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90xj06
November 19th, 2017, 16:17
I noticed this the other day. at least at idle my dash lights and interior lights pulse. the interior lights are led but the dash lights are still incandescent.

Alternator and battery are 1 year old. anything i should look at. i have added an additional battery to frame ground.

techno1154
November 19th, 2017, 19:08
I noticed this the other day. at least at idle my dash lights and interior lights pulse. the interior lights are led but the dash lights are still incandescent.

Alternator and battery are 1 year old. anything i should look at. i have added an additional battery to frame ground.

When my XJ did that the regulator was the culprit. What regulator are you using?

90xj06
November 20th, 2017, 05:11
i believe it is in the alternator. i forgot to list it is a 1988 with the 4.0

cruiser54
November 20th, 2017, 05:34
i believe it is in the alternator. i forgot to list it is a 1988 with the 4.0

ever done this?

http://cruiser54.com/?p=110

techno1154
November 20th, 2017, 08:35
i believe it is in the alternator. i forgot to list it is a 1988 with the 4.0

Actually, the regulator is in the PCM.

My XJ did that because I disconnected the PCM regulator from the alternator and installed an external regulator which was adjustable in an attempt to increase the charging voltage up to 14+ volts. I have since reverted to the PCM based regulator.


ever done this?

http://cruiser54.com/?p=110

Doing this is a good idea.

JeepNoob
November 22nd, 2017, 09:12
If you've got a multimeter that does it, check for AC voltage (NOT DC!!!) between the alternator output wire and a good ground such as the alternator case with the engine running. Any AC voltage coming and going from the alternator probably indicates that a diode in the alternator has gone bad.