Need help with electrical gremlin

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Need help with electrical gremlin

August 27, 2009, 10:58:14 AM

I have a weird problem that I'm having a problem diagnosing. I started my Bird and the starter motor continued to crank after releasing the key (which did return to the ON position as normal). I pulled the wire off the S terminal and it still was cranking, so I pulled the negative cable off the battery.
I tested the solenoid for continuity and it was indicatating that the contact was bridging the two studs. So I went and bought a new Ford solenoid ($40) and installed that. Same results, starter continued to crank after the engine was running. I was able to get the solenoid contact freed up by gently tapping on the end of the studs and then I tried putting a test light on the starter output lug (I removed the cable going to the starter) of the solenoid and I cycled the ignition switch through the ON/START cycle several times and the test light indicated everything was working properly. I then reconnected the starter cable to the solenoid, try starting again and same results, starter continues to crank.
Next I pull the starter out and bring it to the local starter/alternator shop and have the guy bench test it and he ended up rebuilding it, new bendix drive etc. I put it back in the car and tested it by putting the ignition to the ON position and jumping from the battery side of the solenoid to the S terminal and the car started and the starter stopped cranking when I removed the jumper. I then reconnect the wire to the S terminal and try starting the car in the normal fashion and the same thing happens again!!!! Something is keeping the solenoid coil energized to the point that the contact welds itself to the two solenoid lugs.
Next up, I borrow a starter and solenoid (both Ford parts) from a 70's vintage car. I remove the starter feed cable (from my installed rebuilt starter) at the starter end and pull back enough cable to reach the borrowed starter whch I have mounted to a board sitting on the floor of the garage. I cycle the ignition switch several times and the borrowed starter cycles fine. OK, now I pull my rebuilt starter out of the car and mount it to the board sitting on the floor and it cycles fine. I put the rebuilt starter back in the car and again, the solenoid gets in the stuck condition. Now I'm getting PO'd. I figure I'll try the old borrowed solenoid even though this is the old style which has two studs, I know which one is the S terminal. Anyway, I put the borrowed solenoid in the car and everything works fine!!!!
I figured the new solenoid was probably the culprit so I go buy another new Ford solenoid (another $40) and put it in. This one does the same thing!!!! I put the borrowed one back in and it works fine.
Any ideas other than using the 35+ year old solenoid?
Thanks,
Rick

Need help with electrical gremlin

Reply #1 – August 27, 2009, 12:02:07 PM

My vote is for the ignition switch, which is not the cylinder where you put the key. The switch is inside the steering column and fairly easy to replace.

Need help with electrical gremlin

Reply #2 – August 27, 2009, 01:14:30 PM

Thanks, I've had that in the back of my mind as I know they can be problematic.
But why does the old style solenoid work correctly? That's what's got me really stumped.
Rick

Need help with electrical gremlin

Reply #3 – August 27, 2009, 01:36:11 PM

Sorry to hear it is happening to someone else. I thought it was just poor NAPA quality parts, since my OE solenoid went out finally a few months ago, resulting in the dreaded click, click sound. Replaced with NAPA premium solenoid, all good for about 2 months, then hit the key one night and it won't stop cranking! Replace solenoid next day with new NAPA premium and worked great, for about a month. Failed on me 220 miles away from home on a Sunday. So I replaced with a new OE Ford "Relay" is what they call it, so far so good, but I may need to look into the switch now that someone has mentioned it.. But if it was the switch, removing the "S" wire from the solenoid should release the contacts as long as they havn't been cranking it over too long and become welded, correct?
On the first solenoid, it was stuck for good once I disconnected power, but the second solenoid, after pulling the starter wire, became unstuck after a minute or so.(I certainly did not try and use it though)
The second time around, I tried disconnecting the start wire first and it did nothing.

Need help with electrical gremlin

Reply #4 – August 27, 2009, 06:00:12 PM

Sorta sounds like your solenoid doesn't have a high enough current rating.
The starter motor will draw more current when turning the engine over than it will mounted to the board.
Do you think your engine is harder to turn over than a stock engine?
Extra high compression maybe.

Need help with electrical gremlin

Reply #5 – August 28, 2009, 09:58:50 AM

Update: I tested the start circuit to see how many amps it would draw to fire the solenoid and if after starting see if the current draw continued or if itwould stop.
With the old borrowed solenoid, it took about 2-2.3 amps to fire the solenoid and the current draw stopped as soon as I released the ignition from START to ON position. So I put in the first "new" solenoid I had and tried the same process. It drew about the same amperage, the car started normal and the solenoid didn't hang up.. I was surprised at this result, so I took the meter out of the circuit and reconnected the wire to the S terminal and now the car starts fine!!!
I'm going to continue to drive it and see if this gremlin returns.
Thanks to everyone who had input.
Rick

Need help with electrical gremlin

Reply #6 – August 28, 2009, 10:32:39 AM

Quote from: softtouch;288546

1. Sorta sounds like your solenoid doesn't have a high enough current rating.
2. The starter motor will draw more current when turning the engine over than it will mounted to the board.
3. Do you think your engine is harder to turn over than a stock engine, extra high compression maybe?

1. This is very possible they make many of those that all look alike but have little differences in amp rating and duty cycle.
2. Yes this is true. Happens more than you would think. The bench tester at work shows a Good Starter but it doesn't work on the car. That is cause the starter on the bench is free spinning. To really test it you need to put a load drive end when it is engaged.
3. Could be and if so get a gear reduction style starter like on the newer cars and trucks.
4. Maybe your starter wire is old and corroded on the inside and needs to be replaced.

Stuckman