'80 F100 Charge Light New Twist
 

Hello All,

My 1980 Ford F100 Charge light comes on during start, then I can turn on any two accessories and it will go off. For example, I turn on the AC/wipers and the light turns off.

I have searched the archives and have and Idea how the light works and that a balance in charges cancels the light itself, and that it may be the Voltage Regulator or Solenoid? I have the Haynes manual so I can get visuals if anyone has any ideas.

It has just started so no daylight to crawl around under the hood, but I have unplugged and sanded the battery posts, followed the heater leads and all obvious wires to see if the were grounded or frayed, and pulled all of the fuses. The battery seems to charge fine, I dont have a tester handy.

Anyone have any leads or experience with this type of charger problem? Suggestions?

Thanks in advance.

I discovered on mine that after turning the key to start it, I have to turn it back a bit and the accessories work and the light goes off. The accessories wont run in my case unless I do turn the key back.

Electrical Contact Cleaner
 

I am an old TV repairman. 35+ years and counting.

My 1983 F-150 has been with me now for about 2 months. I'm having a blast getting it running better and better. One of the first problems was what you describe. I used silicone tuner cleaner and sprayed inside the switch itself, and operated the switch a few times with the battery disconnected. Problem solved.

A little goes a long way.

Best of luck with your Ford.

The return spring on the ignition switch tends to get weak after a while. It's roughly a 20 dollar part(Canadian, less in American dollars) and not to hard to change. You will need to pull the steering wheel off to get at it though. They eventually do give up, the spring is just the first sign.

Just a follow up
 

Thanks for your responses.

I took the alternator in it was all right. Changed the voltage regulator. Charge light still on. Every time I turned on two of the accessories such as the radio and heater, the charge light would turn off, otherwise it was on all of the time.

I wire brushed all of the connections to the solenoid, and as I disconnected the alternator return I noticed black at the end of the inline fusible link. Turns out the link burned out.

You can barely notice if this happens so maybe this will help someone down the line. I just hardwired around it.

The fusable link is less then $2 and I advise putting it back in. The fuse wire was installed for a purpose and can cost more then the two dollars if there is a reason it went to begin with.

Thanks
 

Thanks I will put it back in ASAP. It just had to start on Monday, fuse or not.

Do you know what amperage fuse I need for the alternator return?

I can't find the rating in the Haynes manual but your local jobber will most probably know! I got 2 (1 for a spare) at around $2 CA each