No tach, no charge. Is it alternator?

OT · Apr 17, 2004

I ran in a mud bog today and sometime during my first pass my tach went out. That was the only problem all day. (I thought)

I made three more passes and parked it.

After it was all over I loaded up the kids and headed to the river to wash the XJ off. However I only made it a few blocks and had to head to the house.

The problem was the alternator (?) was dead and the engine was running off of battery power only.

Got it home and sprayed off the engine and alternator, but my multimeter still showed no charging.

I think it's the alternator, but is the tach related to the it? I figure the initial splash of mud was enough to do in the alt., but the tach?

What's it sound like to y'all?

8Mud · Apr 18, 2004

Split the case and and wash out the inside of the alternator. Or wash it out as good as you can, with it still in one chunk, if you don´t feel comfortable taking it apart. Have to get inside, in the rear by the brushes, through the air vents. Almost gonna have to remove it, to clean it well.
Could have fried something, but I´ve often seen the brushes, crammed full of mud, so they don´t make contact with the slip rings.
I´ve washed mine out with a solvent sprayer filled with, almost boiling water and a little dish washing detergent. Then blown dry, with compressed air. With seemingly no ill affects.
Might want to check the plug by the igniton coil/module, thats where the tach. wire originates (GRN). Then check most all of the connectors in the engine compartment for moisture.
With some cardboard (as a pattern),some sheet metal, bending and fitting, I fabricated a mud shield, that covers most of the bottom of the alternator. Works better than the stock composite mud guard.
If you have a pre 91, with the Delco alternator, you can mark the case, remove the three bolts and pull the front cover and rotor out, leaving the field winding and rear case together. The three bolts often come out hard and can be snapped off (tap the heads hard with a small hammer, use a penetrating oil on the threads). A paper clip to hold the brushes out of the way to reassemble. Chiltons has a pretty good how too, on R&R of the Delco.
Starter may also require some mud removal, worth a look anyway. A thorough cleaning of the underbody, with special attention to brakes, any seals for rotating parts, radiator and greasing anything that has a zirk, will save maintenance costs later.
If your gonna do any more bogging, think hard about relocating the intake for your air cleaner.
P.S. take a look in the distributor. :rattle: Ain´t mud fun?

tarheel99 · Apr 20, 2004

Don't know if the '92 had a splash shield (my '99 did - rotted and falling apart when I got it - new one was <much better> quality) but this is exactly the kind of mess the shield should prevent. If you get the alternator going again (good luck...) you might want to get one (about $30) before you head for the mud again.

OT · Apr 24, 2004

8Mud said:
Split the case and and wash out the inside of the alternator. Or wash it out as good as you can, with it still in one chunk, if you don´t feel comfortable taking it apart. Have to get inside, in the rear by the brushes, through the air vents. Almost gonna have to remove it, to clean it well.
Could have fried something, but I´ve often seen the brushes, crammed full of mud, so they don´t make contact with the slip rings.
I´ve washed mine out with a solvent sprayer filled with, almost boiling water and a little dish washing detergent. Then blown dry, with compressed air. With seemingly no ill affects.
Might want to check the plug by the igniton coil/module, thats where the tach. wire originates (GRN). Then check most all of the connectors in the engine compartment for moisture.
With some cardboard (as a pattern),some sheet metal, bending and fitting, I fabricated a mud shield, that covers most of the bottom of the alternator. Works better than the stock composite mud guard.
If you have a pre 91, with the Delco alternator, you can mark the case, remove the three bolts and pull the front cover and rotor out, leaving the field winding and rear case together. The three bolts often come out hard and can be snapped off (tap the heads hard with a small hammer, use a penetrating oil on the threads). A paper clip to hold the brushes out of the way to reassemble. Chiltons has a pretty good how too, on R&R of the Delco.
Starter may also require some mud removal, worth a look anyway. A thorough cleaning of the underbody, with special attention to brakes, any seals for rotating parts, radiator and greasing anything that has a zirk, will save maintenance costs later.
If your gonna do any more bogging, think hard about relocating the intake for your air cleaner.
P.S. take a look in the distributor. :rattle: Ain´t mud fun?

That was exaxctly it. Thanks for the tip.

Now to get to work on that shield.

No tach, no charge. Is it alternator?

OT

NAXJA Forum User

8Mud

NAXJA Forum User

tarheel99

NAXJA Forum User

OT

NAXJA Forum User

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