WAG on intermittent issue

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Mister 4x4

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OK - so since I got the car back together, I've experienced an intermittent outage.

The car normally starts up and seems to run fine. Occasionally, after shutting down it will randomly decide not to start. After a [random] period of time, it will then again grace me with its cooperation and start back up as normal.

During the outage, it will crank the starter motor just fine, but not power up the ignition system, run the radio or heater, honk the horn, or energize the 'keyed power side' of new power block (which has the fuel pump, power windows, locks, back-up camera, etc.). I've also noticed that the dome/courtesy lights seem to be fine, but don't recall if the door/key buzzer sounds or not. Headlights, taillights, hazards, and turn-signals aren't affected.

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.'

After the car has sat for a random period of time (typically only a minute or two), the car will usually start and run as normal - with all accessories and systems functioning as normal until the next occurrence.

Another wrinkle: when the guy was driving the car for the safety inspection (run up to 30+ mph, hit the brakes & stop), he noted that the car stumbled and caught itself immediately after testing the brakes - first time that had ever happened.

All of that leads me to believe I have an incidental short or more likely loose connection or wire break somewhere in the ignition switch circuit that controls the main 'keyed power' circuits of the car (aside from the starter motor, that is).

OK - so I need to pick the brains of the electrical gurus and get some ideas where to start my troubleshooting. What I'm thinking so far:

  • ignition switch
  • ignition switch plug
  • ignition switch wiring harness
  • ignition switch ground
  • circuit breaker resetting itself?
  • not a blown fuse (probably not, but the filament could be flopping around inside?)
  • carboned-up connection in the fuse block (cleaned up with new fuses, though)


There are no wrong answers or bad ideas when it comes to tracking down the gremlins, after all.

Unrelated: I installed a new signal switch (which had zero impact of the original issue), and the left side usually keeps flashing even after the switch cancels to center - gotta wiggle it quite a bit to find the sweet spot to get it to quit flashing. Is there something I can bend slighly or trim off a millimeter or so to make it work right?

I have to be honest - I'm getting really close to just pulling the steering column altogether and going with a Flaming River universal set up. But I need to try to fix this at least well enough to trust the car to drive around in-town for a few upcoming car shows before I pull the column.

Thanks in advance!

 

Don C

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I like starting with easy and most visible places. I would start at the solenoid and trace the yellow wire from there to the firewall, looking for any loose connections or a suspicious visible link. Next would be distributor and coil connections. Then I would check the connector on the ignition switch, and while under there give it a shot of WD40 where the rod enters the switch.

 

vozaday

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I had to replace my switch, mind you it was because the starter wouldn't disengage.

 

Mister 4x4

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I had to replace my switch, mind you it was because the starter wouldn't disengage.
Mine's not springing back like it should (which also means my starter can't disengage unless it does), so I'm thinking I'll need to address that issue as well. I'll try the shot of WD-40 first, though (Thanks, Don!).

Replacing that switch might even be the cause of the whole issue - it could easily have gotten some funk in it during the time of getting the car back together - especially after so much time spent at the body shop.

 

73pony

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I would use Houdini over the WD-40. It is a better lubricant and made for lock and lock cylinders. Plus it is less messy and smelly. A little goes a long way though.

 

Mister 4x4

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I would use Houdini over the WD-40. It is a better lubricant and made for lock and lock cylinders. Plus it is less messy and smelly. A little goes a long way though.
Where does one get a can without having to mail-order it? I don't see Lowes, Home Depot, Harbor Fright, auto parts stores, etc., listed - only Amazon, ebay, online locksmith suppliers, et al.

 

73pony

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Do you have a local locksmith shop? They usually have it in stock. I get mine at a small local locksmith in town here.

 

72HCODE

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i would start with the fuse block.

step 1 remove the drivers seat so you can slide under the dash and get a good look at things.

pull the fuses. then on the fuse block in the center is a bolt. pop the bolt and drop the fuse block you will see a large green colored connector. there will be like 50 male pins and female connectors.

shine a light and see if you have dirt corrosion use a brush clean it up really good, use some plastic safe electrical cleaner.

use a pipe cleaner carefully on the female connectors.

put the block back together and clean up the fuse connections with a brush shine them up, clean the fuses and put it all back, and try to recreate the problem.

if no change i would replace the ignition switch to rule it out.

recreate the problem. when you cannot start the motor have somebody in the car turn it over while you check for spark.

now from there things will get more involved. you have an electrical issue that is showing up when things are hot so there is a bad connection somewhere.

with all the other electrical issues horn, radio,etc, but not headlights it makes me go to the fuse block first to clean things out and inspect.

in the green fuse block connector i would look for obvious signs of heat damage on one of the connectors, melted discolored.

for example on my car i found a factory connector crimp that was really deteriorated the connector had melted and the metal was carbonized and the crimp looked terrible. i ended up cutting it off, re-crimping and then i silver soldered the connector to the wire to eliminate an air gap causing arcing or bad connection.

