4x4jeepmanthing

Hi all,

yesterday driving down from the mountains my 99xj threw a check gauges light off and on the whole way home. I waited until I got home just incase the vehicle wouldnt restart. upon doing so I checked voltage at the battery 13.98, BUT I havent been able to check this when the check gauges light is on, every friggin time I hopped out of the jeep and threw the VM on it the light shut off. All my dash lights are LED and they were pulsing lightliy.

When my alternator went out the first time my gauges dropped, not pegged. This was a few years ago and I now rock the 136A alternator with 2 awg wire and a breaker. duracell agm battery, 3yrs old.

Today Ill be checking/ cleaning wires
I tried getting a code from a really cheap scanner that gave nothing

So Ive been reading a lot on this and a few of the usual folks on here say that pegged gauges usually indicate a wiring issue, these cables a very new- I WILL check anyway and clean.

a lot of folks chime in with a bad PCM being possible because my year has the voltage regulator built into the PCM.

Ide like to know if the battery temp sensor( newer) could play any issue in this, IF I dont get a high voltage reading with the check gauges light on and the VM replicating this 19V?


otherwise all I can think of is clean/check/ re attach wires for now.



what say you?



thank you

treemonkee

I would check my grounds, bad grounds give really weird symptoms. Was 14 v with the engine running?

BlueRidgeMark

The newbie is right on the money.

Check your grounds first. See my sig, #1, for a link to photos of all your ground points.

Don't pull the trigger on a new PCM until all other possibilities have been exhausted. Yes, it's possible, but it's usually not the PCM.

4x4jeepmanthing

Ok some new info,
Yes the 14V was with the engine running.
I just got back from a drive while the MV was hooked up.
So it would be 14V while driving then it would drop to 13.10V and check gauges would come on and the dash gauge would peg 19V. Usually this light will go away after stopping.
The alternator sounds like a light pebbles rumble.

im currently going to get the battery load tested at oriellys to make sure its not damaged, then ill dig into wires.

IJM

Been there, done that. It's probably your battery cables or ground. There's very likely no actual voltage spike despite what your gauge is telling you.

robsjeep

Yeah, it is unlikely you actually had 19 volts across the battery, likely a gage error. the battery tends to short when high voltage is applied, reducing the voltage spike. so your 19 volts is likely not real.

4x4jeepmanthing

I cleaned all wires and reset the breaker a couple of times to make sure it worked. We did a 3hr+ drive and so far I did not get the check gauges light again.

thank you all for entertaining this topic again.