Home » Public Forums » GMCnet » [GMCnet] Identify electric device
| [GMCnet] Identify electric device [message #327341] |
Wed, 20 December 2017 11:50  |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
My chassis and house battery are utilized at the same time for house
stuff. Not nice.
Anyone care to tell me what the device is that red arrow points at?
https://tinyurl.com/y7sry8q6
Up where the blue arrow is, I have the isolator.
Thanks.
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327342 is a reply to message #327341] |
Wed, 20 December 2017 12:07  |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
Peer Oliver Schmidt GMC schrieb/wrote
> My chassis and house battery are utilized at the same time for house
> stuff. Not nice.
>
> Anyone care to tell me what the device is that red arrow points at?
>
> https://tinyurl.com/y7sry8q6
>
> Up where the blue arrow is, I have the isolator.
>
> Thanks.
Okay, a german GMC friend told me, it is the relais that is engaged when
the Battery Boost switch is pressed. Seems I have to check out why it
currently does not do its job of NOT combining the two.
Oh, and on a side note: Is it true, that all GMC MotorHomes were
originally equipped with an isolator?
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327347 is a reply to message #327341] |
Wed, 20 December 2017 13:32 |
NextGenGMC
Messages: 146
Registered: December 2017
Location: Washington State
Karma: -1
|
Senior Member |
|
|
That is a booster solenoid. You should have your Main Starter battery going to one side of it (I believe it is right side) and the Auxiliary or House Battery going to the other side (left). When you press AUX BATT switch on the dash, this solenoid connects both batteries for a short time and gives you a boost for starter.
It is possible that your batteries are not connected to it correctly or that the booster solenoid is stuck "ON" all the time, thus draining the starter battery together with the house batteries.
Peer Oliver Schmidt wrote on Wed, 20 December 2017 09:50My chassis and house battery are utilized at the same time for house
stuff. Not nice.
Anyone care to tell me what the device is that red arrow points at?
https://tinyurl.com/y7sry8q6
Up where the blue arrow is, I have the isolator.
Thanks.
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Vadim Jitkov
'76 Glenbrook 26'
Pullman, WA
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327348 is a reply to message #327345] |
Wed, 20 December 2017 13:42 |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
The relay does click clack when the switch changes position. Unfortunately both settings cause continuity between house and chassis. Tomorrow I shall investigate some more
--
Best regards
Peer Oliver Schmidt
'76a Eleganza II, VA
'73 Sequoia, Germany
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327349 is a reply to message #327348] |
Wed, 20 December 2017 14:51 |
tphipps
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
|
Senior Member |
|
|
Time to replace the boost solenoid. Cheap and easy.
I think all GMC's (dangerous to assume) came with an idolater to separate the house and engine batteries. Idolater is basically two diodes encased in the metal heat shield that is the outside box with fins. The diodes are electrically isolated from the case.
Tom
2012 Phoenix Cruiser model 2552
KA4CSG
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327351 is a reply to message #327341] |
Wed, 20 December 2017 14:54 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
|
|
Looks like an isolator. If it is bypassed, it may because it does not work.
There should be three terminals on the front of it.
The isolator uses a diode from the center terminal to each outer terminal
to all current from the center to the outer terminals, but not from the
outer terminals to anywhere else. The center terminal is wired directly to
the alternator output, and each outer terminal goes to a battery bank.
Rick "preferring a combiner if it has to be replaced anyway" Denney
On Wed, Dec 20, 2017 at 12:51 PM Peer Oliver Schmidt GMC <
posde@theinternet.de> wrote:
> My chassis and house battery are utilized at the same time for house
> stuff. Not nice.
>
> Anyone care to tell me what the device is that red arrow points at?
>
> https://tinyurl.com/y7sry8q6
>
> Up where the blue arrow is, I have the isolator.
>
> Thanks.
> --
> Best regards
>
> Peer Oliver Schmidt
> PGP Key ID: 0x83E1C2EA
>
> '76a Eleganza II 26', VA
> '73 Sequoia 23', Germany, SH
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327352 is a reply to message #327341] |
Wed, 20 December 2017 14:56 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
|
Senior Member |
|
|
Never mind--I misread the original post.
Rick "NOT what the blue arrow is pointing to" Denney
On Wed, Dec 20, 2017 at 3:54 PM Richard Denney wrote:
> Looks like an isolator. If it is bypassed, it may because it does not
> work. There should be three terminals on the front of it.
>
> The isolator uses a diode from the center terminal to each outer terminal
> to all current from the center to the outer terminals, but not from the
> outer terminals to anywhere else. The center terminal is wired directly to
> the alternator output, and each outer terminal goes to a battery bank.
>
> Rick "preferring a combiner if it has to be replaced anyway" Denney
>
> On Wed, Dec 20, 2017 at 12:51 PM Peer Oliver Schmidt GMC posde@theinternet.de> wrote:
>
>> My chassis and house battery are utilized at the same time for house
>> stuff. Not nice.
