Gen 2 Light, not on or off but really dim? Stays on

[sschaefer3]

Everything was working fine yesterday then yesterday afternoon all of a sudden the gen 2 bulb is no longer on or off, but dimly lit.

Here is what I checked:

Front Battery Engine Running: 14.32 volts
Rear Battery Engine Running: 12.42 volts, (gen 2 is not charging)

Alternator exciter plug:

Key off:

red: 25
B/w: 0

Key on:

Red: 24.8
B/w: 24.5

24V gauge in the cab: 24.8

I did rebuild both gen 1 and gen 2 with the spring hill kits a month ago, I though it was easy and had no problems.

What would cause the bulb to glow dim? It happens when you turn the key on and stay dim with the engine running. Gen 1 comes on bright and goes off on start.

If you unplug the gen 2 prong exciter wires the dim bulb goes off.

Any ideas?

I replaced the 194 bulb on the Gen 2 socket and same thing, dull bulb.

 

[Warthog]

Time to pull GEN2 apart again and check the tri-diode and rectifier.

I had had a few of them fail shortly after a rebuild.

 

[sschaefer3]

10-4, Which of those parts are tri-diode and rectifier? I will just order a new re-build kit and skip re-bearing it. Change the internals again.

Thank you for sharing your experiences.

 

[doghead]

Just look at the pictures of the parts on their website.

 

[doghead]

http://www.steelsoldiers.com/cucv/54292-cucv-alternator-symptoms-diagnosis-fix.html

one of 35 threads that came up with a general search for diode trio.

 

[sschaefer3]

I have ordered all the individual parts from ASP. I will have a stock on hand for any future repairs.

2 x DIODE TRIO
2 x RECTIFIER
1 x CAPACITOR
1 x BRUSH HOLDER ASSY.
4 x REPAIR HARNESS
4 x RESISTOR

Thank you for the help!

 

[M1008driver]

CUCV Electric sells kits too. I have one waiting for me to get bored some day.

 

[sschaefer3]

I have resolved the issue, the truck is now back to normal. I did what was suggested here and it was spot on.

When I pulled the alternator, the wire to the capacitor was broken off, replaced that part. I replaced the tri-diode and rectifier and found the plastic brush holder broken off in the alternator. Luckly I ordered a new one of those. Put it all back together and I have a fully lit Gen 2 light and it goes off when I fire the beast up.

I want to thank everyone who helped me here, you don't know how much I appreciate the advice. Thank you very much.

 

[Warthog]

Glad you got it fixed.

We have been around the block a few times with these trucks.