Electrical Gremlins Attack!
 

'77 Can Am / Lemans Sport, frame-off restoration when purchased, always performed flawlessly .... until yesterday.

I went out to go for a drive and it wouldn't start. Just a click the first try, then nothing. I checked the battery, full charge. I tried to jump it, but still only a click.

Then I noticed some odd things happening with the electrical system. Lots of weird stuff, this is some of what's happening......

When I get in the car, the clock is running and the interior lights come on. When I activate any of the functions not running through the ignition key (headlight switch, horn button, power lock button, depress the brake pedal), these functions do not work, while the clock stops and the interior lights go out for as long as the switches/buttons are on. When these switches/buttons are released, the clock runs backwards for about 5 seconds, then starts running correctly, while the interior lights slowly come back on.

If I turn the ignition to ACC, the radio comes on and the clock and interior lights continue working, but any of the previously mentioned switches still stop them.

If the ignition is turned to RUN, the clock and interior lights stop again. The radio and AC/heater fan both work intermittently. The turn signals operate, but very slowly.

There are additional quirks I could mention, but I hope this gives the general idea.....

I am an R&R guy and can install most any system. But, electrical diagnosis is by no means my strong suit. I'm really hoping someone here has electical system experience and can suggest where the problem could be. I welcome any discussion of where to start troubleshooting this.

Thanks!

How did you check the battery? Sounds like a bad one

Would a bad battery cause these kind of weird electrical issues? I charged the battery until full, then also jumped it from my truck, but neither worked.

A battery would sure be a cheap and easy fix, just like to be confident of the solution, before buying things I may not need.

Thanks!

Battery could have a cell going away.

I'd check for bad grounds. Battery cable at battery, and at the engine connection. Ground straps at back of engine to firewall, etc.

See if someone has a battery to loan you to see what it does?

:)

Sounds like bad ground to me also.

Battery cables can look good, but when you disconnect them there's corrosion on the inside and against the battery posts. Disconnect both cables and make sure they are clean and shiny inside and out.

This is absolutely true! My mom bought an '85 Thunderbird. It was only about six months old and wouldn't start. I barely saw some white powder around the
end of the insulation. Cut it back and the whole inside was loaded with corrosion!

Side post worse than top post with the crud that grows inside the rubber boots.

Bolts would test good and the cable itself not have anything.

Clay

Update; Problem solved, just a bad battery. File this under "rookie mistakes"! When the battery showed fully charged, I went looking for problems elsewhere. After reading the comments here, I pulled my receipts and saw the battery was 11 years old. Based on that, I purchased a new one. BOOM, car fired right up, problem solved!

Reminder to start with the basics, before jumping too far ahead......

Thanks to the members who commented on my post! I'll leave this thread on the forum, so it can maybe help someone else down the line........