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ECU

2K views 13 replies 7 participants last post by  ETexasRamcharger 
#1 ·
Hi. I have a 1985 Dodge D150 with 318 engine. I have no spark coming from ignition coil. I have changed the coil and high tension coil wire and checked the ballast resistor. I have 12V at the + side of coil. I checked the pickup coil and ECU. I don't know what to do next. Can anyone help please?
 
#4 ·
bonicorddad said:
I did not change the pickup. It showed about 300 ohms which according to book is good. My manual says I have a short between ECU and the pickup. I am just not sure how to find it.
I misread what you wrote. You can just trace the wires back. It's a little annoying, but there are a few spots along the firewall where wiring often suffers damage.
 
#6 ·
If by Ecu you mean icm (ignition control module) then yes. Sounds like it got pretty hot.
It has some type of putty/epoxy on the backside.
While your at the store grab a ballast resistor as well. Should be located nearby on the firewall.
 
#7 ·
Should also add when you replace the ignition module, sand off the areas where it contacts the firewall. Grab some of those star washers to help bite, it grounds through the firewall and when new, the bolts were enough. Not so much anymore.
I’ve even went as far as to put a short black wire to one of the bolts, run a self tapper through the firewall right next to it, and paint over it as extra assurance it will always have a good ground.
 
#8 ·
I have had some leak for years, and still work fine. If you replace it, keep the old one as a spare.

These two gooed together just sitting on my shop shelf, and still test good. The leaking does not come from the unit itself heating up, but rather the goo itself getting soft. Loosing goo is not going to make it die quicker either.
 

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#9 ·
However, the “goo” is there to seal out moisture and when, not if, it loses enough “goo” and moisture attacks the electronics of the unit it will fail.  Not worth the risk of breaking down in the middle of nowhere.  Replace it.
 
#11 ·
Rabbit929 said:
I just replaced it because it was 37 years old.
Yeah, I did that on my frankenram. A year later I pulled out the dead chinese crap replacement and put the old one back in. If it's got a Chrysler logo, leave it alone, it's not dead.
 
#13 ·
bonicorddad said:
I did not change the pickup. It showed about 300 ohms which according to book is good. My manual says I have a short between ECU and the pickup. I am just not sure how to find it.
Is this still the same, or has things changed from this old post?
 
#14 ·
I am having this same problem on another post.

Is there a common weak link in the wiring on these early 80s trucks?
 
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