>>
>> Anyone care to tell me what the device is that red arrow points at?
>>
>> https://tinyurl.com/y7sry8q6
>>
>> Up where the blue arrow is, I have the isolator.
>>
>> Thanks.
>> --
>> Best regards
>>
>> Peer Oliver Schmidt
>> PGP Key ID: 0x83E1C2EA
>>
>> '76a Eleganza II 26', VA
>> '73 Sequoia 23', Germany, SH
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> --
> Rick Denney
> 73 x-Glacier 230 "Jaws"
> Off-list email to rick at rickdenney dot com
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327353 is a reply to message #327351] |
Wed, 20 December 2017 15:01 |
k2gkk
Messages: 4452
Registered: November 2009
Karma: -8
|
Senior Member |
|
|
Isn't what the red arrow points at the "boost" relay to parallel both batteries when the boost switch is engaged to allow the house battery to be used to start the engine?
D C "Mac" Macdonald
Amateur Radio K2GKK
Since 30 November '53
USAF and FAA, Retired
Member GMCMI & Classics
Oklahoma City, OK
"The Money Pit"
TZE166V101966
'76 ex-Palm Beach
k2gkk + hotmail dot com
________________________________
From: Gmclist on behalf of Richard Denney
Sent: Wednesday, December 20, 2017 14:54
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Identify electric device
Looks like an isolator. If it is bypassed, it may because it does not work.
There should be three terminals on the front of it.
The isolator uses a diode from the center terminal to each outer terminal
to all current from the center to the outer terminals, but not from the
outer terminals to anywhere else. The center terminal is wired directly to
the alternator output, and each outer terminal goes to a battery bank.
Rick "preferring a combiner if it has to be replaced anyway" Denney
On Wed, Dec 20, 2017 at 12:51 PM Peer Oliver Schmidt GMC <
posde@theinternet.de> wrote:
> My chassis and house battery are utilized at the same time for house
> stuff. Not nice.
>
> Anyone care to tell me what the device is that red arrow points at?
>
> https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftinyurl.com%2Fy7sry8q6&data=02%7C01%7C%7Ced6bf358166544acb17408d547ec0aec%7C84df 9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636494001467870804&sdata=clSgl6lw7aX327ZWPvUeZ2ZJ9QQgkOkgpSUkxUPtVj8%3D&reserved=0
>
> Up where the blue arrow is, I have the isolator.
>
> Thanks.
> --
> Best regards
>
> Peer Oliver Schmidt
> PGP Key ID: 0x83E1C2EA
>
> '76a Eleganza II 26', VA
> '73 Sequoia 23', Germany, SH
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Flist.gmcnet.org%2Fmailman%2Flistinfo%2Fgmclist_list.gmcnet.org&data=02%7C01%7C%7C ed6bf358166544acb17408d547ec0aec%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636494001467870804&sdata=SG6gOxF%2F2m%2BCw8cPrEwHHGnqoFTZ%2BvRX5FO%2 B3s6x3TM%3D&reserved=0
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Flist.gmcnet.org%2Fmailman%2Flistinfo%2Fgmclist_list.gmcnet.org&data=02%7C01%7C%7C ed6bf358166544acb17408d547ec0aec%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636494001467870804&sdata=SG6gOxF%2F2m%2BCw8cPrEwHHGnqoFTZ%2BvRX5FO%2 B3s6x3TM%3D&reserved=0
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327355 is a reply to message #327349] |
Wed, 20 December 2017 15:44 |
NextGenGMC
Messages: 146
Registered: December 2017
Location: Washington State
Karma: -1
|
Senior Member |
|
|
That is a separate part. It is intended to allow both banks of batteries to be charged when the engine was running, but not to allow battery with higher voltage to attempt to charge the other one that is depleted.
tphipps wrote on Wed, 20 December 2017 12:51Time to replace the boost solenoid. Cheap and easy.
I think all GMC's (dangerous to assume) came with an idolater to separate the house and engine batteries. Idolater is basically two diodes encased in the metal heat shield that is the outside box with fins. The diodes are electrically isolated from the case.
Tom
Vadim Jitkov
'76 Glenbrook 26'
Pullman, WA
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327366 is a reply to message #327342] |
Wed, 20 December 2017 19:40 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Peer Oliver Schmidt wrote on Wed, 20 December 2017 13:07Okay, a german GMC friend told me, it is the relais that is engaged when
the Battery Boost switch is pressed. Seems I have to check out why it currently does not do its job of NOT combining the two.
Oh, and on a side note: Is it true, that all GMC MotorHomes were originally equipped with an isolator?
--
Best regards
Peer Oliver Schmidt
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
Peer,
Answer for the first part you have been given. But as a practical matter, if you can't hear the boost contactor (what a BIG relay is often called) make a THUNK when you it the switch, it is not working.
There are three possibilities:
1 - It is not getting the 12V signal to close.
2 - It is getting the 12V signal, but the winding is bad. Do not replace it with a starter type contactor as they are not continues duty and this application should be. These are also used for things that draw power for a long time like emergency light on ambulances.
