BRoss99

Hey guys kinda stumped here. I have a 1988 Pontiac Firebird 5.0L TBI 5speed, and i have no power to the door locks, power windows, headlight motors, gauges, interior lights, ignition, radio. Still have power to interior lights and the parking lamps and all the fuses that dont require switched power.

Now i have tested a lot already:
engine grounds , all fuses in fuse panel, some length of power wires coming from battery, i have put in a brand new starter switch module(electrical switch) and tested the connecting lever rod thing that connect from the key to this switch box. Also i can here the relay clicking when i try to use the power door locks.

Im thinking its a fried ECU, wanna check with you guys before i go with a new MSD Atomic TBI.

sofakingdom

iTrader: (1)

Not the ECU. That has nothing whatsoever to do with windows, headlights, etc.

See my signature for a helpful logical hint when troubleshooting: namely, if your proposed "explanation" doesn't fit the facts, in this case if it's impossible for it to create the symptoms being observed, then it's wrong. Discard it immediately.

It's a fusible link, down by the starter.

The way the car is wired, the connections that connect the "car" to the battery, are at the starter, at the far end of the red batt cable. Obviously that point is electrically the same as the other end of the batt cable for most purposes, so it makes a real convenient "binding post". Look at the big terminal on the starter solenoid that the cable goes to; in addition to the cable you'll find about 2 or 3, most likely 2, smaller wires as well as the batt cable. Those each provide the power to about half of the rest of the "car". So what you have now is, about half the car works, and about half of it has no power.

The wires themselves at that terminal are a short section of smaller wire that acts as a fuse, to protect the big power wire behind it. One of them, the wire has broken. Just replace em both. You can get fusible links at parts stores; a 50 amp one should work fine for each of the 2. NO HACK JOBS here; no substitution; no "just get it running and I'll finish later"; NONE OF THAT. Just get the right thing, do it RIGHT, and you'll be AHELLUVALOT happier for it, than trying to hack something into there.

BRoss99

I think this binding post u speak of is right beside the battery. it lools like mabey this car has been rewired cause there are some type of crimps with orange wire going to red wire. One wire goes to ecu one to alternator one to starter and i think there may be one more.

Ill hop down there today tho and look at the starter solenoid. Thx for the great detail amd quick response

BRoss99

Alright found the fusible links. I missed these i checked the other fusible links. These bad boys where hiding up in the starter. The link fell apart when i disconnected the connector lol

sofakingdom

iTrader: (1)

Those things in the picture are all from the factory. The orange section of wire is the fusible link part. The post they go to is part of the starter solenoid, which is why the big red batt cable goes there. All of that is exactly what I was pointing you toward, so it's no surprise that you found one was bad.

DO NOT try to replace them with regular wire!!! You can get fusible links in the electrical section at the parts store. They're actually color-coded; just get one the same color as what you have. They actually call it "rust". Replace that, it'll fix you right up. Might even want to go ahead and change out all 3, since any of them could also flake at any time as well. Just make sure to do a REAL GOOD job of attaching them so you don't introduce intermittents, bad connections, hot spots, etc.

BRoss99

Got some fusible links same gauge wire 16*. And car ran fine but blew another link. Appears to have a ground short wich makes sense cause before the fuse blew the tach was acting all weird and the one headlight motor kept spinning longer than it should. Thx for pointing those out tho they where hiding underneath the motor.

sofakingdom

iTrader: (1)

Well I guess the link is doing its job then...

Now all ya gotta do, is find the short.

I'd suggest getting a wiring diagram for your car, and first figuring out what all the link in question powers. Might include some things that aren't totally obvious; for example, might feed the terminal strip up on the left kick panel above and behind the parking brake release cable, which powers various accessories like power seats, power windows, and so on.

Put in a new link but don't hook it up yet. Use an ohmmeter, measure resistance from that wire to ground. Disconnect things one at a time until you find the one with the short. Operate each switch (ign, headlight, etc.) if it doesn't have a short with everything off, see if the short is downstream of any switch. Not much fun tracking down a short really, might be easier if you know of things that you or the PO has worked on, and examine those places carefully for mistakes.

BRoss99

Ok thx man there was smoke outa the loom so im pretty sure i found the spot where the short is.

alex722607

iTrader: (3)

Honestly I am not surprised someone has had an issue like this. When it comes to wiring with these cars, the factory did a ****-poor job in designing it. I first had an encounter with this issue, when my alternator started doing funny things. The alternator stopped charging the battery and upon close inspection it turned out to be a connector at the starter. Upon fixing that, a week later my car became a dead hunk of metal, with no power what so ever. It turned out to be a fusible link at the starter. Since switching to 4th gen wiring for the body and engine, I have not had any complaints. I am actually going to redesign my old 3rd gen TPI engine harness to make it more like the 4th gen one.

I hope that you find your issue and please report back with your findings. I definitely am very interested in this because it may help me when I redesign the harness.

BRoss99

So replaced the link blew again. Thinking theres a short on the popup headlamp as its acting funny. Gonna tear up that harness when i get some time here.

alex722607

iTrader: (3)

The pop up headlamps have their own fusible link just after the module. Both left and right has its own. I think you should consider removing the harness from the car and unlooming the whole thing.

