Archived Electrical diag help needed ASAP please, DOA truck.

[Jeep Hauler]

This is a big deal for me since I use the truck for work, & I need it to run, and I am on call this weekend...



2005 Dodge Ram 3500 4x4.



OK, in order, events that took place:



A few days ago the truck stumbled momentarily, set a code of 2146, belched a little smoke and then ran fine. No problem after that.



Today, I started my truck (warm) and was idling when my "check gauges" light came on. The volt gauge was sitting on 8. This did not make sense to me since the truck was running fine. I figured if it was really 8 volts, then the fuel pump etc would not be working right. So I check with my multi-meter and the charging system is putting out 11. 5 volts. Ok no problem, haul butt home (40 miles), to start pulling the alternator and have the wife PU a new alternator. All this time the gauge is still at 8. Pop hood and start to dissasemble. At this time I noticed a pretty good arc from the NEG batt cable when I pull it off. Hmmm, Ok I will check the charging system again before pulling it all apart. Start truck & check voltage. It is now jumping all around from 11. 5 to 13. 2 and back. So I pull NEG cable off again to see if the alternator is holding and maybe I have a bad batt. Truck runs for 5 seconds then stumbles and dies. Ok alternator bad. Check codes and find 2509 and 2502 now.



Switch out alternator and wrestle that stupid dang 10 foot long serp belt, get it all back together and start truck. All is well @ 14 volts, grids are cycling a bit, truck warms up and then the volt gauge went back to 8!! WTH?? Check with multi-meter again and voltage is jumping all over the place again, but now going from 11. 5 to 14. 6 very rapidly. Turn on headlights, all seems normal there, no flickering etc. Decide to try disconecting NEG batt cable again while running to isolate the alternator, and truck dies like before, so I think dang bad alt out of the box. Reconnect batteries, and now the truck will not start, I cannot pull codes, and the volt, fuel, oil, & temp gauges are not working. The RPM and MPH gauge jump a little when I cycle the key like normal, and all the warning lights test work, the odometer lights up as well as the gear indicator lights. What the heck is happening here? AlSO the low beams do not work (high beams do) and the lamp out indicator is chiming due to the low beams. I checked all the fuses and all look OK. Please help, if this truck dies, I am SCREWED!



Thanks in advance,



Danny

 

[rkressg]

Sorry, Not of much help, but on the older (my gen truck) the voltage is regulated by the PCM. Maybe the computer is fried??? Almost sounds like it with all the gauges not working. Can you try disconnecting the wires to the PCM, cleaning, packing with di-electric grease, and reconnecting. Loosen, clean, and tighten all the grounds you can find (including the PCM).

Hopefully someone from the 3rd gen forum can say something here.

 

[Hoefler]

You have direct short some where. The jumping voltage is from a breaker popping and resetting. You should not disconnect the batteries while it is running, you can fry the alternator and a bunch of other things. Take the negative cable loose, hook a test light to the cable and the other end to the battery. The light will glow, start pulling fuses and breakers until the light goes out or becomes very dim. When the light changes the most or goes out, you have found the circuit with the short. If you have a multimeter, you can use it instead of the test light. Set the meter to DC amps, hook the red lead to the negative cable ant the black lead to the battery. It will show you how many amps is being drawn, pull the breakers or fuses that are close to the amp draw that the meter is showing until you find the draw go down.

 

[p-Bar]

sounds like the solenoid for the grid is stuck try disconnecting that, it's at the passenger side battery

 

[Jeep Hauler]

OK, there is a large 20A draw coming off somwhere. I checked the fuses and grids, but can seem to find it. I just hauled it to the dealer and they are going to do a diagnostic. Supposed to be under $100 for this, so I will post up what they find.



Thank you for your replies.



Danny

 

[Skydiver]

I agree,,,follow Hoefler and P-Bars advice. Does sound like a breaker cycling.

Some where a wire has became raw.

 

[Jeep Hauler]

Fried ecm?

Dealer says the scanner will not communicate with the truck. They "think" the ECM is fried but no gurantees. New ECM is $2300 including the flash. Any other ideas to double check? Everything the the truck workes electrically except a no start (cranks over OK), no fuel pump & no grid heaters. It will start with ether though.



ANY NEW IDEAS NOW?? Best place to buy a cheaper ECM???



Thanks!!!!



