Wasn't there a similar thread a month or so ago? Think it came back to the way they were wired up

 

Yeah, I don't make the rules ha ha.

But I be seein' things, we can observe, notice all the problems with older headlight switches?

Excess resistance in other parts of the circuit cause it to heat up, correct? Not sure on the mechanism on this. But we can see that it trips the circuit breaker. As soon as we clean up neglected grounds and connections the problem is usually remedied, if the switch itself hasn't been physically damaged. That's why I surmised a similar effect is happening with starter relays (solenoids), they are getting roasted. Older NOS and NORS are beefier and probably aren't as quick to fry.

Don't let batteries get run down, keep them charged 100% at all times, don't let grounds and connections become neglected. Just cracking them loose is often enough to get things going again. If they are not clean bright shiny tight, they are not optimal.

Don't grind on a starter more than a couple seconds. Give it several minutes rest between attempts. If the engine won't start immediately, something else is going on and needs fixed. Starters and solenoids are not duty rated on a continuous basis. Ignorance of this has made many a boat payment over the years.

 

My wag is that resistance creates a hotter arc (spark) just like resistor plug wires or caps.

The contacts 'make' and current flows.
The contacts cool and their molten surfaces fuse.
This is why i tried a diode suppressed relay.

I gave up and went with a pmgr.

 

OK I am at my wits end....I have replaced everything in the starting circuit. Battery, all cables, solenoid(again), starter, I have made sure all grounds are good and clean and I even ran a ground wire from solenoid mount to the negative side of battery and it still sticks. Only thing I haven't changed would be the ignition switch. I don't believe that to be the problem cause if I just tap the solenoid with a screwdriver it quits.

Hey ArdWrknTrk when you went pmgr did it bolt right up. I have a C6 and I assume all pmgr starters are for the E4OD.

 

I don't think it matters E4OD or C6.
The PMGR starters were intended for those later electronic overdrive four speeds.

If you are concerned if it will bolt up you might want to check the 'used on' and 'retrofit' on this page; DB Electrical - Ford Mini Starter Truck Van Mercury 460 engine 3226 SFD0030

 

You never did answer what solenoid brand(s) you have been using. Have you tried a genuine Motorcraft or NAPA premium solenoid yet? There is a major difference in the internal construction. I've cut open failed aftermarket solenoids and compared them to OEM. It's amazing the aftermarket ones worked at all.

 

I have used every kind you can think of except Motorcraft, I went to Ford but they told me it was no longer available. If someone tells me it is there might just be a Ford dealer blown up. Yes I have used the Napa Premium one, actually that is what's on it now.

 

This is what I used... Motorcraft SW1951C - Starter Solenoid | O'Reilly Auto Parts

 

thanks 1986F150six it has been ordered, I'm willing to try anything

 

Did you try the voltage drop tests during engine cranking as described in post #2 at the link provided? Might be interesting to see those figures.

 

+1 on that. Here's my take on the voltage drop test:

https://www.ford-trucks.com/forums/1...w-starter.html

You can skip the part where I explained how the earth cooled, etc., and just go straight to the last few paragraphs where I detail exactly how to hook up the meter.

I'd also strongly suggest running a voltage drop test on the circuit that controls the magnetic coil in the starter relay. This is the circuit through the start contacts of the ignition switch. You mentioned you have NOT changed the ignition switch so that made me curious.

My TheoryDuJour(tm) is excessive voltage drop in that control circuit, most likely caused by pitted contacts in the ignition switch. A reduction in voltage reaching the electromagnet coil will reduce the clamping force at the big contacts handling the heavy starter current. This in turn causes arcing, which tends to partially weld the heavy contacts together. This might explain why percussing the solenoid tends to open the contacts.

So here's one more test to run, in addition to the voltage drop test linked earlier. Do this with the ignition disabled by disconnecting and grounding the center lead at the distributor:

1) Put your meter's (+) lead on (+) battery terminal.

2) Put your meter's (-) lead on the small terminal on the starter relay that comes from the start contacts on the ignition switch. You might have to slightly back off the wire terminal to get your test lead in there, but do leave the terminal connected.

3) Have a helper hold the ignition switch to Start for about 10 seconds. Observe the voltage recorded under load, with the starter engaged. Ignore any reading when the relay isn't energized, as you might see battery voltage then.

4) Ideally you will see less than 0.5 volts. The closer to 0.000 the better. Anything more than 0.5 indicates excessive resistance in the control circuit to the starter relay.

Keep us posted.

 

No I have not done the voltage drop test yet. I do need to get me a tester and check that. I believe I can eliminate the ignition switch as one time I had the wire coming from switch disconnected and I had a remote start button hooked up, I was bumping the engine around to install torque converter nuts after engine removal and the solenoid stuck then too. That is why I haven't changed the switch. I will still check voltage drop there though when I get tester hopefully today.

 

Well, the switch still could be the root cause. You're in uncharted waters here, with such a persistent problem even after replacing so many parts.

My hunch is the ignition switch is slowly damaging the replacement starter relays, as described in my previous post. Replace the starter relay, and the new one gets slowly damaged, too.

When the problem returned even while using a remote switch, it could be the starter relay was already damaged by the ignition switch. Can't say for sure, just trying to think of a scenario that would keep burning up replacement relays. The voltage drop test through the ignition switch should help confirm what is going on.

 

well crap, pick up Motorcraft solenoid today and did not pull out f box to check it, was so hot and tired just paid and left. Get home pull out of box and it is the single small terminal one and mine is the double small terminal.... I will say though this Motorcraft solenoid sure feels heavier than the other ones.

kr98664 I am not arguing with you but a new solenoid can stick on the very first try, I am definitely going to do the voltage drop test cause I agree with you there is a unchartered and persistent problem here and I need to cover all bases. I appreciate your help

 

Well, what is connected to the 'I' terminal of your present starter relay?

Is it something you couldn't tie in with the starter cable?
Im pretty sure the little load would not matter.