3 - The device contacts have welded. This makes it always On". It is not a common failure, but I have seen them.
To answer your side question. By my experience (not limited to GMCs as motorhomes), Yes, All were shipped with an isolator and a boost contactor.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327368 is a reply to message #327341] |
Wed, 20 December 2017 19:59 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
I would like to point out that the "Boost relay" is next to never used in normal operation
of your coach. It is only operational when the boost switch on the dash is energized by
the driver. In some years the switch is momentary and in earlier years the switch could be
left in the on position.
How you you know that the boost relay is conducting? If you are doing voltage checks
rather than disconnecting it from the circuit and checking it with an ohm meter, the
problem could easily be located somewhere else in the coach and you are just reading it
there.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327378 is a reply to message #327368] |
Thu, 21 December 2017 03:14 |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
An update:
The solenoid does click whenever the switch on the dash changes position.
And, after unscrewing the cables from the left hand side of the solenoid
(which are part of the house battery), the house lights still works. So,
I somewhere have a nice little present from a previous owner, where the
house circuit is given energy from the chassis battery. Aint this nice.
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327379 is a reply to message #327378] |
Thu, 21 December 2017 03:48 |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
And another update:
Unscrewing the house part from the isolator causes all lights in the
house to stop functioning - Yeahy, it is just a shot isolator, and not
some PO screwage. Sorry for even mentioning that one of the gazillion
POs of my 23' might have caused this. :-)
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327383 is a reply to message #327381] |
Thu, 21 December 2017 09:22 |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
Dave Stragand schrieb/wrote
> Can you post a photo or two of the wiring around the isolator and solenoid at gmcmhphotos.com? We might be able to spot an incorrect wire position or jumper.
Afaict the wiring is correct https://photos.app.goo.gl/RH9ts3TZrzy0L8f02
- the solenoid's wiring can be looked at in more detail at the original
tinyurl I posted at the beginning of the thread.
The minute I remote the house wire from the isolator, all lights go off.
The new device is only ~50EUR and will replace the solenoid and the
insulator, so it is a helpful thing anyway.
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327386 is a reply to message #327383] |
Thu, 21 December 2017 12:28 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
I question your diagnosis in that to have a failure that you are describing,
it would take a double shorted diode in the isolator and no power being supplied by the house battery
Removing the isolator from the circuit should NOT interrupt the power coming from the house battery.
The isolator is part of the alternator power supply circuit and has nothing to do with the battery
supplying power to the coach.
I think that you have a wiring error and not an isolator problem. It sounds like your house battery
is supplying power to the center terminal of the isolator rather than direct to the house circuits.
I also would be careful removing the boost relay. It will be very possible to over current that new
combiner by trying to start the engine using the boost function.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327390 is a reply to message #327383] |
Thu, 21 December 2017 15:11 |
|
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Peer,
This is not any kind of a criticism of of your language capability. (Your English is much better than my German.)
The blue finned thing is the isolator and the round thing below it is the boost solenoid. Agree?
(Remember I have another '73 23' and know the issues well.)
Are you saying the the house lights stay on when you remove the cables to the outboard side of the boost solenoid, but go out when you remove the wire from the house terminal of the isolator?
Ken wrote: I question your diagnosis in that to have a failure that you are describing, it would take a double shorted diode in the isolator and no power being supplied by the house battery.
I have been straining to get this figured out and Ken may be mistaken.... (I never thought I would write that. - Either Ken)
If the alternator to engine battery went solid (as opposed to open) then this could happen, but it would require some creative rewiring as the terminal that is the central to all the 12V house is that post in the boost contactor. This would also make the alternator terminal hot when it should not be, but that should cause no other issues.
If the both diodes solid is correct, that is a very strange case. In all my years of 12V electrics, I have only seen one isolator diode go solid. These typically fail open when they do fail and that is just not common. And the rarely both fail. (Lightning strikes are another matter.)
I have to believe that that there is something there that should not be.
A simple test with a meter will confirm that the isolator has failed. An ohmmeter reading from the center to either post should give a reading one way and nothing the other.
Please tell us if/when you find it.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: [GMCnet] Identify electric device [message #327392 is a reply to message #327390] |
Thu, 21 December 2017 16:12 |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
|
Senior Member |
|
|
Let me try to clear things up:
When I take the house battery out of the coach, the lights of the house
still work. Removing the house battery cable from the boost solenoid did
not turn off the house lights. Removing the house battery cable from the
isolator caused the lights to go off.
This means to me, that the house battery circuit is receiving energy
through the isolator from the chassis battery, something that should not
happen.
Feel free to correct me if I am wrong :-)
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II 26', VA
'73 Sequoia 23', Germany, SH
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
|
|
|
|
Goto Forum:
Current Time: Fri Apr 26 14:22:09 CDT 2024
Total time taken to generate the page: 0.01211 seconds
|
GMCforum
Search
Help
Register
Login
Home
