Hi I am new here and to owning a 2nd gen Ram. I recently purchased a 4x4 1500 V8 5.2L. I have had a check engine light on for a while. So I checked it out and replaced the part. I noticed not a lot of maintenance had happened to the life of this truck. I replaced the battery, serpentine belt, belt tensioner, Idler pulley, coolant sensor and spark plugs.

A couple I did this; my volt reader/ gauge says I'm running at 14.5/15. Normal right? The truck started dying on cold starts and Well I drove it and it start climbing to 16-17 within a hr. So I replaced the Alt; and it's still doing it. I check my grounds again also my ECU/PCM noticed that the previous owner installed a Jet Preformce thing onto the ecu. Uninstalled it and starts up fine. But volts are still slowly climbing.
Cables are not hot, alt is not hot, battery is cold. Any Ideas?

 

Need more info: What year is the truck ? Pre-98 has a conventional voltmeter, after that the needle is controlled by the PCM.

 

Did you get a volt reading with a meter on the battery to verify the dash gauge is reading correctly?

 

1995 is the year
No I haven't volt checked the gauge, it had been working fine till I fixed things and I checked the battery with the truck on and off, says 12.5-13V. I did a system check and Everything is doing its job. Except I went from 810cca to 827cca on the battery. Is there a adjustment for the tensioner? I know it self adjusting but what if my belt is too tight and no nvm.

 

So what is measured voltage at the battery when the gauge says it's overcharging?

 

12.5-13v however on start it's at 14.5 on the Guage. Truck warms up and boom 15-16.5v slowly climbing up to 17-18

 

Is that AT the battery? Or on the gauge??? If that's at the battery, likely the voltage regulator is failing. However, if your meter shows 12.5 to 13 at the battery, but the gauge shows 14.5 with the engine off, the gauge is just inaccurate, and it's no big deal.

 

Ok on a 1995 the dash gauge is independent of the PCM which is what controls the charging voltage. As already suggested, confirm the voltage at the battery when it's showing high voltage on the gauge, then use a scan tool to see what the PCM thinks the voltage is.

 

The battery reads at 12-13v, the Guage reads at 13-13.5v before start up. After start up reads at 14.5- 15v. As truck warms up to temp. The Guage creeps up to 15.5-16v; as I drive it crawls to 16-17v. I haven't check the PCM.

 

So the gauge is wrong right from the get-go.