 

Mister 4x4

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Good stuff, Dan - Thank you! ::thumb::

When the car won't start (but will crank), all of the things mentioned above won't work, until the car just decides to start working again - then it's all back to functioning like normal.

That's why I'm thinking along the same lines as you with the issue being related to a specific circuit (or connector or component) that is upstream of the accessories and ignition system. I'm thinking I have either a bad ignition switch or a connection that's otherwise good, but might lose connectivity from heat or a physical disturbance.

The 'spring-back' issue from 'Start' to 'Run' already has me looking at the ignition switch itself, anyway.

 

72HCODE

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it could also be a bad ground behind the dash. midlife would know more then me about how many of them there are. there is one ground connection from the drivers foot well area behind the dash. when running for a while it could be getting hot and it stops conducting to ground.

 

Mister 4x4

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I forgot to mention that the way I normally 'discover' the condition is usually when I open the door and the buzzer's not working (with the key inserted), so I hit the horn and no beep. When I turn the car to 'On,' the radio won't come on. But then when I try to start the car, it'll usually cure the condition and everything's fine again. Occasionally, it won't start and those items will continue to not function as well - usually, after some time, it'll crank and fire with no issues and everything's fine.

During the car inspection, I thought the horn button had quit, so I checked connections there (took the wheel off, and everything). No luck, so I decided to take it home. The inspector said he had to back the car out of the stall (for liability purposes) and it initially wouldn't start for him. Then he turned the whole thing back to 'Off,' then back to 'On' and I heard the fuel pump - which the car started up right after that, along with the radio, the horn, etc., working fine. Drove it home with no issues.

That had me initially thinking "new ignition switch," but I have no issues checking and cleaning the fuse block system - just in case.

 

Mister 4x4

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it could also be a bad ground behind the dash. midlife would know more then me about how many of them there are. there is one ground connection from the drivers foot well area behind the dash. when running for a while it could be getting hot and it stops conducting to ground.
Hmmm... I don't remember hooking up a harness ground specifically in the driver's foot well area. It's been a few years, though. ;)

 

Mister 4x4

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That sounds like a fusible link that has been spliced poorly or is just blown, but is still making contact
Interesting, and sounds totally plausible. ::thumb::

I'll have to grab the Electrical Assembly Manual back out of its hibernation. :cool:

 

midlife

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I forgot to mention that the way I normally 'discover' the condition is usually when I open the door and the buzzer's not working (with the key inserted), so I hit the horn and no beep. When I turn the car to 'On,' the radio won't come on. But then when I try to start the car, it'll usually cure the condition and everything's fine again. Occasionally, it won't start and those items will continue to not function as well - usually, after some time, it'll crank and fire with no issues and everything's fine.

During the car inspection, I thought the horn button had quit, so I checked connections there (took the wheel off, and everything). No luck, so I decided to take it home. The inspector said he had to back the car out of the stall (for liability purposes) and it initially wouldn't start for him. Then he turned the whole thing back to 'Off,' then back to 'On' and I heard the fuel pump - which the car started up right after that, along with the radio, the horn, etc., working fine. Drove it home with no issues.

That had me initially thinking "new ignition switch," but I have no issues checking and cleaning the fuse block system - just in case.
Classic symptoms of no battery power (intermittent) at the ignition switch or at the switch connector. That's where I would start. If all good and problems are still occurring, I'd look carefully at your connections at the battery post and the starter solenoid, along with the battery cables.

72HCode's advice is good, but to tell you the truth, I've found almost no examples of corrosion at the back of the fuse block where the multipin connectors mate (watch out...mini-connectors are the result unless they use contraceptives rofl). If there is a problem there, it usually is a catastrophic failure due to burned wires/shorting and then nothing will work.

 

Don C

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I decided to look at the wiring diagram instead of WAGing. A single yellow wire feeds all of the functions in the switch. So, because you have start power, the main feed is good, and the problem has to be in the switch contacts, the connector, or between the switch and the coil. Because your switch is "sticky" the contacts may be gummed up. I would check connections at the coil and distributor and at both ends of the pink resistor wire. If it has over heated it may have damaged the connections.

Do you have the factory tach? If so, that's another possibility. You can unplug the tach connector and jump it, to eliminate the tach as a problem.

 
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Mister 4x4

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Nope - no factory tach... it has a 'clock/speedo' cluster, in fact.

OK - so I'll be checking the solenoid connections (which should be good since it's all new, but you never know), and focus on the ignition switch. If all that's good, then I'll scrutinize the fuse block.

Thanks guys - you're the best! ::thumb::

 

Don C

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The run wire (red/light green) does not go through the fuse block. The pink resistor wire connects after the ignition switch, then changes to red/light green, goes through the firewall connector, through a 3-pole connector and on to the coil.

 
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