• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

lights pulsing

90xj06

NAXJA Forum User
Location
Peabody, MA
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.
 
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?
 
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.



Doing this is a good idea.
 
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.
 
Back
Top