and the proper filaments light
up.
> > But the other bulb filament lights when the brakes are applied (should
be
> > same filament). With the coach lights on, the turn signal lights the
> > wrong filament (not the same filament when the coach lights are off) and
> > the other towd light flashes too. I won't list the other combinations
> > that don't work properly. What I need to know is where I should tap
into
> > the coach wiring system to run all NEW wires for the towing lights??
Would
> > also like to know where to hook a blue wire for trailer brakes. All
> > suggestions are appreciated.
> >
> > JR Wheeler NC/OR
> >
> >
> >
> > > [Original Message]
> > > From: Bill Brown <carguybill@sbcglobal.net>
> > > To: <gmclist@temp.gmcnet.org>
> > > Date: 8/5/2012 5:37:37 AM
> > > Subject: Re: [GMCnet] Trailer wiring "blue wire"
> > >
> > >
> > >
> > > The blue wire is to power electric brakes on the trailer, if present.
I
> > don't know where the source of the blue wire is but it may be tied into
the
> > wiring that activates the brake lights at the rear.
> > > --
> > > Bill Brown - '77 Buckeye Cruiser
> > > Coshocton OH
> > > carguybill@sbcglobal.net
> > > _______________________________________________
> > > GMCnet mailing list
> > > Unsubscribe or Change List Options:
> > > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> > >
> > >
> > > -----
> > > No virus found in this message.
> > > Checked by AVG - www.avg.com
> > > Version: 2012.0.2197 / Virus Database: 2437/5178 - Release Date:
08/04/12
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.2197 / Virus Database: 2437/5201 - Release Date: 08/14/12
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180322 is a reply to message #180309] |
Wed, 15 August 2012 00:36 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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| John Sharpe wrote on Tue, 14 August 2012 23:26 |
| Quote: |
JR, ALWAYS establish a good ground between the two vehicles before you do
anything else. That is the source of more problems with trailer connections
than anything I can think of. They will back feed and cross feed if you
don't have a good ground.
Jim Hupy
Salem, OR
78 GMC Royale 403
|
Jim I concur. It's a ground problem.
|
That was my first thought also.
Grab a set of jumper cables. Connect one to the steel bumpers of the towing vehicle and the towd. If the lights work correctly then you will know that you need to correct the ground connections.
What kind of vehicle are you towing? I am assuming that the towing vehicle is a GMC.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180329 is a reply to message #180306] |
Wed, 15 August 2012 06:31 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
|
Senior Member |
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http://www.harborfreight.com/four-way-trailer-light-tester-66526.html or
http://www.tlt-tool.com/
Or, the best I have found so far are the wireless, magnetic base lights.
Pay once, easily xferable from vehicle to vehicle or to a trailer. NO
connections and they are extremely bright. I use rechargeable batteries
(Sony Eneloop are the industry leaders) and I keep a charger in the coach.
Batteries last well over 24 towing hours.
On Tue, Aug 14, 2012 at 8:44 PM, Gerald Wheeler <jrwheeler7@earthlink.net>wrote:
>
> Speaking of blue wires, I have the blues as I am having problems with my
> daughter's coach towing wiring. I have tested my daughter's towd wiring
> system with my coach and all lights work correctly (brakes, turn signals,
> etc). But plugged into her coach, a number of things happen. With the
> coach lights off, both turn signals work and the proper filaments light up.
> But the other bulb filament lights when the brakes are applied (should be
> same filament). With the coach lights on, the turn signal lights the
> wrong filament (not the same filament when the coach lights are off) and
> the other towd light flashes too. I won't list the other combinations
> that don't work properly. What I need to know is where I should tap into
> the coach wiring system to run all NEW wires for the towing lights?? Would
> also like to know where to hook a blue wire for trailer brakes. All
> suggestions are appreciated.
>
> JR Wheeler NC/OR
>
>
>
> > [Original Message]
> > From: Bill Brown <carguybill@sbcglobal.net>
> > To: <gmclist@temp.gmcnet.org>
> > Date: 8/5/2012 5:37:37 AM
> > Subject: Re: [GMCnet] Trailer wiring "blue wire"
> >
> >
> >
> > The blue wire is to power electric brakes on the trailer, if present. I
> don't know where the source of the blue wire is but it may be tied into the
> wiring that activates the brake lights at the rear.
> > --
> > Bill Brown - '77 Buckeye Cruiser
> > Coshocton OH
> > carguybill@sbcglobal.net
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2197 / Virus Database: 2437/5178 - Release Date: 08/04/12
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Fathom the hypocrisy of a nation where every citizen must prove they have
health insurance......but not everyone has to prove they're a citizen.
Steve Ferguson
Sierra Vista, AZ
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180383 is a reply to message #179042] |
Wed, 15 August 2012 14:21 |
Gerald Wheeler
Messages: 152
Registered: February 2004
Karma: 0
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Senior Member |
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I'll report back tomorrow. The
GMC guru Gene Fisher along with Gary Bovee are dropping by tomorrow, so
maybe they will have some ideas. Report around 3pm PST.
