battery getting weaker

[batman02]

Just today my Cherokee's battery started becoming weaker with each successive start of the engine. I got home after dark, but looked under the hood for a possible loose wire but didn't see any. I have set it on a 2 amp trickle overnight so it'll start in the am.

1. How do I isolate that it is the alternator? I also assume it may be a short as it just started today.

2. How do you get to that alternator? It's under the a/c compressor! Does all that have to come out to get the alternator out?


Thanks!

Steve

[89ltd]

use your multi meter to detirmin that the alt is charging, it should read about 13 to 14.5 volts while it is running. You could bring your battery to a store and have it tested for free.

[batman02]

Originally Posted by 89ltd

use your multi meter to detirmin that the alt is charging, it should read about 13 to 14.5 volts while it is running. You could bring your battery to a store and have it tested for free.

Thank you for your reply. I would do what you said but I have never learned how to use a multimeter, although I do have one. What setting would it need to be on and do I just touch the leads to the pos and neg battery terminals?

[Po Pilot]

Set it to 20 volts DC and touch the black probe to the negative and the red probe to the positive. Will tell you immediately what your voltage is.

[batman02]

Originally Posted by Po Pilot

Set it to 20 volts DC and touch the black probe to the negative and the red probe to the positive. Will tell you immediately what your voltage is.

I appreciate your help very much. I think it must be the alternator, because yesterday on the way home, the amp guage was at around 10 and today on the way in about 14.

Steve

[Po Pilot]

Sounds like the recitifiers are going out. Just as cheap to go get a new alternator and put it in.

[badron]

Check batterie(s) water (if it lets you). LOW or NO maintenance batteries are so under "normal condition." If you have and use a winch or plow lift a lot. This is out side what is consider normal. So check the water.
Fully charge battery with cables off. Remove suffice charge by using head lights for 1 min or so. (key off) Remove cables. Check battery voltage. Replace if not up to specs.
Check battery cables and clamps go ahead and clean the posts and clamps.
Check Alt wires for tightness and fitness
Check Alt belt for slack and or cracking. Tighten or replace as needed.
Start engine and let warm. Place full load on alt. All lights, ac blower, big amps if you got, etc. Rev and hold engine at 2000 RPM or so. Then check Alt voltage. replace if needed.
Special Note: If your running lots of extra lights and big amps the alt !!!!!!!!!! MAY!!!!!!!
need upgrading. luck

[batman02]

Originally Posted by badron

Check batterie(s) water (if it lets you). LOW or NO maintenance batteries are so under "normal condition." If you have and use a winch or plow lift a lot. This is out side what is consider normal. So check the water.
Fully charge battery with cables off. Remove suffice charge by using head lights for 1 min or so. (key off) Remove cables. Check battery voltage. Replace if not up to specs.
Check battery cables and clamps go ahead and clean the posts and clamps.
Check Alt wires for tightness and fitness
Check Alt belt for slack and or cracking. Tighten or replace as needed.
Start engine and let warm. Place full load on alt. All lights, ac blower, big amps if you got, etc. Rev and hold engine at 2000 RPM or so. Then check Alt voltage. replace if needed.
Special Note: If your running lots of extra lights and big amps the alt !!!!!!!!!! MAY!!!!!!!
need upgrading. luck

Thank you for your response. I really think you may be on to something as to a loose wire. I had a guy pressure wash oil off the bottom after I repaired an oil leak. The problem started shortly thereafter.

Thanks again!