Hi all, so I have this generator light on as soon as I got the vehicle delivered. PO showed videos of driving the vehicle just before sale without this light on. Either I trust the PO or something happened during long distance shipping. Something may have come lose. I am going to get it all checked out on Tuesday by a mechanic but thought I would share the video below to see if anyone has any ideas.

I have done the alternator test. The voltage does increase as I rev the engine but only slightly. At idle it hovers around 12.6V.

On idle the G light is bright. As I rev the engine it dims a little and as I release the gas pedal to bring it back to idle the light returns back to bright red.

Thanks for providing any guidance.

https://vimeo.com/520378331

check grounds

Any specific areas of generally overall?

Thanks.

Can you provide details on the alternator test you have done?

If you haven't yet, do these tests:

1) Check the alternator belt to make sure it's tight.

2) With engine running, measure DF, D+, and D- at the voltage regulator (VR) connector on the relay board. Measure these signals to chassis ground lug behind the relay board. Do not measure from engine tin or case. Also measure the battery voltage as well

3) To check the alternator, with engine off, remove the voltage regulator from the relay board and short the DF and D+. Start the engine and measure DF to chassis and battery voltage.


Click to view attachment

Turns out I need a new alternator and these are apparently tough to find in Ontario/Canada. Would anyone have any suggestions?

Thank you!

https://allzim.com/index.html

Contact Arron ( @partsguy22 ). They can ship you a rebuilt alternator.

Clay

Thank you - appreciate that and will get in touch with them.

Tell Aaron I sent you.

Clay

Thanks Clay - sent a note off. Appreciate that.

A bit more follow-up before I see the mechanic this week. I connected a bluetooth monitoring on my battery. Here is a video. https://vimeo.com/523472269

Idle I'm sitting at 12.65 volts. As you can see after I start driving the voltage goes up slightly. In 3rd gear (driving around my neighbourhood I couldn't get it past that) the battery voltage increase to about 13.3v. Looks like the battery is providing that voltage. What does this tell me? Could the alternator be fine? Not charging as well (possible belt tightening)?

Voltage change with a properly-woprking alternator should be RPM-based, not load based, so you should be able to replicate that in neutral by revving the engine.

If you're seeing more than resting voltage with the engine running, then your alternator is putting something out. May not be full amps, but it's something.

Is the GEN light still on when you're seeing 13.3V at the battery?

Did you do the tests that Spoke listed above?

I'm still seeing the Generator light and it fades a little when I rev up the engine. I performed the DF to D+ short test and the voltage didn't change from the resting voltage.

I *think* this is the same thing. I'used this to troubleshoot an alternator. If it fails these tests then it's the alternator; if not then it's the voltage regulator or wiring.

https://www.pelicanparts.com/techarticles/9...roubleshoot.htm

If you're *truly* getting 13.3V at speed, then it's charging the alternator. Much less than that then you're not.

Note that the GEN light works on differential voltage. On one side is the D+ output voltage and the other side is the battery. If the voltage differential between the two is zero (as it should be) then the alternator voltage matches the battery voltage and the GEN light is off. But when the alternaotr fails and the D+ voltage is to ground, then the differential is the battery voltage and the GEN light turns on.

If you are getting a generator light that fades with an RPM increase, and you can see charging voltage, even if it is low, then you have a bad diode in the alternator.

The reverse voltage pulse causes the light to come on, even if the alternator is charging. You would need an oscilloscope to verify the bad diode.

I would suggest a new alternator.


Aaron told me he talked to you, and you were going to get the alternator rebuilt and replaced locally because it wasn't feasible cost wise to ship one to Canada.

Good luck!

Correct. Thanks Clay. I’m seeing a mechanic later this week to get it rebuilt. Thanks for your help.

Isn't this a great place? SO much help and knowledge. Good luck with the rebuild.

Fucking love it. Thanks all - I've been here for about a month and have gained years of knowledge.

Just wanted to send an update and confirm some suspicions by you lot.

So it turns out it was a bad diode in the alternator. The shop confirmed this. They are going to rebuild the alternator while they've got it out and change what they deem necessary.

Thanks everyone.