Battery Drain

[Wayne Pickelsimer]

I have done all of the tests that I have seen for a parasitic battery drain. There is no change when any of the fuses are pulled. I made sure that the door was closed when I checked each fuse. Nothing was on. The key was in the off position. I have ruled out the alternator. I disconnected the wires from it joined them and still have the drain. It is 3.25 amps. The car is a 73 Grand Am. Should be simple right? I dropped the starter and checked all of the wires, they are good. I pulled the battery cable and checked it, good. I am running out of clues, as a matter of fact I am clueless. :S

Topic

[Richard Kirshy]

3.25A draw…
Have you checked for any possible faulty relays?
Possibly a defective ignition switch.
Perhaps something in the AC compressor clutch or maybe a bad sensor
May need to get old school on it and start isolating sections of the electrical system starting with the starter and alternator by removing the positive leads.

[Wayne Pickelsimer]

Just to let you know, I am more of a parts replacer than a mechanic. On this car I had no problem with this up to now. Replacing 40 year old parts was not an issue. I have taken the alternator out of the equation. There is no air conditioner on the car. If I disconnect the wire from the alternator to the starter the draw goes away. Of course I have taken power feed from the alternator. If I connect the two wires off of the alternator the draw is still there. Just not sure where to go from here.

[Richard Kirshy]

[quote=”waynega73″ post=173933]Just to let you know, I am more of a parts replacer than a mechanic. On this car I had no problem with this up to now. Replacing 40 year old parts was not an issue. I have taken the alternator out of the equation. There is no air conditioner on the car. If I connect the two wires off of the alternator the draw is still there. Just not sure where to go from here.[/quote]
I am assuming you mean the heavy battery positive cable, what happens if you leave the cable on the alternator and remove the positive heavy cable from the starter? The issue appear to be either the alternator or starter

What power feed?

Again.. what 2 wires??

Attachments:

• currentdraw.png

[Shaun Flichel]

Agreed with the above. If pulling all fuses leads to no change, it’s something inline that’s always live. Starter or alternator

[Wayne Pickelsimer]

By feed I was refering to the wire from the alternator to the starter that is in contact with the battery cable. I thought that I found it today. With the wire from the alternator to the starter removed from the alternator there is no draw. I reinstalled the starter. If I disconnected the plug on the alternator, field and sensor, the draw went away. I thought that I had at least found the wires to trace. After a little while, without the plug on the alternator, I have a 5.25 amp draw, If I connect the plug on the alternator it goes up to 7.25 amp draw. Now I am really getting confused.

[Its me]

If you get rid of the draw when you have disconnected your alternator then your alternator has a bad diode. Most likely easiest just to replace the whole alternator.. if there is still a residual draw, keep looking.

[Rob]

did you say you stil have a large draw when you removed all the fuses both in the car area and the engine area you removed all the fuses and relay??? if not… lable with a chart and pull them out… if you still do there are not many things that can still draw power

[Wayne Pickelsimer]

There are no fuses under the hood on this car, and yes after pulling all the fuses the draw was still there. As of right now my next step is to have the alternator tested.

[Rob]

[quote=”waynega73″ post=173997]There are no fuses under the hood on this car, and yes after pulling all the fuses the draw was still there. As of right now my next step is to have the alternator tested.[/quote]
what kind of car is this???
make/model/year/8th of vin/ engine size

[Richard Kirshy]

By everything your describing your looking at a faulty alternator

[Wayne Pickelsimer]

The car is a 1973 Pontiac Grand Am. The car came with a 400, it had a 350 in it when I got it, now it has a 455. The eighth digit of the vin is 4

[Wayne Pickelsimer]

Ok, got the alternator checked and it was bad. However, it was just part of the problem. After replacing the alternator and isolating it from the rest of the car there was not draw. With everything back in place I now have a 5.5 amp draw. I disconnected each wire from the alternator until the draw was gone. Checking the wiring diagram for the car, it now seems to be coming from the lighting circuit. Now I have to trace that down.

[Author]

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