Gauges went crazy!

[TH Cummins]

I went and got new batteries, my old ones were junk. All was good for a while but now my lift pump isn't running, at all. You can bump the key and I don't get a cycle, and if you try and start it, it will just crank. I'm not sure if it would just be the relay, the ECM, or the lift pump itself? Any of those things a common problem? Thanks

[Ironforger]

See if you have voltage at the lift pump when you bump the key.

[Mopar1973Man]

Ok so now my main concern is the issue with it not starting. I atleast want to be able to start it and move it around before I bring it somewhere to have the ECM flashed. The batteries will barely crank the truck over, sometimes it starts and others it will crank for a short period until they are dead. If I check them they read 12.8 or higher every time but still barely crank the truck.. Does this mean the batteries are junk? Just seems weird that they read good on a tester

When batteries fail they don't have to fail with low volts but then can fail where they no longer have CCA ability to twist the engine over. As battery age they will continue to charge but the plate will degrade and amperage power will degrade. It's possible. I would have the batteries load tested.

[Ironforger]

If it was me, I'd be thinking about ruling out the instrument cluster. Have you tried swapping out the instrument cluster? I know that most people might not have a spare instrument cluster laying around, but if you can find a known good used one, try swapping it out. If issue continues then the instrument cluster is ruled out and start looking elsewhere.I know I asked this before, but have you checked all of the ground to body terminals? There are quite a few under the hood alone. Did you check the ground terminals on the drivers side below the headlamp? (kind of in front of the battery) My truck has 2 in that viciniity. one looks like it's grounding a whole cluster of circuits, more than likely electronics. Grounding issues can cause all kinds of problems. A faulty ground could easily cause the issue you describe.

[kicker212]

good luck

[TH Cummins]

No I haven't tried a different cluster. I guess that would be an option if I could get my hands on one. Does anyone know if the ECM also controls the tach? Because now my tach started coming and going as well?

[TH Cummins]

So I went to the dealership this last week and had the ECM reflashed. The check engine light was on and they gave me a code for a Crank Position Sensor. I replaced the sensor and starting issue is fixed. However, my check gages, check engine, water in fuel lights are all on, and the oil pressure gauge reads 0. I thought for sure this was due to the ECM needing a reflash. Any ideas? thanks

[Wild and Free]

:banghead: The tech should have seen this issue while he was hooked up yet and narrowed down the issue right then, WTH was he thinking?

[TH Cummins]

Actually the lights just go on and off as they please. None of the lights were on when I brought it there of course

[Gridcon736]

:stuned:This seems very familiar to me, just throwing this out there,but have you done an APPS reset at any time? I am still having gauge issues but I can now get them to come on and read correctly. My problem is that they will just go off at random!:banghead: I'm leaning towards a new APPS for mine, anyhow.... try the APPS reset and see if it helps,I believe you are supposed to do this any time you have the batteries disconnected for any length of time? I feel your pain, my 99 has been giving me a real education on Dodge wiring,just keep on - keeping on and you will find it!