So, Baby Blue has an electrical demon. On her first long drive after setting for a bit, of course!

Out of the gate; no brake lights.
100 miles out dash lights **** the bed.
200 miles out speedometer gave up the ghost.
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At home; I checked all bulbs. They "look good".

Do I just chalk it up to wear and tear? Pull all fuses; hose the fuse box with electronics cleaner and replace with known new fuses. I do have them on hand. I am also thinking of replacing the brake light plunger above the brake pedal. (I forget the correct term). The trailer brake assembly under the dash does not light up either; when brake is applied.

Dash lights could also be bulbs...I haven't tore into that yet.

A speedometer cable could also be needed.

Since, this is a emotional rebuild for me...I want to do it right.

If anyone can give me the procedure for testing electrical Demons I would be glad for the info. I have a test light and a multimeter.

 

The speedometer is totally mechanical, so no electrical probs there. Mine didn't work when I got my truck, but it was because the cable wasn't pushed all the way into the speedo head.

Had you had the instrument cluster out soon before the problems cropped up?

Couple questions about the dash lights: Are your heater controls still lighting up? What about the indicators for the headlight and wiper switches?
If all dash lights are out, it could be a fuse, or the light switch, or a wiring problem. Are the gauges and warning lights (brakes, seatbelts) working? If they are also inoperative, perhaps the wiring harness connector has pulled out of the cluster back.
If only the gauge lights are inoperative, then the problem could be the the cluster back disintegrating and causing a loss of contact where the bulbs go in.

The brake lights might be the brake light switch, but could also be because of the turn signal switch - the brake light circuit passes through the TS switch.


First thing to check would be fuses - and make sure that the fuses are actually passing current - they could be unblown, but if the contacts are dirty or corroded, that could impede the current.
Next I would check the bulbs, although it seems unlikely that they would all go at once.
The best diagnostic technique would be to to test the appropriate feed wires to see if they are live when they should be.

 

I have not pulled the instrument panel yet. It's on my to do list to check for loose fittings. I do not know if the other lights work; hubby drove her home with no heater core. So, that along with blower motor...since I have the shroud/ assembly out; are first to fix to make her road worthy. Brake lights are second. Other electrical third.

Thank you for your input on where to go, and what to look for. I just didn't want to *****-nilly replace everything hoping for an exorcism. Haha bulbs and fuses are cheap. But cents turn into dollars in a big hurry. Especially, since my loooooong term goal is to fully restore Baby Blue to original ( or as close to it as possible) as a homage to Grandma.