So I have a new battery, but that alt keeps cutting in and out. I can pop the hood a jiggle some wires and it's good until I start it next time. I drove all the way to work today with it (the gauge) on zero! I even pulled over a couple of times to try to fix the wires and also restart it..... nothing.
I made it to my mechanics, shut it down and started it back up only to have it be fine! WTF!
it's a 98 xj 4l, it has the orig alt. could it be wiring? sensor? alt? if it's 12 yrs old, is that about it for an alt?

sorry so long winded, just try to feed you guys info.

Thanks.

 

Hi. Did you test the Alt on a meter? maybe its just the gauge wiring. Throw a Multi-meter on it to see if its not charging...Tj

 

This vid is of my 98 4.0 everything works properly and i show multimeter readings of what each cable does.. Good luck
Video:
https://www.cherokeeforum.com/f2/new...ge-pics-62755/


These to should help you out.. Alot of testing

If you need anything else let us know

 

Thanks guys, unfortunately I don't have the time or tools to do it myself or I would for sure!
so I have to leave it in the hands or my mechanic. I just want to be able to ask him to check for certain things. right now it shows a charge. It's one of those messed up things, it could just be wiring but like I said it's the orig alt... maybe it's going bad? the thing is 12 yrs old.

 

IMO I dont think its "Going bad" , either its good or bad but thats just my opinion...It does sound like a loose wire...Tj

 

Also a quick and easy test for alt charge will be disconnecting the pos + cable of battery.. If the vehicle continues to run, then your alt is working properly.. and that you mean you Green/Orange wire would have a problem.. Green/Orange is the one that sends the charge reading to the gauge..

Also check all grounds.. Body ground is next to the battery.. Ground for alternator is under the coil. Also check the pos + cable from alt to fuse block.. Mine broke. Just a couple things you could do that the mechanic will charge you for.

 

I dont think that the rig would still run if you disconnected the hot red terminal battery wire... have you tried that? I had alt issues about 3 years ago. The alternator can seize up if its shorting out, any squaling? alternator is easy fix. its like 3 wire connections 3 bolts and re tightening belt. you can get a new stock 90 amp for about 70$. a mechanic is going to charge you $1ARM.00. see if you can find an xj'r on here by you and buy them beer and pizza 2 help!

 

ya, there is a little squealing that I could here this morning. it's at my mechanics right now, I know him so he won't r@pe me with pricing. A new alt is about $240 Canadian, compared to a rebuild that is $40 cheaper.

 

it should still work.. I have done it.. but only as a test and for a few seconds nothing more.. On the 98 models the Alt + goes into the fuse block so if you disco the battery and the alt is still working there will be a constant charge..

The only reason why vehicles have a battery is to supply enough power to start and while using ACC.. other than that the alt is what supplies power..

 

ok, ya I wouldnt try that too long ya know? I imagine its really hard on the alternator diode, Just like jumping a dead battery is really hard on the diode and can burn them out.
I think that my alternator supplies power---> battery and from battery------> my brain box. so if I disconnected my battery I would remove a crucial link

 

whoh whoh whoh, before you hand it to a mechanic or replace the alternator, try the easy things first. Since it's intermittent i'm betting it's one of these things:

1. Clean up the ground at the battery, and at the engine block (behind the valve cover). Also replace the wire/strap if broken or corroded inside.

2. Replace the battery terminals - using plenty of dielectric grease. Even if they look fine, there can be a thin film or some corrosion that totally boning your conductivity. I've seen this be the cause of electrical issues more times than i can count.

The total cost of these two things is <$10.