Gen 2 light

[aaron1009]

My Gen 2 dummy light hasn't lit since I've owned my truck. I have searched for threads regarding this and have come across a couple very helpful ones. When I started checking voltages, I found that my passenger alternator was not plugged in (the two lead plastic plug), and instead had a rubber capoff in place. I also found that there was no relay at all plugged in under the dash. I took the relay from the voltmeter and plugged it in the Gen 2 socket and still have no Gen 2 light. I know the bulb is good, and I'm having a lot of problems trying to get a reading from the bulb socket. The 10amp fuse is also in good condition.

When testing voltages, I found 28ish at the passenger alt (unplugged), and 14 on the driver's side.

I feel I am in over my head when it comes to wiring, so I plan on taking it back to the dealer to have him look over it but thought I'd post here first. Is it normal to have the passenger alternator unplugged?

 

[Warthog]

Sounds like someone has disabled the Gen2 system.

I would check ALL the Gen2 wiring before you start hooking things up.


The easiest way to check the Gen2 wiring is to disconect the 2 wire plug at the GEN2 and check the voltage at the two wires.

In a stock system, the red wire should have 24v at all times.

The brown wire should have 24v only when the key is in the RUN position.

If you don't have these readings, then you will back trace the wiring from the alternator to the 24v in the fuse box.

This has been covered many times in resent past, by me and others.

 

[Wolf.Dose]

Are the fuseable harness at the dash at the 12V connector in good condition(the blue lines at the rear most to the dash)?
Wolf

 

[aaron1009]

Warthog:

Yeah, it looks that way to me as well. The truck has been running fine without Gen 2 (of course) so I'll unplug the alternator just in case. The voltages from both wires are as you describe them, but still no light. It is worth noting that the circuit board at the Gen 2 connection isn't in the best shape, but I strongly doubt it's bad enough to not make a connection.

Wolf:

I'm not really sure what blue lines you are referring to.

 

[Warthog]

If the voltage is correct at the two wire plug at the alternator then the circuit is fine. The issue is the altenator itself.

If the drive side alternator is the same you can switch them to see if the problem follows the alternator.

You can rebuild the alternator yourself for under $40. Step by Step instructions are in the TM 9-2320-289-34 manual.

 

[aaron1009]

While the engine is running I'm getting 28 volts from the back of the passenger alternator, and only 14 or so from the driver's side. Is this still indicative of a problem?

If I'm reading correct voltage from the Gen 2 circuit at the plug, then is it safe to assume that the only issue for my light not coming on is the connection at the bulb socket?

Thanks for the replies all!