OK, I'm back with another problem with my '87 F-250 Bigfoot Cruiser. 460 V8, C6 4WD. I posted previously about it not charging. With all your help I replaced the TWO pigtails at the alternator and got it charging. In the work I was doing tracing wires, etc, sometimes I got a probllem where no juice to the starter. But I was in the middle of working on those pigtails, etc, and the problem would clear up and I'd keep working on the pigtails until I got it done. But now the problem with the starter is there and I'm wondering, maybe I broke a wire (inside the insulation) while I was working on the charging problem. How do I go about diagnosing? Would it be helpful to start by jumping across the starter relay (some people call it the solenoid)? That way would I know if the relay is the culprit, or wouldn't it tell me that? Once I replaced the steering column and ingnition switch, if there was a problem at that end how do I check? In the meantime I'm going to start by checking all wires up around the starter relay to see if jiggling them helps and then check each wire for breaks. It'll be fun to see where they all go! Anyone have any ideas? Thanks.

 

Jump power to the small terminal on the relay, if it cranks you'll know it's not getting power from the switch. Try moving the shifter around while holding the key to crank.

 

My fender mount solenoid was clicking but not passing power to the starter cable.Worked most of the time but I caught it not passing power with my meter.My 96 has a diode from the small coil terminal to ground in side the solenoid.Make sure the new solenoid has this diode. You can check for the presence of the diode in the new part by reversing the ohmeter leads on low range.You will get a slightly different reading .The diode does not show up on the schematic.Its there to protect the computer from inductive voltage spikes.Theres a small flag type terminal on the starter that gets salt damage.Theres a solenoid on the starter along with the fender mounted solenoid.The original solenoid is marked with a warning to use an oem part, print was hard to read.Make sure the fender mount solenoid is passing power every time.Mine clicked every time but failed to pass power 3 times when I had the meter connected.If the solenoid clicks the ignition circut is ok.Have a helper turn the key while you meter the voltage.Truck was sitting for a long time while I worked on the chassis.I thought at first the engine had seized up or the battery was dead.Wrong, learn something new every day.

 

Thanks for your replies. The problem of no power to starter is happenning right, now, but here's the history: I was working on a "no charging" situation, and was moving a lot of wires around in the process. Sometimes during that process there'd be a problem of no power to the starter. After I replaced the 2nd pigtail, it started and it was charging, but when I came back the next day to actually use the truck, the "no power" problem came back, and that's where I am now. I may have moved those wires around a bit when I replaced the sheathing around the bundle of wires. In any event, I'm looking for a "do this first, do this next, do this next, etc" of finding the cause of the no power situation. I was thinking to first check the relay (on the fender) by jumping, to see if it would crank. So as you said, I'd know if it gets power from the switch, or I'd know the relay was bad. Is this right? After that, what? Start checking wires? Which wire?

 

Check the small(14-16?) guage wire to the relay on the starter. My wire wore through a little bit, and wouldn't carry the load all the time. After that, check both relays, then the brushes.

 

Thanks for your replies. There are THREE terminals on the fender-wall-mounted relay (solenoid): 2 big ones on either side, and one small one in the middle that has the push-connector on it. I removed the push connector in the middle and jumped from the battery to it and the starter cranks. So I figure it's either a bad wire from the ignition switch or a bad relay/solenoid. Then I jumped across the two BIG posts on the relay/solenoid. The starter cranks, but extremely slow -- to the point of not turning the engine at all. I hope I didn't burn out the starter by doing this because I left it connect for several seconds. I'll double-check the first test to make sure the starter is still healthy. But what does this test show? Bad relay/solenoid?

 

BTW, when you go to NAPA and ask for a relay, you DON'T get the part that's mounted on the fender well next to the battery. So I guess you need to call it the solenoid.

 

Check your neutral safety switch (or clutch interlock)
Check that your ignition actuator is fully depressing the switch on the lower column.
If these check out then you must find the break in the little red & blue wire.

 

Thanks for the tips. I'll do those ASAP. Great fun. LOL I'll just run a new wire parallel to the red/blue one. After all, it is a 1987 and probly the copper is kinda brittle by now.

 

The wiring in my '87 hasn't been a problem...

 

No need to run wires to bypass things, it just causes trouble down the road. Get a test light or DVOM and trace the circuit. Do you have a MT or AT?

 

Bashby, it is an AT. Jostling the shifter while trying to crank had no effect. I'll replace the fender-well-mounted solenoid and see if that does the trick. After that I'll check the blue/red wire with a VM. After that I'll keep trying all the other fun things suggested. I'm trying to do the easiest things first. I might spend a little more money, but maybe I'll get a lucky hit and be done with it. I got my fingers, toes and wifey's legs crossed until I get it fixed.

 

Easy to check the solenoid.
jump the from small pin to the battery cable side of the solenoid.
It will crank unless the solenoid is shot.

More often, the solenoid fails by getting stuck on.
When the contacts inside weld themselves together
I think Chris has a good photograph of the innards of a failed solenoid...

 

That tells us the relay is good. You are not getting power to the small terminal from the ignition switch. When you turn the key to crank, the ignition switch should send power to the red wire with the blue stripe. It goes from there to the park nuetral switch on the trans, then through that to the solenoid. If you use a test light you can check that wire at those locations to see if it gets power.

 

Thanks Bashby. I got a new solenoid and here's what happens: sometimes everything works just fine -- the engine actually starts and the starter works as normal. Other times the engine cranks and the engine starts but the starter keeps on cranking away. I think the "new" solenoid must be a bad one. I'm going to take it back and trade it on a different one. So based on what you've said, the problem must actually be the wire from the switch is bad somewhere. So probly I'll just run a new wire parallel to the original and not bother trying to find the bad spot. I want to get the new push connector though. Where to get something like that?