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For those that haven’t seen my resto thread, I am in the homestretch of a frame off on my ‘70 W-31. Yesterday we tried to fire it up. as a side note, the engine has been broken in on the dyno and has been tuned.
With 5 gallons of C12 racing fuel in the tank, we started our process to crank the car over until we encountered a strange electrical issue.
Cranked the car a few times just to get things moving since the engine hasn’t been run in a year and a half. First time, it cranked for a second or two after I turned the ignition off. Strange. Turned the key a second time, and it did the same thing where it tried cranking for just a split second longer after I shut it off.
Then we started cranking for real, and it was much more responsive when I stopped trying to crank. Stuck solenoid? Unfortunately, then the battery died (too many nights of testing bulbs). Battery charged. Put the cables back on the battery, and with the ignition off and the key on the floor, it started trying to crank! What the hell!?
We double checked that the purple and yellow wires weren’t touching the positive battery cable. We pulled the purple wire and hooked it up to the volt meter which showed zero, but that was after we put the cables back on and hadn’t tried cranking it again.
Could it be the solenoid? Ignition switch? I’m going to drop the starter so I can get a better look.
The starter is a numbers matching dated piece that was allegedly rebuilt by the shop I bought it from off eBay so it’s possible the starter needs to be gone through. No idea on how old the solenoid is. Battery is a repop R59 (battery inside a battery), and the ignition switch is original to the column which has been rebuilt by our friend Patton.
I suspect a stuck solenoid. The pole piece that slides in the solenoid (and the tube in the solenoid that it slides in) can rust, causing it to hang up.
I've also experienced a really oddball version of this, where there was a burr on the armature shaft where the starter drive slides. The force of the ring gear backdriving the starter drive was just enough to cause it to hang up on this burr in the extended position. Of course, that holds the pole piece in the retracted position, which holds the contact disc against the terminals in the solenoid.
I suspect a stuck solenoid. The pole piece that slides in the solenoid (and the tube in the solenoid that it slides in) can rust, causing it to hang up.
I've also experienced a really oddball version of this, where there was a burr on the armature shaft where the starter drive slides. The force of the ring gear backdriving the starter drive was just enough to cause it to hang up on this burr in the extended position. Of course, that holds the pole piece in the retracted position, which holds the contact disc against the terminals in the solenoid.
The solenoid theory makes the most sense. When I just hit the ignition the first two times, it cranked a little longer but that was also the first time the starter and solenoid were activated in over 3+ years. When I went to hard cranking it, the issue went away in terms of it trying to crank after the ignition returned to the run position. I was going to stop at Napa or O'Reily's and pickup a "new" starter to at least rule out that the starter / solenoid is the culprit. If it isn't, what on the ignition could it be? Perhaps the actuator rod is getting hung up?
The solenoid theory makes the most sense. When I just hit the ignition the first two times, it cranked a little longer but that was also the first time the starter and solenoid were activated in over 3+ years. When I went to hard cranking it, the issue went away in terms of it trying to crank after the ignition returned to the run position. I was going to stop at Napa or O'Reily's and pickup a "new" starter to at least rule out that the starter / solenoid is the culprit. If it isn't, what on the ignition could it be? Perhaps the actuator rod is getting hung up?
It's possible (but unlikely) that the contact metal in the starter switch has "smeared" from use and combined with a little stickiness in the switch could be maintaining contact after you release the key. The easy way to test that is next time the starter hangs up, turn the key to the OFF position. If the starter continues to crank, it's not the switch.
Wouldn't the fact it was cranking with the ignition off and keys on the floor rule out the ignition switch? This is actually a fairly common failure mode with '90's era Ford ignitions. The solenoid would lock and weld itself in the 'on' position causing the starter to continuously run regardless of key position (ask me how I know). I'd put my money on the solenoid and not necessarily the rebuilt starter.
June 7th, 2021, 06:46 AM
