| [GMCnet] electrical problem [message #107675] |
Mon, 06 December 2010 11:52  |
Charles
Messages: 455
Registered: January 2004
Karma: 0
|
Senior Member |
|
|
Recently my 1975,GMC did not crank when I tried to start it with the engine
battery.
I used the dash jump switch and it cranked and started. I then turned the
dash jump
switch off and drove the coach home. Yesterday, almost a month later, I
pulled
the engine battery and took it to Autozone and had it checked. It was good
and
showed 13.2 volts. I have a Yolinda combiner on this coach and when I got
home from the trip where the coach didn’t start I plugged into house voltage
which
I think would have charged both the engine and the house batteries. While
removing the engine battery I bumped the positive cable to ground and got a
big spark. The cable was completely disconnected from the engine battery
when
this happened. I thought it should not have had any voltage in it. The dash
switch
was off so the solenoid should have been open but it appears voltage was
coming
through it to the engine positive cable from the coach battery.. I removed
the engine positive
cable from the solenoid and checked the solenoid with an ohm meter. It
showed 100%
continuity across the legs of the solenoid. I then disconnected the solenoid
activation wire
from the solenoid thinking there might be a problem with the dash switch and
this
would eliminate it from the system. Things changed but not completely. Now
when
I check the solenoid for continuity across what should be an open circuit I
get a blip
of continuity but not 100% . Could the Yolinda combiner causing these
reading and
line connection? Does it sound like a bad solenoid. I have a life time
warranty on
it so it would not take much to replace it. I have more than half the wires
off of it
already. Any help and suggestions would be appreciated.
Charles
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Charles Wersal
Duncanville, Texas
26 foot 1975 Glenbrook
Pandora's Box
|
|
|
|
| Re: [GMCnet] electrical problem [message #107680 is a reply to message #107675] |
Mon, 06 December 2010 12:18  |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Charles,
Unless I'm missing something, everything was operating properly up to the
time you grounded the positive lead -- and may still be.
When you disconnected the chassis battery, if 120 vac was available to the
converter, it should have been charging the engine battery through the
Yandina combiner. Even after you removed the battery connection, the
combiner was still closed -- making the disconnected positive lead hot. I
don't think the combiner detects the absence of a battery at all, but even
if it does, there's a 30 second delay before it reacts.
Since the combiner has the long protective leads (if you didn't cut them
off), the current from the short should not have destroyed the combiner. If
you hook everything back up, I'll bet it will work OK. Except perhaps for
the past starting problem -- have you done anything to fix that? Or were
the lights left on, killing the chassis battery? :-)
REMEMBER: If you're going to remove the positive battery leads for any
reason, make sure there's no spurious source of voltage for it -- disconnect
the 120 vac too.
Ken H.
On Mon, Dec 6, 2010 at 12:52 PM, Charles <gcw13@sbcglobal.net> wrote:
> ...showed 13.2 volts. I have a Yolinda combiner on this coach and when I
> got
>
> home from the trip where the coach didn’t start I plugged into house
> voltage
> which
>
> I think would have charged both the engine and the house batteries. While
>
> removing the engine battery I bumped the positive cable to ground and got a
>
> big spark. The cable was completely disconnected from the engine battery
> when
>
> this happened. I thought it should not have had any voltage in it. The dash
> switch
>
> was off so the solenoid should have been open but it appears voltage was
> coming
>
> through it to the engine positive cable from the coach battery.. I removed
> the engine positive
>
> cable from the solenoid and checked the solenoid with an ohm meter. It
> showed 100%
>
> continuity across the legs of the solenoid. I then disconnected the
> solenoid
> activation wire
>
> from the solenoid thinking there might be a problem with the dash switch
> and
> this
>
> would eliminate it from the system. Things changed but not completely. Now
> when
>
> I check the solenoid for continuity across what should be an open circuit I
> get a blip
>
> of continuity but not 100% . Could the Yolinda combiner causing these
> reading and
>
> line connection? Does it sound like a bad solenoid. I have a life time
> warranty on
>
> it so it would not take much to replace it. I have more than half the wires
> off of it
>
> already. Any help and suggestions would be appreciated.
>
> Charles
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] electrical problem [message #107696 is a reply to message #107680] |
Mon, 06 December 2010 16:26 |
 |
mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
|
Senior Member |
|
|
| Ken Henderson wrote on Mon, 06 December 2010 10:18 |
... I don't think the combiner detects the absence of a battery at all,
but even if it does, there's a 30 second delay before it reacts. ...
|
I _KNOW_ the combiner doesn't care if there is a battery on both sides or not. One application of a combiner is to provide 12 volt power to something only when the battery is receiving a charging voltage. (Like a 12v refrigerator on a power boat.)
