89 F-350 plow truck woes

yomax4 · Oct 31, 2013

Howdy all. It's been so long since I had this type of issue I was hoping for more brain power. Here's what I got. Plow truck would not make any noise when I turned the key. Full charged batteries, lights work great. I jumped across the solenoid and it started right up. I drove it around a bit to get it loosened up. Tried to start it again. Same deal. I took the old solenoid off and installed a new one. Problem is when I go to hook up the battery wire, the starter runs but does not engage. Is this the instance where I need to hit the newer starter with a hammer to get it to disengage or am I doing something else wrong? New solenoid is no good? Ignition issue? If I remember correctly, it does not matter which side to put the battery terminal on as long as everything else is on the other side. ( I have tried every combination) Also the new solenoid has no S on it but I tried both poles with the ignition wire. The new solenoid has 2 large posts and 2 small ones. The old one had only 1 small post. The instructions said just to use the S post if the system only had 1 small wire. Any mechanical help would be delightfully appreciated..thanks.

john_bud · Oct 31, 2013

Did you use your DVM to verify the signal from the ignition switch was getting to the solenoid? That sounds like the root cause and why the new solenoid isn't working.

On the solenoid, when it's on the fender, the side closest to the battery goes to the battery. The other side goes to the starter. The "s" should be the side closest to the battery. I have never connected one up backwards, so no idea if that will work or not (I'm guessing not, but...)

Zebrafive · Oct 31, 2013

I had the same problem (no start) it turned out to be the starter cable at the solenoid was loose.
I agree with yomax4, first check for signal (small wire from key switch).
Sounds like new solenoid is bad if just hooking it up causes the starter to run.
Why the starter was OK jumping the old solenoid, but only spins with new solenoid is a mystery. Maybe not getting enough voltage?

Dr Dave · Oct 31, 2013

89 fords had a recall on the ignition switch, electrical part would seperate over time and short out, or not work, many fords burnt up from this. If you dont have power to the small selenoid wire, this maybe the cause.

Power comes from the ignition switch, through the nuetral safety, or clutch switch to the small terminal on the fender mount selenoid.

Be sure the selenoid has a good ground to the fender.

Also check the 2 small black ground wire coming from the battery neg. There is a gray connector inline that corrodes.

Dave

yomax4 · Oct 31, 2013

Thanks everyone. I have not tested the small wire coming from the ignition. As soon as I hook up the starter side and touch the battery side, the starter spins but does not engage. I wonder if I have 2 problems here. I did have to start it in neutral for the last year..looks like I may have to have the ignition, neutral safety and solenoid replaced. I found out that only 1 of the small posts ( S ) are used when you have electronic ignition. Aside from the ignition wire. Why would the starter spin when I hook up the wires without the ignition wire hooked up.. Thanks guys.