I was just driving along and almost all the electrical power in the car died. The engine stalled, and I saw all the gages drifting back to their off positions. Being a manual transmission I let the clutch out while the car was still moving and it didn’t restart.

Here’s a list of what I know so far…
The car shows no signs of life when I turn the key, no door chime, no check engine, no radio, no fuel pump prime
The headlights and running lights turn on, but the headlights don’t flip up, the gage lights don’t turn on, but the dome light goes on when the doors open. These lights seem to be really bright.
The hatch release works
The brake lights don’t go on with the brake pedal
The starter doesn’t click
The battery reads 12.5 volts
I have continuity between the 2 posts on the starter when I turn the key, this was checked with the wires disconnected from the starter.
The battery cable going to the starter reads .6 ohms
All of the fuses in the fuse block and the one next to the radiator for the ecu look fine, the fusible links by the starter look good too.

I was thinking the ignition switch went bad, but that doesn’t explain the brake lights. I can track one of the many wires that feed the car to the driver’s side firewall where it goes inside the cabin.

The car is an ’88 Formula, 305 TPI, T-5, manual windows and door locks. The only thing I have left to try (that I can think of) is another battery, after that I’m pretty much out of ideas. Does anyone have another idea?

 

Your battery should be OK. You have a Volt/Ohm meter? Use it to test the fuse links. You can't just look at them.

 

Sounds like the fusible links.

 

How do you test a fusible link? Just see if there's the same amount of voltage on the output end as the input end?

Do you have to replace the fusible links or can you just run strait wire? (or maybe strait wire with a removable fuse in it somewhere?)

 

That's weird, I've always thought a fusable link would melt away and leave a bare wire. That's what happened when my dad's car fried its fusible link for the cooling fans. It was really easy to find that way... I just had to follow the trail of smoke.

I'm checking all my wires by continuity, but from what I said above shouldn't the fusible links still show some continuity eventhough they could be bad?

 

IIRC the links are incased in a plastice or rubber sleeve of some kind. To test you have to check for 12 volts on either side.

The links cant be judged good by looks, though if its burned or smokes then its probably bad.

The link cannot be replaced with just wire. The links are there to protect the main circuts in the car. You may be able to put a inline fuse, but I wouldnt suggest it due to the location of the links. I'd put the links back on. Also, when you replace the link and if it blows again, dont replace it a 3rd time until you figure out whats blowing it.

Matt

 

So, will a bad fusible link still show continuity?

 

Test the links by disconnecting one end and checking with Ohmmeter, if bad it will read “open”. If you try to Ohm them without disconnecting at least one end of the link, a bad link can falsely read continuity.

Other way to test links without disconnecting one end is to use a voltmeter and check for voltage on both ends of the link. The circuit must be “on” to get valid measurements (turn the ign key to “run”). Should see 12 volts on both ends if good.

 

Well I figured it out. The short wire coming off the starter to the fusible link was broken. Actually, that wire has fusible link written on it too, and it kinda looked melted. After I replaced it and the fusible links with some more fusible link wire, I heard a pop from under the dash someplace.

It turns out the main harness that comes out of the fuse box was pinched between the box and a bracket that holds up the dash. It chewed through the insulation on one of the wires, and partly through 3 or 4 others. I taped it up and slit open some vacuum hose to glue on the bracket.

That pop I heard was actually a spark!