1994 Chevy Van Ghost Electrical issue

JERRYPCMAN

MEMBER
1994 CHEVROLET VAN
V8
2WD
AUTOMATIC
130,000 MILES

Indications:
When I drive the van normally, no A/c no lights the trans shifts through the gears fine. But when I push the breaks or put the lifghts on my volt meter drops to close to 10VDC and if I put the A/c on the van will not shift oput of second gear.

Also when I put any electrical load on the van with it turned off, my gauges start to rotate around. IE the temp gauge if I keep pressing the door lacks will keep moving clockwise like a clock. If I turn the key on, the gauges reset and if I start the van everything is fine unless I load up the electrical devices.

I have changed the Alt, Battery, ECM and cluster but still does the same thing.

One thing that might be possible is I had a small windshield leak close to the dash, but have had that for a couple of years.

HELP!

1994 travel time chevy g20 conversion van.

8 Replies

JDL

MECHANIC
16,098 POSTS

As far as the alternator and battery, did you do testing with everything hooked up on the the vehicle? The alternator and battery maybe fine, but, if a wiring circuit has a problem, replacing the part won't fix it. The generic spec for a fully charged battery, with everything turned off, is 12.6 volts. Start the vehicle take second reading across battery posts, the second reading should be higher than the first if charging system is working. Engine running, if reading is below 13 volts, you have a weak charging system for some reason? Have you added anything that would increase electrical load? Thanks for the donate.

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Monday, November 1st, 2010 AT 2:04 PM

JERRYPCMAN

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All that checks out. But once I start turning on power items, any power items, the voltage drops and the van will not shift out of second gear. With normal day time driving with no ac it runs fine.

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Tuesday, November 2nd, 2010 AT 9:02 AM

JDL

MECHANIC
16,098 POSTS

All that can't check out, if the voltage is dropping. Engine running, the voltage shouldn't drop below 13 volts, with everything turned on, in my opinion.

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Tuesday, November 2nd, 2010 AT 3:04 PM

RASMATAZ

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75,992 POSTS

Check and test the guages fuse 20amp and all the ground points-if all ok -bring the alternator in and have it load tested-A good alternator should put out 13.5-15.5 volts loaded or not-see Charge EWD below

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Wednesday, November 3rd, 2010 AT 3:40 PM

JERRYPCMAN

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6 POSTS

Everything checks out. Could it be possible that a short somewhere near the cluster could be draining the voltage? Thats why the gauges go crazy under a load? Like I said before, even with the car off, if I push the break, honk the horn, push the door locks, the gauges start moving clockwise as long as I put a load on the car.

Would the next step be start pulling fuses until the fault stops? At least that should isolate the issue.

One last. Voltage flows from Neg to Positive right? So since the fuses are at the last point before the positive side of the battery, and there is a short to ground up stream, will this even work as a testing procedure?