Okay, my black Trans Am has some issues that are confusing me.

My red Trans Am, which gets started once every two weeks, sits in the garage with the anti-theft system off, just the doors locked manually (no electrical draws except the time on the clock, PCM?). Every two weeks, I go in there to start it to drive around, and it starts like a beast.

Now...

My black Trans Am... It always runs low on volts when at a stop, and if I have the AC on and/or the fans are on high speed, the volts drop to about 9/10, visibly slowing wipers, the AC fan speed, slightly dimming lights, etc... AND, if I don't start the car in four/five days, the car will hesitate starting... It will be fine again after driving around for 20 minutes and starts again fine the next day (charged). If I don't start the car for more than a week, it will not start, and need a jump start.

I've taken the battery to get charged, gone through several batteries, and I have gone through three alternators (Napa, AC Delco), and this behavior remains the same... If I start the car every other day or every three days, it will always start like a champ, and never need a jump (it will, however, behave as described when fans go high speed). If I wait over a week, it will not start. It throws no codes, I've checked all grounds, checked all connections, terminals, and exciter wire, and a mechanic tested the charging system for me and says it charges fine... I told him to wait until the car warmed up and the fans went high speed... He did, when it did, I put the car in drive, holding it with the brake. Volts went down to like 9 (in the yellow), and all electrical components slowed... The guy couldn't explain why that happened and was confused himself. He offered to test every single wire in depth over a day looking at it, and I told him I might go back.

Anybody had this problem? It pisses me off because sometimes I'd like to leave the car off for a week, but I don't like disconnecting and connecting the battery weekly just for a quick drive... I'm not driving the car every day now, and I don't have room in the garage for another car to have it on a tender maybe. Plus, its behavior at a stop when the fans are on high speed is worrying me...

Thanks for reading and I appreciate any input! Again, consider, this has been with three alternators over the last three years (used to drive this car daily, so none of this was that big a deal, it would start fine), and two batteries that have always tested fine (Optima red tops), so alternators/batteries have been pretty much ruled out... The local mechanic said they tested fine anyway.

 

What tpye of battery do you have.
I had a red top and it kept going down. I changed battery to the best battery Sears make. Don't have the name of it right now.
Also those alternators is the problem. Replaced three types of alternator. Had a guy in Suffox, VA, by the name of Mr. Joe, build me a high output and haven't had a problem since with voltage.
Check on here about replacing the alternator for the trucks high output alternator.
Hope this help you out.

 

Sears huh? Yeah both batteries in this car have been Optima red tops.

The alternator in it however is already high output (160 amp). After a Napa crapping out on me and an AC Delco crapping out on me, I bought a high output alternator from the same seller and same specifications as the one on my red Trans Am... The one on my red Trans Am has lasted for years and charges great...

But the car has behaved IDENTICALLY with all three alternators! lol damn problem at a stop has never changed... I've dealt with that for years... The problem now is that I got another daily driver and I'm no longer starting her every day. One week without starting and bam, battery is cashed. Then I get the battery tested and they tell me it's fine, just discharged... Wtf?

I figure both problems are related, but they seem to be unrelated to both the alternator and battery... Any other opinions before I go to Sears? lol

 

For one thing, you have a parasitic draw somewhere. Try this, when you park the car, disconnect the battery and leave it that way until you go to start it in a week. Connect the battery. Does it start now? If so, you definately have a large parasitic draw that needs to be located. I don't know if it has anything to do with your second issue of low power while driving sometimes, but it is a start.

You'll need to do testing to determine was is causing the parasitic draw if you determine that is what is causing the battery to die in a week. Usually pulling fuses while having a volt meter going will find which system is causing it.

 

Haven't done any volt testing. Mine is still working like a champ since getting battery from Sears (the one that was put in ice and still start the vehicle up).
If it happen again I will check the voltage.
I don't drive my car maybe once every two weeks.

 

I'd love to be able to turn my car on once every two weeks... That'd be perfect.


So, I'm ready to start testing for the draw, and I've read to set the meter to 20A... I'm a bit confused because I've read conflicting instructions on where to place the leads... Some sources say to unplug the positive battery terminal, placing the leads between the positive battery post and the positive battery cable, and other sources say to unplug the negative battery terminal, placing the leads between the negative battery post and negative battery cable.

How is it really done???

Btw, I've greatly improved the volts while driven by raising my car's idle rpm... That's much better now at least.

 

Anybody?