ClassicFiero Electrical Drain Issue.

[Vtomanov]

There must be someone out there that tracked there car and found the drain problem that happens on all Fieros ever made. For many years the drain issue has been a mistery and the fuse pulling method never got me to the solution. I want to get an average of what people have found on there cars so please post a note on how you solved your Fiero Power drain problem. I personally know 5 people with these cars and every single one of them will kill the battery in 2 days. I drove 3 fieros back in the day and every one had this probelm. Now the legacy lives on in the cars we have turned into kits and even stock Fieros. Again please post what you have found as the leak. My guess is maybe the radio or some relay somewhere, very frusterating and no one on the web has posted a solution. Waiting for you help!!

['88 Dread GT]

Originally Posted by Vtomanov

There must be someone out there that tracked there car and found the drain problem that happens on all Fieros ever made. For many years the drain issue has been a mistery and the fuse pulling method never got me to the solution. I want to get an average of what people have found on there cars so please post a note on how you solved your Fiero Power drain problem. I personally know 5 people with these cars and every single one of them will kill the battery in 2 days. I drove 3 fieros back in the day and every one had this probelm. Now the legacy lives on in the cars we have turned into kits and even stock Fieros. Again please post what you have found as the leak. My guess is maybe the radio or some relay somewhere, very frusterating and no one on the web has posted a solution. Waiting for you help!!

My Fiero's trunk light switch cracked where it screws onto the latch causing it to misallign. Hence, the trunklight stays on even with the deck lid closed draining the battery.

[Old Lar]

I've owned Fieros since 1987 and the only time I had a battery drain issue was when I left the rear view mirrors courtesy light on or as in the other thread the trunk light stayed on. May be a ground issue or you can just get a battery switch that cuts the power off when the car sits.

I still have my original 87 GT covered in the garage with a battery tender hooked up, just in case. Its on its forth battery now.

[Ragtop_Renegade]

I had a 86 Fiero for several years. It was in need of a battery when I bought it, and being a bit short on cash I picked up a rebuilt (cut open, plates redone, top plastic-welded back on, filled with new acid) battery for $20. I had always intended on replacing it with a new one, but it just kept on going, so I never bothered. The car often sat for weeks at a time, plus all winter long. The battery was always at full power, and the iron duke cranked over without issue.

Something that ties in close with what others have been saying: My decklid light did not work. The bulb was burnt out. I could have easily replaced it, but never bothered. It doesn't cast much light, and I almost never had the car out after dark anyway. (we have highway wandering deer in these parts, a hazard for any vehicle, especially a little plastic bodied 2 seat sports car)

That always-on trunk light could be a really common issue, don't you think?

[Ragtop_Renegade]

I was at the auto parts store today picking up a can of ether (my Quadrajet equipped Chevy has a messed up choke and doesn't like to start in the cold) and I happened to notice a little device that connects between the battery and the positive cable. If the battery level drops below a certain point, it automatically disconnects, saving the battery with enough current to allow cranking. A simple push of a button reconnects the battery instantly. Remote models are available that allow you to put the reset in the passenger compartment. The cost is less then $70, about the same as a good quality lead acid battery. If you can't find the source of your electrical drain, this may be of help.

It's worth mentioning that every time the battery is disconnected, the ECM forgets some of it's learned behaviors and has to learn them all over again, but this is easily avoidable by running a wire (and in-line fuse) before the battery monitor directly to the ECM always-hot 12v lead.

[joefiero]

I had an electrical drain issue with my 86 GT 4 speed manuel. I searched everywhere, including removing all of my interior and double checking every wire and connection with no luck. I also checked all wires, sensors, sendors, relays and connections at the engine compartment, still no luck. I even added an extra 4 guage copper ground wire from the block to chassis and yes i also checked the trunck light, yet no luck. I decided to rebuild my headlight motors cause they were not opening all the way, stripped gears. This is where i found my drain issue! The headlight motor actuator (limit switch) not disconnecting the supplied 12 volts when headlight is all the way up or down. You can hear a slight ticking noise at the actuator, this is the little glow bulb inside the actuator that when the motor stops in the up or down direction builds up current enough to spin the headlight motor another 1/2 rotation to disengage the limit switch. My limit switch was worn out. These parts are very hard to find so i tinkered with the existing ones. The limit switch looks like a set of dual points and there is 2 mechanical arms that sit between them. these arms move only under the compression of the spring that rides the shaft. When these arms move in either direction they push against the limit switch to disengage the 12 volts in the up or down position which in turn tells the motor to stop. Mine were not disengaging completely and even that little glow plug could not supply enough juice to disengage them. So what i did was add thickness on the limit switch itself where the mechanical arms make contact, i used solder on the copper limit switch, but i had to adjust the thickness of the solder just right. Too much solder will not make them work properly. After performing this procedure my headlight motors work like brand new and most importantly my electrical drain issue was resolved.

[rogriffi62]

I have an 86 SE and one night after shutting it off I went around the front and heard the passenger headlight motor trying to turn. That was my electrical drain.