Gen 2 alternator replacement question

[Pzkw88]

Hi, I'm installing a new alternator in the gen 2 position and I noticed that my truck does not have the black wire with push plug for the small stud. What was this wire for and where does it go? Any help would be appreciated. It's a 1985 M1009 army that transferred to the navy in the 90s.

 

[txmytx_catahoula]

Check out the "alternator symptom" sticky (post 120) in the CUCV forum. That location is only used on the driver's side alt. It's tach pick up as part of the STE/ICE diagnostic system.

 

[Pzkw88]

Thanks ill do that. I just found I don't have power at my gen 2 light socket. Checked the exciter wire and it has some funky diode or resistor inline that I don't know how to tell if it's good. Guess ill keep searching. Thanks again.

 

[cpf240]

Post pictures of the wiring on the alt, etc. If that really is a resistor on the exciter wire plug, perhaps someone bypassed the dash light.

 

[Pzkw88]

Ok I'll work on the pictures. I tried bypassing the component that's inline on the exciter and when I do that the gen 1 light glows with the key off and the low coolant light is on too. I'm not sure what some genius did or why but it's causing a headache. Here's what I do know, when the key is on the gen 2 relay clicks and running voltage between the batteries is 27-28v. The truck belonged to Naval Facilities Engineering so who knows what other surprises are lurking about.