So my older xj (1990) is dragging down the alternater when i have my headlights and heater on. I went and replaced the alternater with a new 105 or 106 amp alternater. its charging a little better but is still on the lower end. Should I look at replacing the belt as well or what? I cannot find a tensioner pully and dont really know what else to do, with snow on the ground makes for great night time playin' but not if you can run your headlights and heater let alone the winch if needed.

 

You have no tensioner pullet you have to adjust the belt from the Power steering pump. Underneath it there is a a slider system.

You can check to see if you belt is loose by twisting it. If you can twist it past a 90 degree angle easily then it is too loose, if you can't even make it to 90 degrees then it is too tight.

 

alright stryker, got the new belt on and tight, not too tight. so thanks for the input in regards to that.

now it does do a alittle better but still not what I think that it should have any other suggestions on why it is not showing a charge better than that? It stll drags down not quite to the red zone on the battery gauge like it use to but it gets close. Battery is brand new, alternator, and now the belt, the battery gauge rides just under the 14 (half way) without the heater and lights on, as soon as these are on it starts fallin

 

I recommend checking out your main battery cables. Start at the battery and chase the positive all the way to the starter and alternator looking for crack, burns melted insulation or bare wire shorting against metal. Do the same with the negative and follow it all the way to the grounding stud on the right rear of the engine block. That stud is known to be forgotten about and it gets nasty with oil, dirt, corrosion and crud. Ensure the negative cable is in good shape and the connection to ground is tight.
Have you noticed if any of your power accesories are completely inop.?? Something not working could lead you to the scene of the crime (I.E. shorted of broken wiring.

 

i appreciate your responses to this i will check the cables as well as the ground tonight and report back, as far as i know all of my power accessories operate as they are supposed to, windows, of course the lock actuators are junk but one or two do work still, radio, lights

i'll check the cable before i go any further
thanks again

 

how are you checking the charg rate

 

well i have been like an idiot watching the dummy gauge on the dash, but with my headlights on and heater on its dam near in the red, i went and got new battery cables which mine were in horrible shape hoping that it would solve the problem and nope sure did not, did these alternators have built in regulators or not?

 

yes they have a duilt in regulator

 

look in you power distribution box for your
alternator output fuse

its 60 amp blue
listed as #1
should be the large fuse closes to the front

 

i have replaced the battery cable and did a little cleaning around the connections while i was at it, i'll look in to the fuse, what does it do? does it tell the alternator to kick it up when more items are ran?

thanks for all your help everybody

 

mike i am not finding the fuse that you are talking about did all 1990 cherokees have that? I put the battery on charge overnight but still with nothing running its still showing a significant strain, when i use the winch its all the way to the red. I have done some reading that sometimes the headlight switch can cause other issues i may check into this and give it a try at least

 

I have a 91 so not sure if you will have it in the same spot
90to92 should be the same

it should be in the power distribution box under the hood in the lid it will tell you what fuse operates what system

 

there is no power distribution box under the hood there are plenty of replays. I am going to replace the headlight switch I already had one and my lights stayed on the other day after i pushed the switch in. I have been told that there are so many ciscuits that run through it that it by chance may be casuing my problem. I'll keep ya'll posted