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.
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.
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.
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...
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).]
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.
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
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.
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.
I'll try to look at it as soon as possible. I didn't get the battery in due to snow. and it has been below 32 degress for the past week. hopefully I get at least one warm day so I can look at it more with my uncle
he also said I need to read the whole manual that I have so I can help him work on the car. I might start doing that tonight so I can get something done on the car
[This message has been edited by Carlin (edited 12-01-2025).]
Did you check the power junction connections on the wheelhouse near the battery? If those nuts are not tight power will not reach the ECM.. To start the engine you need power to the ECM, power to the injectors, fuel pump, and power to the ignition system. When you turn the ignition key to ON does the instrument panel show any lights? If you tur I n the key to start does the starter engage?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Did you check the power junction connections on the wheelhouse near the battery? If those nuts are not tight power will not reach the ECM.. To start the engine you need power to the ECM, power to the injectors, fuel pump, and power to the ignition system. When you turn the ignition key to ON does the instrument panel show any lights? If you tur I n the key to start does the starter engage?
like I said, nothing turns on but power travels through the system. the junction box works, I fixed that last week. and i did test the ECM. power does go in and out of it. the main wiring harness by the battery works to.but nothing turns on
turning the key does nothing. btw even with no key the inside lights should turn on when I open the door. but nothing happens
[This message has been edited by Carlin (edited 12-02-2025).]
like I said, nothing turns on but power travels through the system. the junction box works, I fixed that last week. and i did test the ECM. power does go in and out of it. the main wiring harness by the battery works to.but nothing turns on
turning the key does nothing. btw even with no key the inside lights should turn on when I open the door. but nothing happens
If you check for power at the fuse box all circuits there should energize. If no power there check the ignition switch that is under the steering column.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
If you check for power at the fuse box all circuits there should energize. If no power there check the ignition switch that is under the steering column.
yay, btw I covered my dads face and the plate for privacy Incase anyone was wondering.
