Oil pressure gauge is pegged high 1 year ago. Left turn signal didn't work two months ago. It was a burnt bulb. Two months ago power drain and dead battery. 2 new batteries have been killed with dead cells. Starter changed, alternator changed at the dealer. Picked up the car and 4 new problems. AC doesn't blow only the vent. Power windows don't work/ Power locks don't work. choke light and buzzer on and the choke is on. They gave up and had to jump the car to get it home from the dealer. Where would you start? Trace or replace? Please help. Thanks

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Original owner
85 Z28
Goodwrench 350
SLP headers exhaust
dual cats
leather interior

 

Parasitic drain somewhere...Looks like you got a lot of trackin to do- good luck!

 

if your battery keeps going down, pull one fuse at a time and leave it overnight and see if thats where your drain is comming from, if not, replace the fuse and move on to the next one.

 

That could take quite a while.

Why not disconnect one battery terminal, connect an unpowered test light between the battery and removed cable.

Uplug the dome light and underhood light. Make sure no lights are on at all.

Pull all the fuses and breakers in the fuse block. Pull any underhood fuses/breakers.

The test light should go out. If it doesn't, the drain is not related to any fused items. If it does go out, replace fuses one at a time. Any that cause the test light to come on are suspect.

 

What Brent said is actually a very good idea. I would also suggest disconnecting the ECM and anything else that continuously draws current with the engine off (like the radio memory, an alarm, etc.).

It seems like you have a multitude of problems. I would be especially concerned with having to replace two batteries for the same problem - dead cells. The $80 question is why. While it may not be probable that you got two new batteries that were defective for the same reason, it certainly would not be impossible, especially if they came from the same lot. The following are some reasons why a good battery will fail prematurely, but not necessarily due to a bad cell(s).

1. Loss of electrolyte. This is the most common cause, often due to high temperatures under the hood.

2. Many deep discharges. I wonder if this caused your new batteries to "go south". Determine if something is drawing current with the engine off (other than the ECM, radio memory, alarm, etc.). The parasitic (key out) load should be under ~200mA, preferably ~50-80mA. Frequently listening to the stereo with the engine off could also cause many discharges.

3. Using too small a battery for your application.

4. Not being charged properly. This could be anything from a loose alternator belt to not letting the engine run long enough to recharge it after being started. This is similar to point #2 above.

5. Vibration.

6. Not using pure enough water to fill the electrolyte. Tap water should not be used.

7. Freezing (wintertime) and corrosion can also cause premature failure.

I would be very concerned that the Chevy dealer gave up (presuming that it was because they could not solve the problem, and not for financial reasons...). It's certainly not rocket science to someone doing this for a living (a dealer). What's wrong with this picture?

[This message has been edited by Stuart Moss (edited July 28, 2001).]

 

Stuart, Thanksfor the reply. I think that the dealer gave up because of finacial issues. I was willingly to pay. However they don't think it's worth their time. The service manager tried to sell me a new car!

The two batteries were from Sam's club. Probably too many deep cycles. My charger works fine on my boat batteries. The battery maitence is not on issue. Third battery is OK . I keep the terminals disconected.

The milliamp parasitic load is good info. I will buy a ohm meter in AM. ( My Dwell/voltmeter doesn't have amps readings)
I can still see small sparks when I touch the neg cable to the neg terminal. The draw is too small to light a 1157 bulb. I saw the sparks during all serial pulling of the fuses. I have pulled 85% of the dash. the connectors have been pulled from the console power windows, dome light, radio, all gauges, computer,

I assume I'll have to trace all wires for parasitic load. Any body with suggestions where to start or better yet an algorythim to follow? Any help is very much appreciated.

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Original owner
85 Z28
Goodwrench 350
SLP headers exhaust
dual cats
leather interior

 

MY85,

Unable to light a 1157 bulb could be good. They (1157NA) typically draw 2.1 amperes at 12.0 volts and 0.59 (590mA) at 14 volts depending upon which element you are lighting.

Seeing only a small spark when attaching the battery cable is also a good thing. That's normal for the ECM/radio/alarm circuits that always draw current.

I think getting an ammeter (Radio Shack will probably be easiest - tell them what you want to do and they should be able to show you how and advise a cheap [$15-20] analog unit).

Let us know how many amperes the battery is providing with the everything off. Make sure you start reading with the highest ampere scale to reduce the risk of blowing the ampmeter fuse. If the light does not illuminate, you'll probably be safe on the highest scale on the ampmeter.

If you see over ~200mA, isolate the problem by removing one fuse at a time to see what is causing the excessive current draw. Don't forget to remove the fuse by the battery (I have one on my 91), as well as all the alternator connectors in case something there is causing the draw.

 

One thing I've seen that may help your tracking is an inductive ammeter. Basically it just hooks around a wire, and will read the current going though it, without having to splice into it or having to find a connection or anything. So you can check anywhere on a wire. I don't know how sensitive they are though (if you're getting into mA's), and the one I saw was quite big, but you might be able to find a smaller/more sensitive one. Just a thought.

- Mike

 

In my regular job, I try to tied all problems to one problem. I am concerned that there maybe a problem with a major harness to explain all. However it is possible, with the age of the vehicle, that sevral small problems are present.

The Helm inc manual is out of print. It sure would be nice to have an flow chart and wiring diagram.

On the visual inspection the Plastic behind the oil pressure sender unit is charred - discolored looking.

The light switch has a lot of corrosion aroung the dimmer switch copper arm. The connection/harness is melting and a bromn or black wire is loose from the harness.

The service man at the chevy place said the relays on the power windows were bad. Can anyone tell me were they are located? How do you test a relay in general? How do I test the AC rotor assembly?



------------------
Original owner
85 Z28
Goodwrench 350
SLP headers exhaust
dual cats
leather interior