Driving home one day and the truck dies like it ran out of fuel, at the same time I smelt an electrical burn. Then turn the key to start and nothing happens.
The fuesable link that leads to the ecm was gone. I replaced it and as soon as i turn the key to start it burns again. I took it to a shop after a few days of trying to fix it. About 2 weeks after they had it they say the ecm is bad. These guys dont seem to be very smart I even had to lend them my shop manual so they would have electrical drawings,
My question is, Is this something that the ecm could cause ?

I told them i would have to take the truck some where else if they couldnt fix it thats when they decided what was wrong, I even had to help them figure a few things out on the truck.

 

I would think the ECM would smoke before the fusible link. You have a short somewhere else. Take it to somebody competent enough to isolate the short and not trying to BS you into throwing parts at the problem.

Edwin

 

ECM has the voltage reg for the alternator, and 4th gear (overdrive) control for a automatic with a A518....probably cruise-control, and some controls for the intake pre-heater, etc.

My swap is ECM-less, so no, you don't need it...but you do need some of the things it does.

 

My vr is on the firewall trans is 5 speed no crusie control

your swap ???

 

If it is an early non intercooled truck it doesn't have the ECM that controls the voltage regulator.

I would expece a bad connection on the FSS or a bad FSS.

 

I have intercooler. Truck was built in June. What is FSS

 

Fuel shutoff solenoid, as others have said, there is a large short somewhere causing the link to blow. It has to be a pretty significant short as well.

The only thing your truck really uses the ECM for is grid heaters based upon your description of the truck.

I would seriously say spend the 35 bucks for a 91 factory service manual form Genos Garage. It will save you mucho time and money working on it yourself, and let you know when a shop is trying to BS you.

https://www.genosgarage.com/product/...ervice-manuals

 

Check out this thread....might be of interest.

"De-computerize your Dodge" - Dodge Ram, Ramcharger, Cummins, Jeep, Durango, Power Wagon, Trailduster, all Mopar Truck & SUV Owners. Dodgeram

 

Back to the original problem. The circuit that's blowing the link powers the FSS, the OD solenoid, manifold heater relays, and maybe other circuits. The point is that the only protection for that d*****8 blue wire is the fusible link, and the wiring runs all over the engine, and mostly in harms way, like past linkages.

Find the short. Odds are the PCM is fine.

Pcm controls preheat, overdrive, tachometer, speed control, and alternator (91.5-93) It can be bypassed, but it's a bunch of work. They actually are quite reliable, unlike the cheesy wiring harness and connectors supporting it.

 

No Tach or Alternator control on 91.5, that came in 92 and 93.

91.5 is a half year marvel.