So is the electronic ignition box supposed to shock you?

[Stumpy]

So I was driving to the local Friday car meet at the burger place and i was sitting at a light a couple minutes. Car was fully warmed up, ran great for 10 miles or so then just quit. It didn’t stall. It didn’t sputter. It just was running great then not running. I crank it once. Nothing. Crank again and pump a little gas. Nothing. Give it a little more gas turn the key and it starts right up and runs great.

So I go to the car meet and talk to another Mopar guy and we both agree that it sounds like the electronic ignition box. Now I just took the whole dash out and changed the instruments into a new bezel and reinstalled and removed an FM converter box. So I might have screwed up somewhere. I was really careful making sure the instrument cluster was screwed down so it grounded and got it hooked up right, paying special attention to the ampmeter wiring but I could have screwed up I guess. I also just deleted the radio so that OEM plug is unplugged. There’s no bare wire to ground out though.

Anyway, I drive 20 minutes home and the car runs great. Get into the driveway and opened the hood while the car is running and wanted to check connections and obvious grounds. Then I put my hand on top of the (made in Mexico) orange ignition box to see if it’s hot and get a little jolt. So being the idiot I am I put my hand on top of it again to make sure. OUCH! YUP it is definitely giving me a little electric shock.

So does the ignition module give a shock if you put your hand on it while running or does it indicate it’s failing? Is there any way to test if it‘s pooping out? The shock seems to happen when I put my hand on the blue plate.

What’s up with that?

 

[Dana67Dart]

Did you touch the transistor? Which looks to be a real transistor.

I would not expect to get a high voltage shock off the box but I recall something about the transistor being able to shock you or something like that.

Maybe the box is not well grounded???

 

[Plymouth 65]

The ignition box should be properly grounded. It should not shock you while running or not. 65'

 

[Stumpy]

Did you touch the transistor? Which looks to be a real transistor.

I would not expect to get a high voltage shock off the box but I recall something about the transistor being able to shock you or something like that.

Maybe the box is not well grounded???

If that little round silver doodad is the transistor, yeah I probably touched it. It wasn’t a big shock. Doesn’t the box ground through the housing? The box should be well grounded, it’s securely screwed tight to the passenger side fender well. I could take it off, clean the screws and scrape some paint off where it attaches to make sure.

 

[RustyRatRod]

As @Plymouth 65 said, the ignition box MUST be grounded good. That means scrape the paint off both the box and what it's mounted to. I always run an extra ground wire just to be sure. It sounds like you were a ground.

 

[Dana67Dart]

IMHO a lock washer between the body of the ECU and the firewall at each attachment point will work well.

Green= Transistor
Magenta = heat sink
Yellow = insulation

You can measure voltage between the transistor and the body of the ECU, not sure how much.

Look at 17:22 (ZAAAAP!)

 

[67Dart273]

HA,.........HAHAHAHAHAHAHAHAHAHAHAHAHAHA...HAH...ha HAH!!!!

LOL. Trying to remember the first time I got bit on one of those. Back in the '70's that is for sure.

That transistor, ONLY ON A REAL ECU (not the fake China ones) ----that transistor is above ground and connected into the coil NEG circuit, which generates a fair sized pulse up over a hundred and perhaps sometimes over 200 volts peak.

ALSO, I once had a beat up 62 FJ-40 Landcruiser, which carried a 360, a 340, and finally, a 318 in the years I owned it, and the hood leaked!!!! On some outings, getting rain, water, snow thrown around in the engine bay, and perhaps mud, etc, the ECU would sometimes short out and miss or quit running!!!! LOL -- Because of mud/ water/ etc all over that transistor.

I actually finally mounted the ECU under the dash

 

[Stumpy]

Yeah. Well the slide show answers that question. It’s supposed to bite you.

I’ll clean up the grounds and add lock washers anyway.

 

[Demonracer]

Either the inside or outside dragon tooth washers will solve most all painted sheet metal to painted sheet metal grounding. I keep both on the trailer for the race car, just in case.

 

[Bewy]

Getting a shock in this situation nothing to do with the grd connection. Post #7 nailed it. The case of the transistor is the transistor's collector, has the coil -ve back emf on it, 200-300v.
Sometimes hard to see, but there will be an insulator between the transistor case & the box.

 

[RustyRatRod]

Sometimes the toothed lockwashers aren't enough if the paint is pretty thick. You MUST scrape the paint off if you want a good ground. I scrape the paint off and add an additional ground wire.

 

[cudamark]

I can still remember the first time I got nailed with the "new" GM HEI ignition. I still can't get my curls back in my hair!