So for about 5 years now my '86 Trans Am has had a nasty habit, if one does not go out and start her once every 24hrs, the battery goes dead.
I stopped driving my TA not long after as I needed a cheaper mode of transportation to my job (which was a longer drive now) So that project sat on the back burner until now. I've been messing around with my stereo and other much needed projects on her and have a couple of questions.

I did have a new stereo installed (a clarion DBX something or another a few years prior to the draining). Recently, my brother decided he could fix the problem by disconnecting my memory lead for the radio....I laughed....and was annoyed that I would have to reprog my radio every time BUT it worked....sorta. The drain now took over a week to kill the battery as opposed to a single day.

I've been installing a set of subs and amps in the rear lately and have taken this opportunity to check EVERY piece of wiring that I can find for some type of short. Thus far, nothing. Under the hood, there were a couple of wires I found that the casing had rotted off and corroded the wires badly, an easy fix for me and my soldering iron and I was back in business...the drain continues.

Is there anything simple I might be overlooking? I assume the reason cutting the memory lead for the stereo adds length to the drainage time is because it does draw a small amount of power from the battery all the time and just pushes it over the edge.

I suppose it is possible that the stereo has a problem now and draws too much from the memory lead? I am planning on picking up a volt meter tommorow and checking into this. Any suggestions are appreciated.

If I can figure it out I'm going to have to take it too a pro and have them go through the whole thing (but I'd love to solve it myself)

 

https://www.thirdgen.org/forums/elec...ery-drain.html

A good link on how to test for a drain- posted just a few days ago. Let us know if you have any problems or questions. Here to help.

 

Yes, after posting I dug a little deeper and found some good info on the subject. Although most don't have final conclusions to them! I'm off to buy a volt meter.

 

I had the same issue with the same year/make. Funny. I am a 12volt electrician and have yet to determine the source. I have eliminated the aftermarket stuff, since I dont drive it regularly. Let me know what you find. Ill do the same if I get some time to check it out. Mine took 2-3 days.

 

I am assuming you have had the battery tested?

 

Thanks Mr.Obvious! (laughingly), but yes I've actually changed batteries several times (my brother sells them).

BUT I do have news to report. I used my new voltmeter and voila I was pulling around 5.8amps with the car off!!(I believe I found a post stating like .4amps is normal for a TPI car). So the next thing I did was to remove all the fuses from under the dash...now I got a reading of 2.85amps...better, but still not great. Next I disconnected the alternator...down to 2.12amps...hmmmm. Then something caught my eye (ouch) near the distributor under the top aluminum thing (Sorry, don't know the proper term) there is a sensor...with two wires running out to a plug. The wires were nearly bare and wrapped around each other. The best I can figure is over the years chemicals and friction have worked thier magic and eaten through the thin casing leaving the two wires to either touch or rub against any number of other metal items. I unplugged the sensor (still not sure what sensor it is) and my voltmeter showed 0 draw (well actually .00012). Eureka!

I played around with sensor wires but couldn't get it to draw any large load again so I couldn't truly verify that this is the problem BUT its definently something I need to fix. Anyway, does anyone know what sensor I'm talking about and should I replace the whole thing or just patch the wires? Also how the frak do you get it out with our removing EVERYTHING!

Anyway, then when I returned all the fuses to thier proper places I still only had a load of .00020amps

Hopefully I've done a decent temp job on the wires until repair can be accomplished.

One last side note, when at idle with headlights on what should the draw be for my car? I know this will be somewhat subjective but I've noticed that when I do this and then hit the turn signal, my amp meter just bounces away with the signal and tends to drop pretty low (bouncing into the red zone). Just driving down the road I tend to never show anything above 13amps, more like 10-11.

 

I'm guessing it is the MAT sensor, can you tell what the wire colors are? IF it is, you would just have to unbolt the plenum + TB and lift up- 14 bolts. You should not have current going to ANY engine sensor with the vehicle off, did you re-check your amp pull after replacing all the fuses?

 

Rechecked amp pull after all fuses were back in and thats when I got like .00020 pull (which is ok) I think your right about the MAT sensor and the wires are redish & black.

So I will probably go ahead and replace the MAT sensor since I'm sure the wires touching couldn't have been very good for it!

Thanks

 

Checked out the MAT sensor, seems fine (unhooked it and ran the engine to see if there was a difference, ie was it working in the first place) and yes it was, SES light came on after only a few seconds (and the exhaust wreaked of gas).

So I think my draw is fixed! Unfortunatly I brought the car home tonight and my rear hatch pull down mechanism won't work! ARGGG, no idea whats wrong with that...checked all my fuses and they look good...everything else works so it probably a loose connection ( I was in that area doing wiring a couple days ago) or the motor has died.

BTW how do you get the stupid thing to latch IF the motor is dead?

 

I'm a bit concerned that your MAT is even being supplied with power with your ignition off... anyways...

Sometimes if the hatch pulldown isn't latching, I have to use a screwdriver into the latch and try to get it to pull it down (it takes some fumbling)-- then hit the hatch release. It won't catch if the latch/ motor isn't completely in the UP position. For the time being you may have to PULL the motor up and use some zip ties to hold it in place so your hatch can shut. Most likely the motor is good, the housing for the ballscrew often breaks or the track bushings crumble- from slamming the hatch. These units are very sensitive- make sure not to slam the hatch shut and shut it or release it while the motor is running.

 

I agree with you on the MAT sensor getting juice, doesn't make sense except thats what seems to be the problem. Since moving the wires apart I haven't had any draw. Now I do have some strange problem with my stereo now (perhaps a loose connection) but only on the speaker side so its not drawing any juice till I key it on.

As for the rear hatch, when I bought the car (9 years ago) the hatch didn't work and was stuck closed. After about 2 years I had it repaired and its worked great since then! I'm going to check all my connections too just in case.

Thanks for all the help! I'll keep you posted on the electrical issue as well!