Fender mounted starter solenoid wiring - is this as messed up as I think it is?

[TWeatherford]

So I went out to fire up the 88 today, and only got a click. As I started troubleshooting, I notice that the wiring on the fender is different than I've ever seen one wired before. It looks to me like that little solenoid is carrying all the load of spinning the starter - so its probably failed (at least it didn't weld the contacts together and fail in the on position ). The solenoid is connected to the battery on with the lead on the right, and the lead on the left goes to the starter. Is this an acceptable way to send power to the starter? Any advice on troubleshooting the solenoid?

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[gandalf]

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We all tend to get a bit creative in out wiring, and I think maybe somebody did on your solenoid. I won't say that it's wrong, but I don't think it's quite right. Does the heavy cable on the left go to your starter? Is that the main power for the starter? If so, that's not right. Do you have power running from the battery positive to the starter? My understanding, and that could easily be wrong, is that the cable on the left hand terminal, the forward terminal, should be the trigger for the starter. That being the case, you shouldn't need such a heavy cable there.

I've put a picture of my starter solenoid above. On the right hand side I have a heavy red cable as power input from the battery positive, a small red cable as power to the electric fuel pump, and a heavy cable, in a wire loom, powering the glowplug controller. The smaller red cable on the left joins the heavy red cable from the battery positive going down toward the starter.

Hope that helps.

 

[TWeatherford]

Is that the main power for the starter? If so, that's not right.

Yes, it is. My 94 is set up just like the picture you posted. All starter power, as far as I can tell, goes through this solenoid. I don't even understand how thats possible, really, as starter solenoids are pretty light duty. I'd think it'd fry the first time it was used, but this one came on the truck when I bought it and has been in use for 4 months by me. I'm thinking the reason its like that might be that the Cummins that the starter is bolted to, originally came from an industrial application, and as far as I can tell there is no starter mounted solenoid. However, nothing else on this engine swap is hacked, it is all first rate work. I don't see why they'd do everything right and then hack this.

 

[cpdenton]

I am not sure it is a hack. This is on your cummins swapped truck right?

This is how most ford gasser starters are wired, because they do not have a starter mounted solenoid just like your cummins starter. On my old f150 and my ranger, they are just like the picture you have. One solenoid on the fender.

Question is this. Is this solenoid strong enough to handle the amperage a diesel starter demands. I would bet no, or they would be like that from the factory. You may have to look in to a heavier aftermarket solenoid rated for a higher amp load than a factory ford solenoid.

 

[icanfixall]

Nice clear pic Ken.. Shows what the Ford solenoid wireing should be. The post of the right carrys full load or its hot at all times. All those wires connected to that side are alos hot at all times too. The push pull wire with the black cover between the two large lugs of the solenoid is the starter ignition wire. Remove that and jump it to the right and the solenoid closes and the engine cranks. Thats where I jump from when I'm bleeding a fuel system or timing a truck. Sure beats getting in and out of the truck to start it. To shut down the engine I lift the fuel shutoff solenoid wire on the injection pump. As for the original poster asking if this first pic was correct and it being about a cummins swap... Don't know but it seems like lots of load going thru that solenoid. Maybe someone that driving a cummins swap will chime in.

 

[TWeatherford]

Well I ended up just cleaning all the contacts and she fired right up. This is on my 88 with a Cummins in it. The truck had a 460 in it from the factory, so its likely the factory solenoid. It certainly seems to have been on there a long time, so I'm inclined to believe it will stay working for a while yet. The battery cables are pretty small for a diesel, they're likely factory for a 460, so maybe they won't carry enough current to overload this solenoid. Even so, the Cummins fires up every time I hit the key. I have to fix enough stuff that is broken to go fixing stuff that isn't broken, so it looks like I'll leave it as is for now. Thanks for the input.

 

[redneckaggie]

hate to tell you but the wire will definately carry enough current to start that truck but the insulation is what you need to worry about. if you overload those cable the insulation wil melt off and you have an electrical fire so check load going to the starter. I know they sell aftermarket solenoids rated for high amperage that will probably be the best idea.

 

[madpogue]

Have you confirmed that there is not a separate wire going to the starter? That would determine whether that _relay_ on the fender is carrying the whole current of the starter.