WAG on intermittent issue

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Mister 4x4

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Do you have a circuit breaker in the system somewhere?
Yes. There was an old rusty breaker between the battery and the bundle of wires below the starter solenoid. I replaced it with a new 30 amp breaker when I started putting it back together.

 

Mister 4x4

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So, a new development: I had the car on the charger, fired it up, backed it out, worked on a few things today (plates, trunk stripe, etc.) and went to pull the car back in when it started getting dark, and poof - turned the key... nothing. No starter, fuel pump, no dome lights, no radio, no nothing. Whipped out the DVM and started checking things. Battery = good. Ground = good. Positive side of the starter solenoid = good. Circuit breaker = good.

Scratched my head, and decided to tap on the top of the solenoid with the butt of a big screwdriver. Voila! Open the door, dome lights. Put in the key, buzzer. Turn the key, fuel pump runs and the car fired right up.

So, I'll be getting a new solenoid tomorrow before I replace the ignition switch (needs it anyway because the key doesn't spring back) and adjust the TV cable (about 1/4" of cable showing out the end of the adjuster = low pressure and early shift points).

This bugs me because it's a 'new' solenoid... and the second one I've bought for the car (the first wouldn't even work out of the box).

But like my pal Jim always says regarding parts, "New only means 'new,' it doesn't necessarily mean 'good.'" (He was a parts guy at NAPA when I met him)

 
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I'm not sure it's the solenoid, as all of the power connections are on the post on the battery side of the solenoid (or the terminal block if you have factory gauges), the only power circuits on the other side are the starter, and the "I" terminal. Tapping on the solenoid shouldn't have any effect unless the nut on that post is loose.

 

midlife

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There is one connection that is hidden on the starter solenoid: the ground via the mounting plate and bolts. Tapping on it may change the position such that it now has a good ground.

 

Mister 4x4

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There is one connection that is hidden on the starter solenoid: the ground via the mounting plate and bolts. Tapping on it may change the position such that it now has a good ground.
Thanks! I will ensure there are no obstructive substances (like Rust Bullet, etc.) in that immediate area. Still going to get a new one, and some dielectric grease, too.

 

Mister 4x4

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Good idea - I'll do that next time I get under there for more 'clean-up' efforts. I'm going to move those things around so it looks a little more 'factory' and clean up the wiring when I install the H4 harness and add a 40A breaker for the accessories while keeping the 'essentials' on the [standard] 30A breaker. I'll be relocating the bait box/fuse block lower where the voltage regulator is now for better aesthetics.

So, I got the dielectric grease, and also some of those 'ninja star-looking' lock washers. I sanded away the Rust Bullet from the mounting surface, added some of the star washers with some dielectric grease, and re-mounted the solenoid. So far, so good.

Still need to replace the ignition switch, as I got focused on adjusting the TV cable and ran out of daylight.

 

midlife

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Still need to replace the ignition switch, as I got focused on adjusting the TV cable and ran out of daylight.
Did you run out of quarters for the daylight machine?

 

piper62j

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The physical ignition key switch itself seems sluggish, as in, doesn't spring back from 'Start' to 'Run' like you would hope a newly rebuilt column with a new ignition switch would. Turn the switch to 'Start,' the car fires [usually], then you have to "help" turn it back to 'Run' so the starter motor shuts off. There is also a little bit of searching that needs to happen between 'Run,' 'Off,' and 'Accessories.'

Suggestion.. there is a rod which connects the lock cylinder rack down to the ignition switch.. The switch end of the rod must be pointing upward at that end. If the rod is pointing downward, it will bind along the steering column outer housing and will not allow the lock cylinder to return to the start position freely.. Re-adjust the ignition switch and tighten the bolt.

It's happened to me twice over the years.

 

Mister 4x4

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OK - so, an update. ::thumb::

Last week's re-grounding of the starter solenoid seems to have helped immensely. I didn't have nearly as much difficulty starting the car without assistance - it just fired right up Friday evening when I backed it out to replace the ignition switch.

I got it into the carport area, removed the steering wheel, and dropped the column. The 'old' switch came off without difficulty, and the internal spring was completely shot - no spring-back capability whatsoever. While I had it apart, I checked the key cylinder and rod for smooth, unobstructed function - everything was great (and the rod end was pointing up, as it should be... thanks for the reminder, though ::thumb:: ).

Installed the new switch, checked functionality, and zip-tied the extra cabling to the steering column to ensure nothing got caught up with the brake pedal. Put it all back together, hooked the battery back up, and it fired right up just like it's supposed to, with the key popping back to 'On' and everything.

Even more 'update' information: I actually drove the car yesterday to the Rec Camp Car Show, and everything worked perfectly - no intermittent electrical issues or ignition switch failures.

So, I'm calling this one "So Far, So Good." ::thumb::

Thanks for all your help, guys. Once again, top-shelf information and advice!

 

Hemikiller

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Had a similar problem on my first sportsroof after swapping to a 4-speed from an auto. Intermittent crank but no-start, fouled plugs etc.

Turned out it was a missing negative battery cable to chassis ground connection. With the auto in place, the coolant lines were acting as the engine to chassis ground ... :/

The factory method was a tab mid-cable that was captured by one of the voltage regulator screws - not so good after 40 years. Also, few of the aftermarket cables came with that lug in place and a not-so-sharp owner wouldn't think twice about it.

On my current 71 Mach, I welded a stud into the fender apron to act as a chassis grounding point - no more ground issues for me!

 
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interesting thread. I am going through a similar issue right now, but in my case the starter won't crank and all of my switched power seems to be gone. However, the non-switched devices such as headlamps and dome light would work. After a few minutes all comes back to normal. This happened twice after starting the engine three times in a short period of time - because the engine will stall when going into reverse.

 

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