Electrical ? on my CJ5 Amp Light On When Key Off

[Randy]

72 cj5 304v8
I just replaced my alternator and rewired it just like I found the old one.

Now the amp light stays on all the time and goes off when I turn the key to the on position.

My battery was running down every couple days I figure the light was probably on before I replaced the alternator. The alternator still checked bad when i got a new one.

Any one know what may be wrong?

[Texasredneck]

sounds like you got a short some where, or might have a wire crossed ...jmo

[Solocam00]

sounds like a crossed wire to me too. are you talking about a speaker amp?

[buffalorider]

Sounds like a bad battery to me. Did you have it tested?




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[hellbndr23]

Sounds like the light wire is in the wrong side if the ignition switch. When the key is off the light get power from the constant hot.

turn key on and electricity go to the ignition system

Not enough juice to do both.

[Randy]

No I didnt test the battery only the alternator. Battery could be going bad its several years old.

There is basically nothing electrical on my jeep other than a tailgate feeder Ive been running.

I can charge the battery and start the jeep a dozen times or so. Then over the course of a few days its dead again. I figure the starter was draining the battery and the alternator wasnt charging it back up.

[Randy]

Sounds like the light wire is in the wrong side if the ignition switch. When the key is off the light get power from the constant hot.

turn key on and electricity go to the ignition system

Not enough juice to do both.

Now that sound about right...Ill dig into this tomorrow. Appreciate the help ag.

[Texasredneck]

just another word of advice, next time your at a part's house pick up a "Chilton's Manual"
they come in handy alot, or at least they do for me. Good Luck.

[Blood Trail]

reverse the polarity on your alternator. You got positive and negative crossed. Easy way to find the ground is to take a meter with the amp hooked up and measure resistance to the chasis and the wires in question. that negative should be tied to ground and read a short (<10 ohms) on the meter. hope this helps...

[bowmech]

reverse the polarity on your alternator. You got positive and negative crossed. Easy way to find the ground is to take a meter with the amp hooked up and measure resistance to the chasis and the wires in question. that negative should be tied to ground and read a short (<10 ohms) on the meter. hope this helps...

Do not change polarity, you are going to do a lot of damage.
Amp light on with key of is either a bad alternator if you have a internal voltage regolator, or a bad voltage regolator, depending what system you have in your jeep.

[bowmech]

i can walk you through this, but i need some supporting diagrams. send me a pm if you need some help. it may take some time, hard to get info on old cars, specially since i do normally only europeans. But do not reverse polarity on either alternator or battery!!!!!!!!

[Randy]

Appreciate the help guys. Im gonna dig into it tonight.

[hellbndr23]

Amp light on with key of is either a bad alternator if you have a internal voltage regolator, or a bad voltage regolator, depending what system you have in your jeep.

I think yall may be going a little deep into this. Dash lights in 72 probably didnt come from the alternator. He said the light was on, not the gauge. If the gauge was reading then yea lets look at the alternator.

You also have to think of how many people have touched the wiring in this thing since 72. Odds are thats not the original ignition and someone didnt pay attention when they took the wires off and put them back on.

[Randy]

The amp gauge showed to be charging when its running.

There is a cluster where your speedo, gas, gauge and there is a red light that says amps thats on when the key is off.

Im thinking Ill use my volt meter and make sure the new alternator is charging. Then just snip the wire that keeps the light on and see if my battery still runs down.

Were talking about an ol hunting buggy that never sees pavement so a little southern engineering is alright.

[Randy]

I think I fixed my problem. Had a nekkid spot in the wire that was grounding out.

Also had a purple small wire that was taped up. Not sure what it goes to but I unwrapped it and hooked it up on the small post on the alternator.

You could tell thats where it goes. Figured its worth a try to figure out what might happen.