Trying to repair the alternator

flash7210 · **Posted:** Sun Jan 24, 2016 4:44 pm

Part 1- disassembly

This thing looks pretty easy to refurbish.
The brush holder, regulator, and diodes are all easily accessible without much work.

Three nuts hold the plastic cover on the back. Remove the cover and in the center is the brush holder. The brush holder is screwed into the voltage regular which is easily identifiable by its aluminum heat sink.
The voltage regulator is held in by two screws and it has a tab that is crimped to a copper lead from the diode pack.
That tab was crimped on pretty tight. Not wanting to break the copper lead, I carefully cut the tab off the regulator.

Diode pack has 12 diodes.
6 on the outer circumference and 6 on the inner circumference.
It is held in with 4 screws and it looks like the six leads from the stator windings are brazed to the connections on the diode pack.
Thankfully, all the diodes tested good so I wont be replacing the diode pack.

I have a new regulator and brush holder arriving this week and I hope to have this put back together and tested next weekend.

Pictures...

Mike92104 · **Posted:** Sun Jan 24, 2016 10:34 pm

Where did you find your alternator parts? Mine is beginning to flicker, and I'd like to refurbish it rather than get a reman.

Mike

flash7210 · **Posted:** Sun Jan 24, 2016 10:43 pm

eBay.
Found a listing that included the regulator and brush holder for under $50.

Mike92104 · **Posted:** Sun Jan 24, 2016 10:50 pm

Sweet. Did you search by part number or vehicle?

flash7210 · **Posted:** Sun Jan 24, 2016 10:54 pm

I searched "liberty diesel alternator"

racertracer · **Posted:** Tue Jan 26, 2016 2:01 am

Here is a Youtube video on how to repair your Denso alternator.

https://www.youtube.com/watch?v=LqvTHJVQU5g

flash7210 · **Posted:** Sun Jan 31, 2016 3:18 pm

Part two:
Installing new regulator and brush holder.

flash7210 · **Posted:** Sun Jan 31, 2016 3:27 pm

Part three:
Testing

Before I made the repair I noticed that the alternator worked just fine without the regulator wire plugged in. Now, with a new regulator, the alternator would not charge at all until I plugged in that regulator wire.
Probably just a capacitor in the regulator that needed to be charged before it would become operational. None the less, I found it interesting.

Anyway, so far so good.
No flickering lights and no dimming. Charging at 14.04 volts.

If any of those symptoms return or anything else wierd happens, I will update this thread.

jws84_02 · **Posted:** Sun Jan 31, 2016 4:13 pm

Prolly a mute point but mine typically charges 14.6-.8 in cold conditions. Could just be a "weaker" battery initially if you had charging problems before

taroo · **Joined:** Sun Apr 27, 2008 2:14 pm **Posts:** 276

flash7210 wrote:

Part three:
Testing

Before I made the repair I noticed that the alternator worked just fine without the regulator wire plugged in. Now, with a new regulator, the alternator would not charge at all until I plugged in that regulator wire.
Probably just a capacitor in the regulator that needed to be charged before it would become operational. None the less, I found it interesting.

Anyway, so far so good.
No flickering lights and no dimming. Charging at 14.04 volts.

If any of those symptoms return or anything else wierd happens, I will update this thread.

So, my lights have been flickering and and dimming for some time now. Are you saying that can be rectified (ha...get it) by changing the voltage regulator?

flash7210 · **Posted:** Sun Jan 31, 2016 10:46 pm

Idk if its the regulator or the bushes. They both came in the box and I installed them.
It will probably take a weeks worth of driving to be sure that the problem has been fixed. It was very intermittent.

Trying to repair the alternator

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