I'm a new user here, and I've recently purchased a new-to-me 1979 F250 4x4. Being 20+ years away from the farm and working on old work trucks, I'm excited to have a project to dig into with my youngest son. Unfortunately, my biggest source of information/help (Dad) is 2,000 miles away.

My F250 had seldom been driven over the last few years, and once I purchased and started driving, randomly began NOT starting once I turned the key. Just a click. A couple try's later, and it would turn over and start. I determined it was a starter problem (perhaps mistakenly) and decided to replace the starter before I got out in the mountains and it failed completely.

After extracting the rounded starter bolt, and two trips to NAPA for a starter that looked like mine, I installed the new one, and... nothing. Just the clicking of the starter relay on the fender. I can't get it engage the starter and turn over at all.

Truck details:
1979 Ford F250 4x4
1983 460 motor (replaced original 351)
Automatic Transmission (replaced original MT)

The original starter I removed had the attached solenoid. I am 99% sure there was only one cable running from the starter relay on the fender to the solenoid on the fender. I plan to dig around more when I get home from work to confirm.

Voltage across the battery terminals reads 12.4v (somewhat weak)
Voltage from the starter relay to the solenoid when key is turned to crank reads 11.8v.

I've searched everywhere to understand why Ford would have 2 solenoids, and how they should be wired, but I've not really been able to locate anything I can understand.

I'm obviously missing something. There appears to be an "S" terminal on the attached starter solenoid. I've seen other wiring diagrams from Summit Racing that shows routing a cable from the battery-in side on the relay to the larger lug on the starter solenoid, and routing another wire from the starter side of the fender relay down to the "S" terminal. Will this get my starter to engage and turn over?

Sorry about being so long winded. I'll be more brief in the future!

Thanks!
Dean

 

If you indeed have a "S" terminal on the starter, hook a wire to it and run it up and hook it to the large terminal on the fender solenoid that runs to the starter. See if it turns over. If it works, you can run a very short wire from the "S" terminal right over to the large terminal on the starter, it would be the same thing electrically.

Ford always used the fender solenoid, and then they started using the starter mounted solenoid type starters, but kept the fender solenoid also. It eases the load on the ignition switch circuit, and it's always been the spot where Ford taps into the wiring for battery power to power the truck.

 

Thanks Dave for your help. Prior to your reply, I decided to go ahead and try moving the cable from the relay to the starter over to the battery "in" side of the relay (I guess this now provides battery direct to the larger terminal on the starter solenoid). I then added a #12 wire from the relay "out" post down to the starter solenoid "S" terminal. I then crossed my fingers... and it fired right up when I turned the key!

I presume the previous owner had done what you suggested, jumping from the "S" terminal over to the large post on the solenoid.

My next question, will my current routing cause problems for me down the road? Since I now have both wires to the starter located up on the fender relay, it would be easy enough to put them both on the same terminal if my current routing will cause issues.

Thanks again!
Dean

 

Should work ok the way you have it. It's probably best the way you have it, the starter motor does not get power till the solenoid slides the gear out to the flywheel. Once it's out there it makes connection to the large wire and starts turning motor inside the starter.