help with my 320a alt

[nej89]

so i installed my 320a alt today and i got it set with the adjustable voltage regulator by tunring the screw clockwise to stay at 14.5. i used my dmm that i bought from the matco guy that comes to my shop once a week. at the dmm its stays at 14.5 volts but on my dash it will read 14.5 and then after like 1 minute my voltage shoots up past 19, but that is all on the dash. my dmm never changes what is reads. so i decided to take my cherokee for a drive to see if that helps.....well it did a little. it will stay at the 14.5 on the dash and then shoot up just like at idle but then after driving for a little longer it goes back down to 14.5. does anyone know what is goin on here? could it be a bad voltage reader on my dash. it is still the stock one from the jeep. or could it be a bad altinator? thanks for the help.

[MECHMAN]

You have a problem common to Jeeps. As a safety to prevent overcharging the Jeep's voltmeter will peg all the way over to the 19+ side of things any time it see's voltage over approx. 15.3v. It will sometimes illuminate the "check gauges" light as well.

Verify proper charging voltage with your multimeter to insure it is not overcharging, but this is a common problem that we have seen in TJ's and Cherokee's gauges. Basically it's a fancy idiot light.

I got your message, just didn't want to call too early and wake you up. We were gone Fri-Sun, PRI in Orlando, but are back in the shop and here if you need us.

-Eric