my check engine light has started to concern me. the past two nights in a row it will come on at start up, then if i turn off the vehicle and turn it back on the light goes off. whats up?

 

read for codes would be the first step

 

did that...i got a 41

 

alternator issueshttp://jeep-xj.info/HowtoECUcodes.htm

 

I agree with freegdr, in my experience a 41 is usually related to the alternator itself.

 

i got a 41

the CEL comes on at start up,batt gauge reads a discharge until the temp comes up a tiny bit?, then it will hit full charge, if i turn it off and then back on at that point the CEL goes off.

i should also mention that the belt has been off just recently and this has started after reinstalling it. it also does squeal. it was much worse and have tightened it down twice now to where it seems tight but still squeaks a little, no where near as bad as it did.
I have been told to just keep adjusting it until i find the sweet spot. my question in that regard is how tight ?, and do i need to loosen the power steering pump to spin the adjuster or can i simply turn that bolt and tighten the belt with out loosening anything else?

 

The belt on the 4.0 needs to be pretty darn tight to both work properly and to stay quiet.

I wouldn't replace that alternator quite yet, until you have all belt issues resolved.

If the belt is older and you are still having trouble after snugging it up, replace the belt.

I like the Goodyear Gatorback belt for a replacement. Less stretch; quality belt.

 

do i need to loosen the power steering pump to spin the adjuster (below the power steering pump) or can i simply turn that bolt and tighten the belt with out loosening anything else?

 

OK, I got a Alternator out of my stepdads parts Jeep and this morning I go out to take her to the parts house to test my Battery, the existing installed alternator as well as the replacement, expecting to get in and see the CEL on and the volts down at about 10..but NOooo!.//facepalm...she decided to fire right up,show a full 14 volt reading, and read FINE at testing..cmon...really?..sooo now what...

soooo frustrated.

 

Replaced the alternator. fixed.