Park light/side marker light volatage delimma!!!!

[hokie8358]

Just had gen.2 light come on, so i isolated the gen. And checked with volt meter. Was reading 25.9 on it and 30.7 on driver side! So i had a spare and put it on the pass. Side and rechecked it. Now dash gen. Light is off and checked with volt meter and its pulling 30.9 ! So i pulled my headlights since i just installed new ones and they worked fine. Now my front side markers are not burning as well as my park/signal lights in the front!!! So i took the bulbs out and hit them with the volt meter and touched bout the prongs in the sockets. One side is showing 10.6 volts and the other showing 6 to 7.1 volts. So i checked all 4 of them in the front and its around the same. When i went to put the side marker light in i noticed it was barely burning on the filament! You can hardly see it in the day time! So i am seriously lost on this one!!!
Need a starting point to look at for the under voltage i am assuming!! This is a new one on me!!! As for rear lights there burning great just like headlights!!

 

[Vhyle]

As far as I know, if you're pulling 25v at least on both alts, your driver side alternator is not on an isolated ground. This can cause some serious issues with the charging system.

The driver side alt should be pulling 14v, and the pass side should be about 28v, if I'm not mistaken. I'm new to CUCVs but I think this is correct.

I would correct that problem first and foremost.

 

[2002ford]

Check all of the grounds from front to rear. It worked on my M1008.

 

[1ton cucv k5 turbo]

sounds like you have mulitple issues... As stated above... check you grounds for lights... and recheck both alt... may have a stator or rectifer going out....

 

[cpf240]

As far as I know, if you're pulling 25v at least on both alts, your driver side alternator is not on an isolated ground. This can cause some serious issues with the charging system.

The passenger side alt ( GEN 2 ) *must* be an isolated ground alternator. The drivers side alt ( GEN 1 ) is an isolated alternator in the stock configuration, but this is mainly so that the military only had to stock one part. GEN 1 can be replaced with a standard off-the-shelf alternator without any issues.

The driver side alt should be pulling 14v, and the pass side should be about 28v, if I'm not mistaken. I'm new to CUCVs but I think this is correct.

Yes, this is correct, though I would phrase it as "... should be outputting 14v..."

 

[hokie8358]

ok good deal! i have done some major work to the alternators, and rewiring issue s on this old 1028 to bring it to life!! weather has kept me from getting under the hood though! thanks for the ideas! oh by the way your probably right. i checked the slave cable recept. and it was showing on my volt meter read out at 62.1 volts! so therefore both alters. are crancking out 30 volts apiece!!!! correct

 

[hokie8358]

in between the rain i just checked it,isolated the pass alter. and it was 30.4 and checked drivers side and showing 30.1! so i checked the driver alternator and the ground wire from harness and strap over to head is hooked in there proper place.

 

[Vhyle]

The passenger side alt ( GEN 2 ) *must* be an isolated ground alternator. The drivers side alt ( GEN 1 ) is an isolated alternator in the stock configuration, but this is mainly so that the military only had to stock one part. GEN 1 can be replaced with a standard off-the-shelf alternator without any issues.



Yes, this is correct, though I would phrase it as "... should be outputting 14v..."

Ah yeah, I got them mixed up. Thanks.