I have a 1987 D100 that won't start with the key, you can turn the key the accessory and on, it reacts as expected. when you attempt to start it there isn't even a click under the hood. When the key is in the on position it is possible to start it using a screwdriver between the bolts on the starter. The fuse appears to be good and I would like to check the starter solenoid but I am not sure where it is, it does not look like it is attached to the starter but I only looked from the top, where is is located? Does anyone have any suggestions on other items that may be the problem?

 

The solenoid is the part on the starter where you used the screwdriver to start it.

Does your truck have tilt steering?

Is your key ring large and heavy?

It's possible to wear the key cylinder out, and also the rod/switch on the steering column.

Sometimes the key cylinder wears out enough that it will not activate the rod far enough to crank the engine.

Look under the dash, you should be able to find the actuator rod along the steering column, it goes to a switch.

Try turning the key and watch the rod, see how far it goes.

You may even be able to push the rod some as you turn the key to 'start'


If that's not it, then you have an electrical gremlin between that switch on the steering column, and the starter solenoid.

 

Sorry for the delayed reply, I am away a lot for work. So it sounds like it is not the solenoid as I am able to start it. The truck does not have tilt steering and the key ring is not heavy, that being said I just got the truck and it had this issue so I can't speak for the previous owners. I looked under the dash but did not see a rod, the steering column also appears to have a steel cage over is so I am unable to take a close look at it.

 

I did a bit more testing:

The large brown wire on the starter relay goes to the solenoid, if i put 12v through it the starter will crank so from the relay to the starter is good.

There is a large red wire going to the starter relay and it has 12v going to it constantly, likely the supply wire from the battery.

There is a large yellow wire and a small yellow wire with a black line, neither of these show 12v even when attempting to start the truck with the key.

As you said HillBillE it looks like it is likely in the switch in the steering column, however, I am unable to find a was to take it apart. I took the trim off around the gauges but it looks like everything is up further in the steering column. Do you happen to know how to take this apart?

I did find this online, http://www.justanswer.com/dodge/5fpy...d-stopped.html, but it does not appear to be the same setup as mine.

 

I am able to start the truck by jumping the red and yellow wire in the ignition wiring harness within the cab, it is certainly the switch but I am still having trouble disassembling the steering column. I attached a picture of where I am at, any suggestions?

 

Look at the bottom of the steering column, near the pedals, there should be a switch with a rod attached to it that goes up to the key cylinder, you can try cranking it and see if the rod is actuating the switch down there. If it is, most likely the switch is bad, there should be slots in the mounting for adjustment if needed though.