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Ignintion causing stall while driving...help

Mopars & Missiles said:
You can test the ignition switch very easily through the bulkhead connectors on the engine side of the firewall. You WILL need a DMM and know how to use it. Got one?
Click to expand...
I have two and I know how to use them. I promise I'm not an idiot, this car is two months old to me. Already had to replace the distributor, intake gasket and the entire rear end LSD.
 
wsutard said:
I have two and I know how to use them. I promise I'm not an idiot, this car is two months old to me. Already had to replace the distributor, intake gasket and the entire rear end LSD.
Click to expand...

Never said you were an idiot, but a lot of people don't want to put in the effort, just have someone else fix it for them. You are starting to come along now, so maybe we can find this problem for you. Now I'll have to go out to the garage and get my special schematics that will make this a lot easier. Hold one for awhile.
 
OK, here we go. Remove the engine wiring harness connector from the bulkhead connector under the hood. I think it is the middle connector of the 3.

With the DMM, check continuity between pins "P" and "N". With ignition switch off, it will be open. Turn switch to "Run" position, it should be ZERO ohms or very close to it. Kind of wiggle the key to see if the contacts are intermittent. If this checks OK, on to the next step.

Now check continuity between pins "P" and "Q". This checks the START position and you may need a helper to hold the key in the start position. Again, wiggle the key a bit to check for intermittent contacts. Once again, it should be ZERO ohms or very close. Also while doing this check, you can also check that YELLOW wire that broke at the starter relay. You should have continuity (ZERO or near) between both "P" and "Q" and the Yellow wire.

If all these checks indicate that your Ignition Switch is good, then your problem is the engine wiring harness/connectors. Report back and we can go further if necessary.
 
Uhh, yeah. That doesn't look good.
image.jpeg
 
Interestingly, neither of the spots on that middle bulkhead connector that look messed up are used.
 
Mopars & Missiles said:
OK, here we go. Remove the engine wiring harness connector from the bulkhead connector under the hood. I think it is the middle connector of the 3.

With the DMM, check continuity between pins "P" and "N". With ignition switch off, it will be open. Turn switch to "Run" position, it should be ZERO ohms or very close to it. Kind of wiggle the key to see if the contacts are intermittent. If this checks OK, on to the next step.

Now check continuity between pins "P" and "Q". This checks the START position and you may need a helper to hold the key in the start position. Again, wiggle the key a bit to check for intermittent contacts. Once again, it should be ZERO ohms or very close. Also while doing this check, you can also check that YELLOW wire that broke at the starter relay. You should have continuity (ZERO or near) between both "P" and "Q" and the Yellow wire.

If all these checks indicate that your Ignition Switch is good, then your problem is the engine wiring harness/connectors. Report back and we can go further if necessary.
Click to expand...
Based on the mymopar wiring diagram and tracking where the wires flow in my engine bay, looks like the top set in the picture contain the ignition wires. The middle set, with the messed up connectors, are for cornering lights, blinkers and the windshield washer fluid. The two messed up areas are specific to cornering lights, which I dont have. (not blinkers)

I am having trouble reconciling your statements of testing P N and Q with the wiring diagram and my connectors. How do I tell which is P N or Q? Wiring diagram lists out as colors.
 
I found the test specs for the ballast resistor and coil on mymopar. My ballast is spot on for their recommendations.

My coil is at 1.5 ohm where the recommendation is .75 to .81 ohm on the primary. It also states that a significant deviation signifies the coil is bad.

The plug portion of the coil is spot on at 10,000ohm.

http://www.mymopar.com/index.php?pid=81
 
Ranger16 said:
WOW! Those puppies are in sad shape. My guess is that's where your problem lies. Personally, I think if it where mine, I''d be looking at changing those bulkhead connectors.
Click to expand...
I'm researching that right now. opinions welcome.
 
wsutard said:
Uhh, yeah. That doesn't look good. View attachment 357769
Click to expand...

Classic failure here. The melted connections are "P" and "J". "J" is the battery feed INTO the car to the ammeter. "P" is the feed OUT of the car from the ammeter to the alternator output stud. This is the high current path that over time gets corroded which in turn builds up resistance in the contacts, which as you know, causes HEAT, hence the melted contacts and connectors.

Congratulations, you've found your ignition problem.
 