Gene Fisher and Gary Bovee came early and Gene was able to solve my
problem. It was a grounding problem as several of you suggested; but one
that I would never have thought of. I installed a new 6 pin round plug on
my daughter's coach. All wires were attached correctly to the male and
female plugs. The ground wire was connected to the frame properly. What
it turned out to be was the male pin on the new 6 pin round connector was
making intermittent contact with the female receptacle ( the sides of the
male pin didn't touch the sides of the female receptacle). Problem was
solved by spreading the ends of that male pin of the new plug. When I
tested the towd/trailer light assembly with my other coach, the plugs mated
properly and the lights worked. I would have bet good dollars that
grounding was not the problem given the number of wires the coach had
available for towd/trailer towing. Thanks again Gene Fisher.
JR Wheeler NC/OR
> [Original Message]
> From: Gerald Wheeler <jrwheeler7@earthlink.net>
> To: <gmclist@temp.gmcnet.org>
> Date: 8/14/2012 10:24:31 PM
> Subject: Re: [GMCnet] Trailer wiring "blue wire"
>
>
> This coach had some wires hanging near the bumper, all taped up, which I
> assumed was for towd/trailer. I unwrapped them and tested each wire
> individually for all functions, identifying which wire did what with a
> single test bulb. I had purchased many years ago a standard towd/trailer
> magnetic running light set; 30' of wire, 6 pin connector with four wires:
> white ground, green rt turn, yellow left turn, brown running lights. I
> took the plug apart to make sure they were wired in the correct
positions.
> I installed Merrill's thru the bumper hitch and installed a 6 pin
connector
> using the wires I identified thru testing on the coach. I wired the
coach
> connector correctly to mate with the towd/trailer connector. Since the
> towd/trailer system tested properly with my coach, the problem has to be
> with the wiring in my daughter's coach. I actually used two different
> ground wires. I'll remove the coach ground wire (as determined by my
> testing) and use only the ground wire I put in. Perhaps that coach
> ground wire is doing something funny. I'll report back tomorrow. The
> GMC guru Gene Fisher along with Gary Bovee are dropping by tomorrow, so
> maybe they will have some ideas. Report around 3pm PST.
>
> JR Wheeler NC/OR
>
>
>
> > [Original Message]
> > From: James Hupy <jamesh1296@gmail.com>
> > To: <gmclist@temp.gmcnet.org>
> > Date: 8/14/2012 8:59:22 PM
> > Subject: Re: [GMCnet] Trailer wiring "blue wire"
> >
> > JR, ALWAYS establish a good ground between the two vehicles before you
do
> > anything else. That is the source of more problems with trailer
> connections
> > than anything I can think of. They will back feed and cross feed if you
> > don't have a good ground.
> > Jim Hupy
> > Salem, OR
> > 78 GMC Royale 403
> >
> > On Tue, Aug 14, 2012 at 8:44 PM, Gerald Wheeler
> <jrwheeler7@earthlink.net>wrote:
> >
> > >
> > > Speaking of blue wires, I have the blues as I am having problems with
my
> > > daughter's coach towing wiring. I have tested my daughter's towd
> wiring
> > > system with my coach and all lights work correctly (brakes, turn
> signals,
> > > etc). But plugged into her coach, a number of things happen. With
the
> > > coach lights off, both turn signals work and the proper filaments
light
> up.
> > > But the other bulb filament lights when the brakes are applied (should
> be
> > > same filament). With the coach lights on, the turn signal lights the
> > > wrong filament (not the same filament when the coach lights are off)
and
> > > the other towd light flashes too. I won't list the other
combinations
> > > that don't work properly. What I need to know is where I should tap
> into
> > > the coach wiring system to run all NEW wires for the towing lights??
> Would
> > > also like to know where to hook a blue wire for trailer brakes. All
> > > suggestions are appreciated.
> > >
> > > JR Wheeler NC/OR
> > >
> > >
> > >
> > > > [Original Message]
> > > > From: Bill Brown <carguybill@sbcglobal.net>
> > > > To: <gmclist@temp.gmcnet.org>
> > > > Date: 8/5/2012 5:37:37 AM
> > > > Subject: Re: [GMCnet] Trailer wiring "blue wire"
> > > >
> > > >
> > > >
> > > > The blue wire is to power electric brakes on the trailer, if
present.
> I
> > > don't know where the source of the blue wire is but it may be tied
into
> the
> > > wiring that activates the brake lights at the rear.
> > > > --
> > > > Bill Brown - '77 Buckeye Cruiser
> > > > Coshocton OH
> > > > carguybill@sbcglobal.net
> > > > _______________________________________________
> > > > GMCnet mailing list
> > > > Unsubscribe or Change List Options:
> > > > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> > > >
> > > >
> > > > -----
> > > > No virus found in this message.
> > > > Checked by AVG - www.avg.com
> > > > Version: 2012.0.2197 / Virus Database: 2437/5178 - Release Date:
> 08/04/12
> > >
> > >
> > > _______________________________________________
> > > GMCnet mailing list
> > > Unsubscribe or Change List Options:
> > > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> > >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2197 / Virus Database: 2437/5201 - Release Date:
08/14/12
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.2197 / Virus Database: 2437/5201 - Release Date: 08/14/12
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| Re: [GMCnet] Trailer wiring "blue wire" [message #180436 is a reply to message #180427] |
Wed, 15 August 2012 21:06 |
midlf
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
|
Senior Member |
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| tphipps wrote on Wed, 15 August 2012 20:23 |
Can the blue wire be used to fire up a 3rd brake light? Hate to reinvent something, if it is already there.
Tom, MS I I
|
Yes - if you can find the head end of it. Some have reported this is difficult. I haven't found mine yet. I want to use it, as intended, for electric brakes.
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
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