Danny



EDIT: ADDITIONAL INFO



I tested the "C"-code function and the instrument goes through it's test and all gauges move etc. There are no C codes. Just AA 00 then 00 00. The hours come up as 4007 hrs. So if this helps narrow it down.

 

[Jeep Hauler]

Repaired.

After dealing with a very poor customer service at a place that specializes in re-manned ECM's, I finaly broke down and purchased one from a different Dodge dealer (saved $800 at least). When replacing the ECM and re-flashing it, we had to un-plug the ABS module then plug it back in. This was due to a VIN mismatch according to the DRB tool. While we were in there I had them do a tire size recalibration as well as activate my DRL's. I did forget however to have them enable the 4th gear lockout. Anway, thanks for all the replies, and I can go back to work now!Oo.

 

[tp0d]

Did you take apart the old ECM and see if there are any burnt areas? Kinda wierd to lose the computer like that, if there are no rubbed wires/etc... I would definitely go over every wire I could find -very- closely. Its possible you could short out a wire fed by the ECM, and blow the ecm. . hell, could blow the new puter right up.

I have an 05 also, so I`m curious. .

good luck

-j

 

[Jeep Hauler]

I was going to when I noticed how sealed it was with silicone. So I did not want to void my core charge.



After processing everything I think it came down to a couple things:



One of the ECM connectors seemed loose when I was taking it out, which I work in the oil field, and the roads are horrendous. This maybe causing severe vibration, which may have contributed to started my problems in the first place with the volt gauge not reading. Then when the battery had a load on it and I disconnected it, the arc must have caused some type of surge.



Also my new ECM has a Cummins sticker on it and the old one did not. Not even a Chrysler sticker. Now that I have been driving it a couple days, my power has increased, I have noticed a pretty good increase in mileage (maybe from the flash which included all the lateset programs), and ever since I had bought it, I would have a hesitation on a full throttle take off (like pulling out on an acceleration lane), and that is gone as well. The turbo kicks right in.

 

[Huff N Puff]

You never,never,never

This is a big deal for me since I use the truck for work, & I need it to run, and I am on call this weekend...



2005 Dodge Ram 3500 4x4.



OK, in order, events that took place:



A few days ago the truck stumbled momentarily, set a code of 2146, belched a little smoke and then ran fine. No problem after that.



Today, I started my truck (warm) and was idling when my "check gauges" light came on. The volt gauge was sitting on 8. This did not make sense to me since the truck was running fine. I figured if it was really 8 volts, then the fuel pump etc would not be working right. So I check with my multi-meter and the charging system is putting out 11. 5 volts. Ok no problem, haul butt home (40 miles), to start pulling the alternator and have the wife PU a new alternator. All this time the gauge is still at 8. Pop hood and start to dissasemble. At this time I noticed a pretty good arc from the NEG batt cable when I pull it off. Hmmm, Ok I will check the charging system again before pulling it all apart. Start truck & check voltage. It is now jumping all around from 11. 5 to 13. 2 and back. So I pull NEG cable off again to see if the alternator is holding and maybe I have a bad batt. Truck runs for 5 seconds then stumbles and dies. Ok alternator bad. Check codes and find 2509 and 2502 now.



Switch out alternator and wrestle that stupid dang 10 foot long serp belt, get it all back together and start truck. All is well @ 14 volts, grids are cycling a bit, truck warms up and then the volt gauge went back to 8!! WTH?? Check with multi-meter again and voltage is jumping all over the place again, but now going from 11. 5 to 14. 6 very rapidly. Turn on headlights, all seems normal there, no flickering etc. Decide to try disconecting NEG batt cable again while running to isolate the alternator, and truck dies like before, so I think dang bad alt out of the box. Reconnect batteries, and now the truck will not start, I cannot pull codes, and the volt, fuel, oil, & temp gauges are not working. The RPM and MPH gauge jump a little when I cycle the key like normal, and all the warning lights test work, the odometer lights up as well as the gear indicator lights. What the heck is happening here? AlSO the low beams do not work (high beams do) and the lamp out indicator is chiming due to the low beams. I checked all the fuses and all look OK. Please help, if this truck dies, I am SCREWED!



Thanks in advance,



Danny

NEVER disconnect a battery cable while the truck is running. You could smoke every module on the truck. You could also smoke a whole arry of expensive sensors. It is not a good way of checking the charging system. It was the way, old timers checked charging systems,it was a bad idea in the old days,and its a even worse idea now days with todays sensitive electronics.