No Bus 99 dodge 24v

[Rocko]

99 Dodge 2500 24v p pump man trans.  WT- ground wire mod has been done. Fass pump.  It started periodically no gauges then a mile or two down the road all gauges would start working ? Was always in a hurry. Never messed with it. Have a Edge II and it would lose connection, touch the screen would it come back on screen. Never showed NO BUS on dash, when this took place. This has probably been going on close to two years. I never was able to look at it. I got Covid 4 times and was very sick. Better now. Gauge issue has gotten much worse as of last month. I would cycle the ignition and the gauges would stumble and eventually come back. If the truck sat for 2-3 days batteries wouldn't spin it fast enough to start. Jump pack and it was running. Put a maintainer on it and was fine, not fixed. Would lose power to camera recorder, hard wired. Noticed no brake lights. Bought a brake switch and took apart and it was a mess. Separated the melted wires & shrink tubing. No brake lights with new switch and shrink tube. Ran a wire from loom for brake lights. Their working. No gauges, no charging, couldn't drive the truck. Would no say NO BUS and nothing at the OBDII plug and grid heater relays disconnected at battery. So here I am. New batteries, alternator check by two different companies, alt is fine. New battery terminals, everything cleaned as far as cables lugs. New solenoids for grid heater.  All ground cables frame, fenders all tight and clean. Checked 3 plugs on PCM, all were clean, spotless. Pulled plug on ECM, clean, spotless. I have not checked for continuity. Had another ECM from a 99, tried it. Started engine and alt gauge is working and charging, no other gauges working. Check with DVM and charging 12.2 up to 17.4. Shut it off. straddling engine and forearms touching intake horn and little tingling and realize I was getting shocked and the longer you continued to touch the more it would grab you. Pulled PCM Plugs, nothing. Pulled plug ECM and it was very minimal shock. Pulled 1 lug at time off the positive terminal. Fass pump pulling a lot of amps and trailer brake controller. Disconnected both draw on battery was cured, I guess. Check with DVM and do not remember numbers with positive cable removed and DVM. Thought Fass motor was bad, it is fine.  Truck still starts and now wait to start light is coming on and hasn't came on in several years. ? Pulled dash to remove check engine bulb and now no cluster lights on dash WTF. Put original ECM back. Hook everything as it should RS completed. Go to LS and do the same. Turn key and start it all quages & tack working Check engine light on since P pump install, no other error lights. No wait to start ? I decided to leave bulb in for check engine until this is all corrected.  Shut off and started 5 times and everything worked as it should as far as dash.  Checking everything and anything plastic ties. Start the engine Now, no Check engine light 2 minutes later comes on ? 12.2 DVM at battery. Just let it run, 5 minutes later check it and it's at 13.6 charging DVM. No guages. no OBD no cluster. Shut it off, start no guages, cycled key 12-15 times guages moving start it again quages working and not charging by guage or DVM. Shut it off, done for the day. I unplugged Edge completely, had no effect. I unplugged PCM and started fine had no effect being disconnected. Oh and a VERY minimal shock. Nothing like it was. Fass disconnected and brake controller disconnected and started and ran long enough and no change. Check engine comes on in a few minutes. I might of missed a description or a something else it did. But that's a good start. Guess I'll be send PCM & ECM to Florida to be checked. I'm open to any suggestions. Have to excuse my form of explaining.   Thanks

 

[Great work!]

You put a p pump on it right? Assuming a manual tranny. 

 

You can put an external voltage regulator on it lots of info and videos on the web. That will give you stable battery voltage. That would be a good start. Check connectors there are some behind the fender skirt that go to the back of the truck on drivers side. 

 

Just open ALL connectors and spray clean then re-seat .

[Mopar1973Man]

If the PCM is damaged there is no way to get the CCD Bus problem to go away. I would at least do some checking and see if you are getting 2.49 and 2.51 volts on the CCD + and CCD - pins versus ground. This is the normal rest voltage of the CCD Bus after all the modules stop talking. Then the instrument cluster is the device that sets this bias voltage of the bus.