I am new to this forum but hope that people can help me with my problem. I drive a 2004 Dodge 2500 Cummins 5.9 L diesel (automatic). When I drive my truck my gage light comes on. The volts on my battery go down to 8. I changed out batteries on Saturday thinking maybe that is the problem. Both batteries were cracked and leaking so thought it would be best to replace both to them. I drove my truck and it still did the same thing with the gage light. Went back to AutoZone and they checked everything and regulator failed. We replaced the alternator and then drove truck again and the light came back on. Took truck back to Autozone and they said it is prolly the ECM. I contacted my local Dodge Dealership and they quoted me $2,000 for the part itself!!! I have done some online searching and have found refurbished ECMs that I can get $500 to $800. I found a place called Auto Module Source? Are they trustworthy? They say they program the part for you and send you part and you should be able to plug it in and it should work. What are y'alls thoughts and has anyone ever replaced their own ECM with a ECM part from online? I just don' thave $2,000 laying around My truck starts up fine and does drive fine. I just really don't want to be stuck on the side of the road! My bf had checked wires, cables, etc and he said they looked fine. Any advice appreciated! Thanks!

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Is there any trusted good place to a good used ECM or re-built one? I have been doing some online searching and feel like any site I see maybe a possible scam. If anyone could help it would be greatly appreciated!

 

Are the rest of gauges working ok? if any of them arent it will trigger the light,The charging issue is resolved 14.5 volts or so? I think (not 100%) the computer that "watches " the gauge light is in the gauge cluster itself,maybe for the hell of it plug in & check for codes

 

Thanks for your reply! All of the other gages seem fine. Just the only gage that goes down is the battery gage. When I started my truck this morning the battery volts were a little under 14. A little less than a half mile down road the volts creeped lower and lower until finally it just went to 8 and the check gage light came on.

 

Ok, when this happens,I would go out to the out put post of the alternator check the voltage there I see you replaced the alternator,but sometimes you may get a bad one, sounds like you are not charging so the gauge light is doing its job,problem is elsewhere,another test: with the truck off probe the out put post of alternator to make sure it is connected to the battery it should be. Check belt tension to make sure it is not slipping. Pretty sure that voltage has to be put in the alt. to get voltage out via the plug on the side but I have never played around with the later Dodge to tell you where to go on that, Hope this can help