BRoss99

No sense in doing that and all my fusible links are in one area so idn which ones which. But this ones for switched power which might have something to do with the headlamps. And i will be conducting an ohm test so theres no need to take it out yet.

alex722607

iTrader: (3)

Understandable... It is a pain in the *** to remove it. However the fusible links that are by the starter are not the only ones in the car. The fusible links that provide power to the headlamp module and therefore the headlight motors is about 6 inches away from the module on the firewall. They are in the loom. It's kind of stupid the way GM did it. They use the starter as a diffuser and send power inside the cab of the car. Then because there is things that need to be powered in the engine bay, they splice 5 or 6 wires into one of the wires that comes from the starter and send power back to the engine bay to power things like the headlight module and relays and fog lights.
Hope this helps.

Cleotiz

This picture just helped me a step in the right direction!
Woudl you please be so kind as to take a picture of your postive battery terminal as well?
So that i can see what the wires look like that are connected to the + terminal.
Much thanks!

Cleotiz

BRoss99

Can anyone tell me what size of fusible link the broken one is? I thought they where 16 but the broken one looks like mabey a 14

BRoss99

i can do that for yah give me a couple days

Cleotiz

Man, you are the best!

Also, where does the thin white wire go to that is in your picture?
And is there by any chance also a thin black wire that comes out of the harness at the same spot? Thanks!

Camodica

I have a 87 firebird 5 speed with the 350 and half of my gauges dont work. I saw this thread and was wondering if checking those wires on the starter could be the problem. Im at work and i cant check it until later but i figured i could ask and receive any info on this issue im having.

BRoss99

Mine ended up being wires that rubbed on the frame underneath the dash

Jim87Formula

Any updates on this? I checked my fuse links and they seem to be fine and power going through them. Mine first seemed that the fuel pump went out so it's been sitting for a while. I've had time now so I put a new battery in it and everything worked except it wouldn't crank. Took the starter out and tested it and seemed weak so I bought a new one. Well cranked it, nothing but after trying 3 more times it starting turning over but not starting. Checked spark and fuel but no fuel and I had spark. Took the fuel pump out and wanted to see if it was pumping and when I turned on the ignition everything shut off. No power anywhere.

Vgibson

hi guys. Will this be the same fix on my 85 Camaro? Mine us a 305 carb base model edition sport coup. New light plug for pulling lights on etc, but the one I took put was fine. Mechanic had no idea how to put the put the pull **** back and said it was defective even though it was new this fall. Was working fine. No Guage lights, radio, cig lighter, horn or interior lights. All outside lights work perfect, Checked fuses and only the 5 amp was needing replacement. The cd player is in mint condition and pro installed, Been working fine for a long time now right up to it going dark with all rest of the stuff. Found no wire issues with it. I have had heat issues with wire's getting hot from pipes but had them coveted. Checked them out and no burn or broken spots. . So perhaps I should have the red positive battery wire checked as you suggest? I drive my car every day and have worked on it for 17 years now. This car does not have the relay box on passenger side. Fuse box has only one silver 30 amp fuse style. Hope you may have an idea as to what I can do to get things back on. Thanks guys. I live in a small city in Canada and no one here seems to know how to trouble shoot except to take every wire out and charge a grand for the job! !! So help would be wonderful. I love my bluz car cheers!

okay

The best thing you can do is upgrade wire size by adding 0ga+ to alternator, battery frame and block. I always stay above 13v at idle.

Vgibson

Well, just a quick note, after reading about all the fusible links etc, I had found it to be the need to replace the ignition switch...it just no longer was engaging...so once that was replaced, all the power came back...! Who knew....however, I am going to go back to check the links, as I bet they are about done too. Thanks guys!! Camaro fan of my Bluz 85.

ItsAJeepThing

Where are those wires located I need to check mine nd I’m thinking that’s what causes my 87 to have no power pics would be helpful if you have them

Vgibson

I would love photos too of the type of wire you mean. I also found that the starter can get touchy if you don't keep it clean. Which I do alot. (the chrome dip stick tends to leak on it, so I need to seal that off again) There is a wire connection to it that gets a lot of heat, to which needs protecting, but was not set up that way. So I am getting a starter shield and redoing that small wire. As for other connections, check them over, as the motor gets hot in the back and the wires there get too hard and brittle after years of driving. I am planning to restore the wire harness. I have also learned how to rebuild my own alternator. Took it in for a check after and it was perfect! But with the extras now on the car, I may have to upgrade it.
Thanks for the help guys, and for having this board! It is great to have others out there who love this car! I am not rich, and I drive it everyday, but hey, better than sticking it away somewhere and never enjoying it, right? Life is too short, so drive them! It is not a carbon copy like so many cars out there, and they do turn heads even today. I got a kid who was restoring his own old truck give a thumbs up for my car! How cool is that! Will try to post pics of my car once I get the roof replaced and some new paint! Cheers!

ItsAJeepThing

Where is your ignition switch located and how easy was it to replace i have an 1987 5.7 with no power on key turn

ItsAJeepThing

where are those wires located under the dash exactly? need a point in the right direction

Onespeed

I myself am having issues, I blew out my dome light fuse but have no clue where that is to replace it. I saw that the other fuses are on the far right passenger side under glove compartment. But mine was owned by a mechanic who has the wiring in such a way that you cannot move under the dash without touching wires, relays, fuses, those black coil wires the linked fuses go throughout the car for me I'm guessing they are in the center under the dash. That's where they enter the car interior by the looks of things.

I'm sitting here fscksd my headlights switcher has gone mad and no matter what I try I cannot get my headlights on. I think I'm stuck in this parking lot for the night. And worst the 12volt accessory outlets were all wired to the dome light fuse I blew.

I just wish I had some.guidance
​​​​​​This situation sucks.