Last edited:
wsutard said:
Based on the mymopar wiring diagram and tracking where the wires flow in my engine bay, looks like the top set in the picture contain the ignition wires. The middle set, with the messed up connectors, are for cornering lights, blinkers and the windshield washer fluid. The two messed up areas are specific to cornering lights, which I dont have. (not blinkers)

I am having trouble reconciling your statements of testing P N and Q with the wiring diagram and my connectors. How do I tell which is P N or Q? Wiring diagram lists out as colors.
Click to expand...

Again, look at page 8-101 and study the diagram. It is really fairly simple. Smack dab in the bottom center of the page is your BULKHEAD connector with mating connectors shown around it. Look at each connector, it is made so that it only connects to one place and cannot be connected to the others. Each position of each connector has a letter designation assigned to it.
 
Last edited:
wsutard said:
Interestingly, neither of the spots on that middle bulkhead connector that look messed up are used.
Click to expand...

Well, they were used at one point from the factory. I just took a look at your photos again, the one you posted showing the Yellow start wire broken. If you notice the TWO heavy wires in the background with the BUTT connectors on them, THOSE are the "P" and "J" wires that are missing from your bulkhead connector. Someone has changed the wiring and rerouted those two due to the meltdown that you see on the bulkhead. So, we are still chasing your intermittent power problem that is causing your engine to quit on you. Follow those wires and make sure connections are good and tight. The one with the fusible link is the INPUT power "J" and should go to the RED side on the ammeter under the dash. What a mess. (Not your fault, but still a mess).
 
I'm getting to the point where I think a full rewire is needed. Not what I had in mind when I purchased this money pit.

Anyway, I found the electrical diagrams in my Service Manual, they start on page 285 for me. Wow, lots of lines to follow. Since we now know that the wires have been moved around I am going to need to follow the wires back from their end destination to the bulk head to figure out which ones correspond with the switch. I will report back once I have tested the continuity for each setting on the switch. Since I ruled out the ballast the likely next culprit is the switch, followed by the coil (since it gave me weird readings on the ohm test).
 
Mopars & Missiles said:
OK, here we go. Remove the engine wiring harness connector from the bulkhead connector under the hood. I think it is the middle connector of the 3.

With the DMM, check continuity between pins "P" and "N". With ignition switch off, it will be open. Turn switch to "Run" position, it should be ZERO ohms or very close to it. Kind of wiggle the key to see if the contacts are intermittent. If this checks OK, on to the next step.

Now check continuity between pins "P" and "Q". This checks the START position and you may need a helper to hold the key in the start position. Again, wiggle the key a bit to check for intermittent contacts. Once again, it should be ZERO ohms or very close. Also while doing this check, you can also check that YELLOW wire that broke at the starter relay. You should have continuity (ZERO or near) between both "P" and "Q" and the Yellow wire.

If all these checks indicate that your Ignition Switch is good, then your problem is the engine wiring harness/connectors. Report back and we can go further if necessary.
Click to expand...
M&M, I am about to check the ignition switch for continuity. I used the FSM to pin point where the ignition switch connects up to the bulkhead and where the wires should go from there.

According to my FSM:
IGN 1 = N
IGN 2 = Q
Start = T

You mentioned how I should check P + Q which would check the "Start" position for the key. Based on my FSM and the start being T wouldn't I want to test T + P to check the "Start" position?

Also, I am guessing I should do this with the battery disconnected? (negative cable)
 
OK, testing done. Here are the results.

FYI, I couldn't get to P at the bulkhead as it bypasses it. Instead I used the BAT stud on the alternator as that is where P terminates.

I tested with negative removed from the battery.

N & P:
  • Continuity with driver door open, key not in ignition. 50 ohms
  • No continuity with drive door closed and key not in ignition.
  • Continuity with ignition switch in run. 1 ohm
  • Continuity with ignition switch in run while wiggling. Unknown Ohms (I was testing alone)
Q & P:
  • Continuity with ignition switch in start position. Unknown Ohms.
  • Continuity with ignition switch in start and wiggling. Unknown Ohms.
Interestingly, I also had the continuity signal from the DMM between N and the Hood latch. The Ohms were 50 but the DMM was giving me a signal.

This would indicate what my car is showing. It will cold start just fine and drive just fine on the first leg of the trip. Its the second leg, after it has sat for a few, that the problems shows up in.
 
In case anyone is still watching this thread.

The ballast resistor and the switch both tested correctly.

I switched over to a MDS Blaster 2 coil just in case the old Accel was the issue.

Took it for a spin over to a buddies place. Drove fine, experienced one hicup but nothing like before. Did another longer trip with no issues.

Not totally convinced it is fixed so I am going to change out the bulkhead connector and the engine harness anyway.
 
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