'03 Ram 2500 QC Cummins 4x4 auto exhaust brake electrical issue..

Have nothing but good things to say about the '03 Ram 2500 QC Cummins 4x4 automatic I bought going on a year ago. Clean, solid truck, with everything working well - or at least it did until I went to our local NAPA and had two new batteries installed to replace the tired pair that came with the vehicle.

When the new batteries were in place and the extra wiring properly attached the truck started right up and ran perfectly. However the dashboard panel would't work correctly. No speedometer or tach, gauges not working, warning lights etc. Went through the wiring carefully once again, unplugged and replugged things, repositioned relays and suddenly everything on the dashboard panel began working again.

Had to go to Show Low yesterday, a 40 minuted drive each way. While we were on our way I switched ON the PACBRAKE exhaust brake, which has always worked flawlessly. Seconds after switching the exhaust brake ON the dashboard gauges and lights ceased functioning and the exhaust brake fully activated. I immediately switched it OFF and everything on the dash panel returned to normal function.

Went back through the wiring again this afternoon. Everything looks like it did prior to the new batteries being installed. However nothing I can think of doing eliminates the problem I have when the engine is running and the PACBRAKE exhaust brake is switched ON. When it's OFF the dash panel works perfectly. When the truck's running and the exhaust brake is switched ON, a few seconds go by then the dash panel gauges quit working and the exhaust brake kicks in full on. Have to shut if OFF for the panel's gauges to start working and the exhaust brake to open up again.

Anyone who's had a similar problem and found a way to remedy it - please let me know!..

Thanks guys!..

 

I would check grounds and double check the battery cable terminals are shiney and tight. get dielectric grease and a wire brush on those ground points.

Let us know what you found.

Cheers, Ron

 

Agree with Ron above. I would remove all the grounds around the top of both qtr panels and clean everything.

 

X3 on the grounds.

 

Thanks Ron and everyone. I'll get back to it this morning. Will check, clean and reattach everything. Have to pull a tandem axle flatbed trailer to west Phoenix early Saturday to help a family member move to a new place, and need to have this issue resolved by then so hopefully this will fix it.

George

PS: It's about a 3 hour drive from here on the Rim in the White Mountains to west Phoenix, and I'm going from a cool 65 degrees to in the neighborhood of a blistering 100 degrees in the Valley - by far not my favorite place to drive to! Oh well, I'll be out'a there by early afternoon and headed back home, so it's doable..

 

You guys were right, pretty much as I figured you'd be. It was a ground issue.

Went back through everything. Cleaned, re-tightened, passenger side battery hookups first, then the driver's side. Just about missed it again. After I couldn't quite imagine anything else being out of place, 'cause everything looked right, nothing seemed out of place at least to me, I felt around behind the driver's side battery and found a slender black ground wire, apparently having to do with the exhaust brake, hanging down still disconnected - something the installer at NAPA missed to begin with.

Reattached that loose ground wire that was hanging down behind the battery and the truck runs perfectly again. Panel gauges, exhaust brake, problem solved.

Thanks again guys for the suggestion. Always helps when others chime in with clearer insights than you may have at a particular moment while dealing with a troublesome issue..

George

 

TDR is a great powerful resource.

you're welcome.

Cheers, Ron

 

Just behind the battery in the corner is a ground bolt, put it on there.

 

Dont forget shiney with wire brush, then dielectric grease to prevent corrosion.

we used to install sensitive command and control comm systems, that required dedicated isolated grounds. You wouldn't believe how many electricians would tell me a ground is a ground is a ground. Not much worse than a "dirty" ground, especially with sensitive IT and C2 systems.

Cheers, Ron

 

Thanks again guys. The ground cable to the negative battery terminal connector on the driver's side is attached directly to the steel fender with a smaller ground cable.

Running the short ground wire that NAPA's installer left unattached to the negative terminal on the battery, solved my problem. That slender ground wire was just long enough for its copper clip to attach to the negative terminal clamping bolt. With the molded medium size ground cable running from the negative battery terminal connector to the steel fender in place, what I have is a direct ground connection from the negative terminal to the vehicle fender - which is how the electrical system has been configured from the day I bought it.

If anything this proves the old adage that if you want something done right, do it yourself - with a little help from your TDR friends! ..At the very least next time around I'll know what to look for wiring wise if these new batteries every need changing out again.

 

AKA ground loop