Question About A Gm W-400/isuzu Npr

Plumber_Bill

I have a problem which has not affected the running of the vehicle.
The problem is, the dash idiot lights stay on. When the key is turned to on all the lights come on. When engine start occurs they used to go off.
Now the only ones that goes off is oil and glowplug.
Battery, Temp, Vacuum, and low fuel stay on.
Since this problem started a couple of days ago the exhaust brake is inoperative and the green indicator does not come on.

The truck model year is 1993 has 177,000 on the mileage.
I presume that this electrical problem lies some where in the relay bank
The fuses are all OK.

Has anybody encountered this problem? What was the fix?

Bill Parr Allentown, PA

PS Please no sermon on keeping a truck that long.

tedthebuilder

I have the same year Isuzu NPR. My lights came on a couple months ago. I asked the fleet mechanic where I bought the truck about this and he told me the lights come on when it stops charging. I replaced the alternator and the lights are still on. I had no problem with starting until about a week ago. Just today I had the batteries tested because they were low and wouldn't take a charge and was told they were from 1997 and shot. So I replaced them. The lights are still on. I am going to replace the charge relay next. In addition to the lights being on, the heater fan doesnt work. I think its related.

My exhaust brake has never worked because the fleet mechanic in his infinate wisdom, rendered it inoperable when the truck was new.

You wont get any lecture from me about keeping a vehicle too long. Mine has 610,000 miles on it !

HSConstruction

16 yrs old and 600k? The drivers seat must be fabric covered steel frame because all the foam has fallen apart.

__________________

tedthebuilder

After I put a new charge relay in, the lights went off as soon as it started. Also the heater fan works again. Wish I would have known to try this first! Only good part is that I can write it off at tax time.

PS. The seats are in good condition. These trucks were built to last. Like anything, regular maintenance and service plays a big part.


Ted-Lewisburg, PA

Frankawitz

not to be a smart azz But maybe you should have bought a American Made truck I have a 1991 and 1993 Fords the 91 hit 185,650 the 93 is at 179,850 Plus it keeps my neighbors working

Plumber_Bill

OK Ted ... Also the charge relay fixed mine.

THANK YOU!

Plumber_Bill

Ted I replied per the above a couple of days ago. As we have the same truck. Isuzu just sent me a complete PDF file on the relay and fuse block.
Names them all shows what they do and where they are located.

Give me your e-mail address. I'll send it to you.

Mine is parrplumb@enter.net