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1992 isuzu npr troubles - vac, brake, batt light

Posted: Sun Feb 28, 2016 1:11 am
by 9986mkoh
Hi,
I have a 1992 Isuzu NPR chassis in my safari trek motorhome. It has 113,000 miles and is in great condition and worked great up until just after I started it and pulled it out of storage to work on it this winter. First off, I replaced the charge relay and alternator together and it worked - for maybe 15 minutes. Before I throw more time/money at this I would like to get some input as to what to do or look at/test. There is no output from the alternator, batteries do not charge. I've traced wires to verify nothing is incorrect and to the best of my knowledge that is the case. Originally when this showed up, I looked at the alternator and saw that the terminal was ripped/loose so that could cause some problems. However I do not know where to look next.

Thanks for any suggestions!

MIKE

Edit: It is the 3.9 diesel, 4BD2T I believe.

Re: 1992 isuzu npr troubles - vac, brake, batt light

Posted: Sun Feb 28, 2016 5:15 am
by geeves
We dont use that engine in our vehicles because it is a truck not suv engine. However the basics are the same. The charge relay would of been blue or brown. These are voltage sensing relays and must be changed like for like.
If you have the correct charge relay take the alternator to your local auto electrician and he will be able to test it etc