You can look at the little LED on the combiner to see if it is combined. I have seen them stay combined for 4 or 5 minutes after all the charging sources were removed. (Batteries equalizing and the like.)
Yes, with RV/boat "multi-battery" systems, be sure and remove _ALL_ sources of power when connecting/disconnecting any of the batteries. Then still treat the cables as if they have power. -- I hate surprises with power systems.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
|
|
|
|
|
|
| Re: [GMCnet] electrical problem [message #107720 is a reply to message #107715] |
Mon, 06 December 2010 19:51 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
| Hardie Johnson wrote on Mon, 06 December 2010 19:40 |
| mike miller wrote on Mon, 06 December 2010 17:26 |
| Ken Henderson wrote on Mon, 06 December 2010 10:18 |
... I don't think the combiner detects the absence of a battery at all, but even if it does, there's a 30 second delay before it reacts. ...
|
I _KNOW_ the combiner doesn't care if there is a battery on both sides or not. One application of a combiner is to provide 12 volt power to something only when the battery is receiving a charging voltage. (Like a 12v refrigerator on a power boat.)
<>
|
I was thinking we are supposed to disconnect the Negative side first? Yes, No, Maybe??
"I am not called Sparky"
|
It does not hurt which one you disconnect first.
BUT... for safety purposes people disconnect negative first just in case the wrench they are using should touch the frame or something grounded. If you do the positive side first and drag a wrench between it and something grounded, like the battery hold down, you have one heck of an short term arc welder in your hands.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
|
|
|
|
|
|
|
|
| Re: [GMCnet] Electrical problem [message #146591 is a reply to message #146580] |
Sat, 15 October 2011 09:31 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
| Mr ERFisher wrote on Sat, 15 October 2011 09:25 |
The combiner will correct for most isolator problems , they fail open, and I am sure the with the alternator wire connected to the engine battery wire, would be a good indicator that the isolator was not in the circuit.
I am willing to bet , the isolator is not shorted.... maybe we will find out
jwid
gene
> The other problem with this is that you don't really know the mode of failure inside the isolator and some failures can be intermittent or the disconnect gap so small that a future connection between terminals could occur. Probably not a high probability but not zero. This may only create frustrating debug problems or catastrophic problems depending on what the terminals were used for.
>
> Dan Winchester
but leaving an old isolator in place and using it as a terminal block for other wiring is not a good idea. It would be difficult to label it well enough to not cause confusion to future owner or mechanic.
--
Gene Fisher
|
As I said in a prior note, isolator failures are not at all uncommon. It seems they are most common after an alternator upgrade (very common for cruising sailors).
What is very uncommon is to have a diode fail shorted. I have seen this, but it is very rare. Even in the case that a failed diode should happen to reform a connection (never seen this), at most it would be a high resistance to only the now unused alternator terminal as that part has no other connection.
Another problem is that barrier strips or terminal boards with 1/4-28 screws are rather difficult to come by. As the 100amp Yandina has only wire leads that should not be cut, a set of hard mounted terminals is required.
So, when someone comes across an isolator with no connection on the alternator terminal he should suspect something is not as it was originally. The Xs carved in the epoxy or painted on with fingernail polish is another big give-away.
In marine service, if the isolator failed so hard that it cracked the epoxy, I would require is replacement or a installation of a hard mounted terminal set.
I did see one fail so hard that a connection was formed to the heat sink. The heat sink was grounded (like out coaches - unusual on a boat). That one did blow out the epoxy. The owner had tried to swap the engine for the house battery in the middle of a night race and got it backwards. The isolator was the least expensive part that needed replacement.
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] Electrical problem [message #146602 is a reply to message #146574] |
Sat, 15 October 2011 10:35 |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
|
Senior Member |
|
|
On Oct 15, 2011, at 6:39 AM, Dan Winchester wrote:
> I will speak out of two sides of my mouth here as my coach is a rats nest of wiring and is not a good example, but leaving an old isolator in place and using it as a terminal block for other wiring is not a good idea. It would be difficult to label it well enough to not cause confusion to future owner or mechanic.
>
> The other problem with this is that you don't really know the mode of failure inside the isolator and some failures can be intermittent or the disconnect gap so small that a future connection between terminals could occur. Probably not a high probability but not zero. This may only create frustrating debug problems or catastrophic problems depending on what the terminals were used for.
>
> Dan Winchester
> www.dwinchester.com
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Emery Stora
77 Kingsley
Santa Fe, NM
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
