Are there any parts stores that can test ECU or electronic modules in distributors?

I have tried the big chain places and no dice. I was told that you have to have use the factory Chrysler diagnostic tester. There may be an independent electric shop around that may have an old piece of equipment to test them.

Distributors can be spun by hand quickly. With an AC voltmeter connected voltage (millivolt scale) will increase with speed of rotation. Resistance should measure approximately 270 ohms across the terminals.
Doug

Service manual has a procedure to help isolate issues, by checking for continuity through system. Makes sure ignition system good, wires good, coil in distributor ohms ok, ballast resistor ok, good ground on Electronic box. But in the end the driving test once it starts. Seen boxes start cars, but not spark right at RPM. G

Somewhere I had/have a booklet put out by Wells that went thru how to test various stuff like that.

I don't recall what all was covered, other than the pickup in a Mopar distributor, been 20+ years since I used it.

FOUND IT

Thank you, thank you!

you jogged my memory that i have that book as well. now i gotta find mine.

Ma Mopar gots you covered?

http://www.mymopar.com/downloads/mtsc/312.pdf

Now you can have it in PDF form too.

When I started wrenching in 1982 I bought a Blue Point MT133A off the Snap On truck. It's small and easy to use to pinpoint electronic ignition failures.

https://www.ebay.com/itm/Blue-Point-Tool...275.c4#viTabs_0

Did a net search. Found this

http://dave78chieftain.com/Ignition_Syste.html

I checked for 12 volts to the number one pin receptacle. Nothing. Same for number 2 pin, same result. I checked for voltage at the ballast resistor and I’m good there. Looks like it’s the harness. Just for shits and grins I went ahead and ordered one last night just in case.

The harness is simple. 2 wires from the ignition box to the distributor. One wire to the negative side of the coil. Check all 3 with an ohm meter. Ignition power to the box an positive side of the coil. The 5th wire at the ignition box does nothing.
Doug

What DVW said, confirm everything is getting fed in ign1 (run)/ign2 (crank), the coil pri/sec & ballast have continuity, pickup generating AC voltage & gap is acceptable/box & engine is grounded. all that is left is the box itself (& items can check OK when cold then act up when warmed up). EDIT & a terminal/connection can be loose/poor continuity.

Is this on the 300?

i do now ! thanks to you .....
i bet i still find mine in the last place i look.

Yes