Getting closer to getting my car running (Page 1/2)
Carlin NOV 25, 02:45 PM
so my uncle who is a mechanic took a look at my car on Sunday. We used a circuit tester and power seems to travel through the car just fine. It even gets all the way under the dash to the fuse box and other wires. But the car still won't turn on. He told me to buy a proper battery to see if that fixes the issue. Im going to buy one soon to see if it fixes it but its a bit confusing since when I had power last time I used a jump starter and it worked, but now it doesn't. So I'm going to buy the battery and update you guys on what happens. In the meantime I would appreciate it if you guys have any other ideas of what is causing the no power issue.
82-T/A [At Work] NOV 25, 04:37 PM
If a battery is allowed to sit dead for too long, it will in fact die and often cannot be revitalized.

If your battery keeps dying, there's probably a "parasitic draw" that is killing the battery. In an old Fiero, the only thing it realistically could be is a relay that's gone bad (and stuck on), a failing headlight motor that keeps running, or a door / hood / trunk switch in which the light bulb stays on for too long.
Raydar NOV 25, 08:32 PM
A stuck oil pressure switch can kill a battery overnight.
If it's quiet where it's parked, you should be able to hear the fuel pump running, if that's what's going on.
DaveB1701 NOV 27, 12:26 PM
Been there...the aftermarket door jamb switches are crap. Purchased two from the Fiero Store, and killed my battery twice upon not shutting off the footwell lamps...tried two more from Autozone, and they stick on occasion. Whenever I exit the car now, I ensure the lamps have extinguished...
Carlin NOV 29, 02:51 AM

quote
Originally posted by DaveB1701:

Been there...the aftermarket door jamb switches are crap. Purchased two from the Fiero Store, and killed my battery twice upon not shutting off the footwell lamps...tried two more from Autozone, and they stick on occasion. Whenever I exit the car now, I ensure the lamps have extinguished...



wait sorry if I confused all of you guys. the battery I was using is fine. its just that the car no matter what wont get any power. it travels through the car just fine but literally nothing turns on. my uncle said the battery might be too weak so just today I bought a proper battery fro the car. I will install it tomorrow.

one more thing. I've used 2 jump starters and 2 batteries but nothing works. Let's see if a proper car battery does the job.

[This message has been edited by Carlin (edited 11-29-2025).]

Cajun NOV 29, 10:05 AM
Carlin,

If you do not have a Factory Service Manual for your vehicle you definitely need one to assist you in sorting out the wiring and circuits. The FSM is available free online if in need of one.

A suggestion, if you have not yet done so check all the fuse links.

Riney NOV 29, 10:09 PM
Yes, check the fusible links
cartercarbaficionado NOV 29, 10:34 PM

quote
Originally posted by Carlin:


wait sorry if I confused all of you guys. the battery I was using is fine. its just that the car no matter what wont get any power. it travels through the car just fine but literally nothing turns on. my uncle said the battery might be too weak so just today I bought a proper battery fro the car. I will install it tomorrow.

one more thing. I've used 2 jump starters and 2 batteries but nothing works. Let's see if a proper car battery does the job.



since no one can link things anymore.
https://fieroinfo.com/manuals/
its probably the fuseable links or you have some connection issues. test light and multimeter will help immensely, if you need extra help pm me and i will check my fiero to help you.
please do check your ground wires and main positive since mine lost all power when the main ground failed which happens
Riney NOV 29, 11:02 PM
Yes, check the fusible links
fierosound NOV 30, 11:28 AM

quote
Originally posted by Carlin:

wait sorry if I confused all of you guys. the battery I was using is fine. its just that the car no matter what wont get any power. it travels through the car just fine but literally nothing turns on. my uncle said the battery might be too weak so just today I bought a proper battery fro the car. I will install it tomorrow.

one more thing. I've used 2 jump starters and 2 batteries but nothing works. Let's see if a proper car battery does the job.




I see from a previous post, you've had ongoing electrical issues resurrecting your 86 SE that has sat for 30 years.
Your C500 connector and Battery Junction Block (usually the culprit) looked OK in the pics from what I could see.
https://www.fiero.nl/forum/Forum2/HTML/148828.html

This is the Power Distribution wiring diagram for the 86 to follow, once you have a good battery in there.
In the 1986 Factory Service Manual, pages following these identify locations of all the components.





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[This message has been edited by fierosound (edited 11-30-2025).]