Alternator Questions

[Wildman]

If you have a Hanye's manual, there is a way to check the CPS from the top, in the engine bay to check it for OHM's across points A and B, to see if if is defective or not.

 

Your cranking problem could be from the fuel pump back draining into the tank, in other words, the "check valve" on the pump is faulty. You say when you start off down the road, is spits, like it's not getting enought gas, that could also be the fuel pump.

 

That was funny about your testing the new alternator, and forgetting to hook up a wire. Don't feel bad, been there, done that. Is aways the little stupit things we do.

 

Now that the Alternator is fixed, I think your next project is the fuel pump.

 

You can just change out the pump and filter sock alone, or the whole sending unit, you have some time, so check this out-

 

http://www.rockauto.com/catalog/x,carco ... ttype,6256

 

There are two diffrent pumps that Jeep used, I think the Bosch OEM was more popular, that's what I've seen on my MJ's.

 

If you have a Harbor Fright around you, they sell a fuel pump tester for like $8, and it's handy just to have around.

[jtdesigns]

Kinda old thread I know... I'm having a charging issue on this mj I'm messing with.

 

The alternator looks like a gm alternator.

 

 

Is it the same as another vehicles alternator??

 

TIA,,,,,,jt

[deziped]

89 MJ's are charged from alternator to PDC to battery. Not directly from alt. to battery. Thats why you can remove your battery from the circuit and MJ will continue to run w/out battery voltage. Also why sometimes if the fuseable link in the alt to PDC line goes bad you think your alt is shot when its not. Use a multi-meter to see if any voltage is coming out of bat post on rear of alt.. It's easy to get to. My alt died on me yesterday & it was only putting out 0.15 V. Put in Remanf 100A alt & I now have 14.5V across battery w all access & ligts on. :chillin: