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Rainman 09-22-2009 04:10 PM

Voltage problem????
I have a voltage problem with my 1990 YJ. It has a 2.5L and 5 speed. The voltage keeps going up and down like from 8 to 18 volts. I have changed both battery cables, had the alt. checked on and off the Jeep. I also cleaned the ground spot from the battery and wiring harness and the one going from the intake to the tub and it is still going all over. It is a southern Jeep that has never seen road salt. Any help would be cool. Thanks in advance.

NAVYCHIEF 09-22-2009 04:13 PM

i took my alternator apart and cleaned the armature and brush faces. re-assembled and it has worked fine for 6 mos now.

Rainman 09-22-2009 04:20 PM

I took it in to the shop and had the alt. pulled apart cause the power stud coming out of the back was loose and they fixed it and tested it again. It was charging good.

minderbinder3 09-22-2009 04:27 PM

Is it just your gauge telling you that or are you testing the battery with a voltmeter? Jeep gauges are notorious for bad readings.

morphious 09-22-2009 04:33 PM

uh huh yes they are i have to hit mine every two days to get it to work

Rainman 09-22-2009 04:35 PM

I will be checking the voltage with a meter in a little bit. My son is bring it over. When I had everything tested on the jeep it was showing all over too. but I will be testing it soon. Does the 90 YJ have a computer?

morphious 09-22-2009 04:41 PM

Yes it does but its primitive, and i suggest that u bypass it it. Helps a ton its called the nutter conversion

Rainman 09-22-2009 04:55 PM

What is a nutter conversion? and how do I do it? :banghead:

Cons_Table 09-22-2009 05:02 PM


Originally Posted by Rainman (Post 446221)
What is a nutter conversion? and how do I do it? :banghead:

I read about this some here

The "Nutter" Bypass

someone of more knowledge may be able to tell u if this is correct

Rainman 09-22-2009 06:50 PM

I just checked the voltage with the Fluke multimeter and at idle it is just over 14 volts and when I rev it up the voltage goes up? Is there a short or should I do that nutter conversion?

NAVYCHIEF 09-22-2009 07:02 PM

what happens if you remove the battery neg term while the engine is running?

Rainman 09-22-2009 07:26 PM

The motor still runs fine if I unhook the battery. Since I repaired the alt. the voltage is not dropping and a little bit ago I washed off a little mud from under side before I left my parents house and the volt meter did not jump up right away but I was only washing along the sides.

hiram 09-22-2009 08:35 PM

check voltage regulator

Rainman 09-22-2009 09:12 PM

It has an internal voltage reg..

Rainman 09-23-2009 06:14 PM

Does anyone have any other idea's?

NAVYCHIEF 09-23-2009 06:43 PM

maybe check the pulley. is it tight? it sounds kinda like the alternator speed could be varying and not running at a constant speed. or the belt too loose/tight?

Rainman 09-24-2009 09:06 AM

The pulley is tight and the belt is good.

Rainman 09-24-2009 11:06 PM

Well after it tested good on the bench 2 times but did work right on the Jeep I have changed the alt. and it is working fine now. Thanks for all your help. :)

morphious 09-25-2009 06:49 AM

just pm me if u still want the nutter conversion help. i just did this a month ago

Rainman 09-25-2009 06:04 PM

What else does the nutter conversion do? Does it help it run better or anything else?

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