"Starting" to pull my hair out

[sapperstang45]

Ok here's my issue. The other day out of the blue my starter stayed engaged after I started my 93 GT. I replaced the solenoid and my ignition switch and checked all my wiring so far. What I don't understand is that it only does it when I use the key to start the car and even then it only does it if I stay on the starter for longer that 3 or 4 seconds. If I bump it and get lucky enough to get it to fire up its fine. It also works fine if I just turn the key to the run position and jump the solenoid. I talked to one of my friends who was into racing and who is familiar with the 5.0 mustang and he said that the bendix on my starter may be damaged. But I can't understand why it doesn't do it when I jump the solenoid. I've been on here and read every post concerning the solenoid and ignition switches and tried everything they suggested and that I could think of. Also I took the old solenoid and ignition switch apart and they both looked fine. No corrosion or welded contacts or anything. Any help on this would save me a lot of stress and hair loss.

 

[Darkwriter77]

When you say "ignition switch," are you referring to the lock & tumbler mechanism (the part the key goes into), or the actual electrical switch component on the column (the part that the lock & tumbler moves back and forth, with the giant rectangular plug on it)? Just have to ask, as sometimes folks get the two mixed up. Still sounds like an ignition switch issue to me - a defective part, perhaps?

Have you already cleaned and checked all of your major grounds and cables for corrosion, wear-through, or other signs of damage? The ground from the intake to the firewall and the cable from teh block to the common ground near the ignition coil, and the primary cable from the solenoid to the starter would be the first places to look.

 

[sapperstang45]

By the ignition switch I refer to the electrical part. Also the wiring to and from the solenoid are good to go. I also put a test light on the trigger wire coming to the solenoid from the ignition and tested it to see if current was still running through it after the key was turned from the start to the run position. It checked out good to go as well.

 

[Darkwriter77]

You're right in that the starter bendix has nothing to do with the issue you're describing. If turning the key to "RUN" and jumping the solenoid works fine, then you've eliminated the starter, itself, as a possible issue, and you've also thus verified that the ignition switch is good as far as telling the rest of the system it's okay to go ... although it's still possible that the switch could be defective or otherwise not giving signal to the fender solenoid in the "CRANK" position. So, the issue has something to do with either the fender solenoid, itself, the ignition switch (defective?), or the wire running between the ignition switch and the fender solenoid - the wire that simply gives a signal to the starter solenoid when to start and stop supplying current to the starter circuit.

Jumping across those posts is basically the same as bypassing the solenoid and pretending it's not there at all - you're just momentarily completing the connection between a constant-on post (the battery side) and a momentary-on post (the starter side). Since this is a '93 we're talking about, you ARE running one of those "mini" style starters, right? Because unless they wire them differently from the factory than they do when you retrofit one onto an older Fox, the only thing that should be on the post (momentary-on) that's opposite from the battery side is a thin wire running down to the solenoid on the starter - all that's doing is telling the starter, "Okay, we've got juice, start turning," and then shutting it off once the current is stopped, because the fat cable where the starter draws its high-amp current from is on the battery side (constant-on).

 

[sapperstang45]

Jumping across those posts is basically the same as bypassing the solenoid and pretending it's not there at all - you're just momentarily completing the connection between a constant-on post (the battery side) and a momentary-on post (the starter side). Since this is a '93 we're talking about, you ARE running one of those "mini" style starters, right? Because unless they wire them differently from the factory than they do when you retrofit one onto an older Fox, the only thing that should be on the post (momentary-on) that's opposite from the battery side is a thin wire running down to the solenoid on the starter - all that's doing is telling the starter, "Okay, we've got juice, start turning," and then shutting it off once the current is stopped, because the fat cable where the starter draws its high-amp current from is on the battery side (constant-on).

I think you just solved my problem. I have my wires backwards on the solenoid from what you are describing. I have the "on-starter" solenoid wire on the battery side of the fender solenoid and everything else on the firewall side. To me that says that since its backwards the starter can't kick out because the juice to the starter through the thick wire doesn't stop coming when I turn the key back. Ill try that and let you know how it turns out.

 

[sapperstang45]

Well I checked the fender mounted solenoid and sure enough I had the wires backwards. I switched them and it still had the same result. On a whim, I put both wires running to the starter on the m side and everything else on the opposite post. I tried it and it started and the starter kicked out no problem. But everything I've read or been told said that only the small wire to the starter goes on that post. Will this hurt my system?

 

[Darkwriter77]

Shouldn't hurt anything, I don't imagine, as it's not going to see constant voltage either way - you won't burn anything up.

I guess they must have things a little different on the 93's from the factory than the retrofitted setups. The two-solenoid setup always seemed kinda redundant to me - having one on the fender and one on the starter, itself - but I suppose Ford had a reason for doing it, since they wouldn't have spent the extra buck or two it cost to keep both solenoids on there if they didn't need to. Maybe it was just a short-term thing they did until the SN95's came along where they started using a power distribution block, instead of stacking wires with loop connectors to everything all on top of one post. Maybe JRichker can shed some light on the specifics of it...

Anyway, good to hear you got it working right.

 

[sapperstang45]

I thank you for all the help. I drove it to work today and everything seemed fine. Its charging a little low but that's due to the underdrive pulleys. Its nothing that I'm concerned with. Thanks again!

 

[Darkwriter77]