Hi all!

I have a 1983 Bronco XLT with a slightly modified 351 (Crane cam, Edelbrock intake, bored and balanced) and four speed manual. Recently it has displayed some unusual electrical problems when the weather gets cold. I live in Boulder, Colorado where the winter temperature frequently gets below 15-20 degrees. When it does, the truck still starts and runs fine, but it takes 5-10 minutes of running at highway speed until the fan motor and turn signals start to work!!! I can feel warm air coming out from the dash vents as soon as the engine gets warm, but there is no fan pushing it. Likewise, the hazard lights work fine but the turn signals don't. Then, all of a sudden, after 5-10 minutes of driving, both the fan and signals start working at the same time!! Go figure!

I've been thinking of trying to call into the Car Guys on NPR, but thought I would try here first. Any suggestions? Thanks!

 

try jumping a hot wire to the blower motor when it is cold to see if it runs. you may have a wire in the harness somewhere that is corroding and has a break in it. when it warms up, the wire expands a little and makes contact.
i know this sounds far fetched, but on my 85 f150, i had an intermittent electrical problem with lights , wipers and a;few other things. i finally traced it to a connection on the hot battery cable that branches off and feeds up under the firewall. it was corroded but when i squeezed it, the items would operate.
the tape covering it had worked loose and let water in, which caused the copper to oxidize. there was green powder in the whole area around the splice. i cleaned it up, soldered it , retaped it and have not had a problem since.

 

Thanks for the information! I'll give it a shot. If that turns out to be the problem, do you think it would be okay to just install new hot leads and leave the old one in the harness? Or should I track down the offending wires and remove them?

 

ALot of these 80's fords have ignition key problems. If you
still haven't found the problem try wiggling the ignition
key a little bit when you have the problem. When it's real
cold the spring for the keyswitch doesn't seem to have enough
strength to put the key in the correct run position and the
accessories won't work.

 

That makes sense about the ignition, however all the other accessories work fine. Just the turn signals and blower motor cause problems?

 

I actually had this same problem in my 81 F-250, and my 82 Bronco. After you start the truck, turn on the heater. If it doesn't come on, rotate the key and ignition back, like a 1/4 of an inch. Heater came on every time.

Good Luck

Murph

 

I had to wait a few days for it to get cold enough here for the problem to appear again (it's been unseasonably warm for the last two weeks). However, last night it happened again, I turned the key 1/4" and everything came on!! Thanks for the help!