I need some advice. I am an auto mechanic but have no experience with trucks or diesels basically at all. I had a guy who operates a small fleet mechanic service for some bread trucks. All are Isuzu NPR. Around 2014ish. So originally this truck is having the issue of the tail lights, license plate light, and all top lights not working. They will sometimes come on and flicker a bit and then go out after a minute or two. The brake lights and turn signals all work. Headlights work fine. Dash lights work fine. The wires in the back have all been. Cut out and replaced with larger gauge wires. This guy wanted to maybe hire me to work for him and was using me being able to figure this light situation out as a test. Unfortunately I just could not figure it out on a 2 hour span. He has no wiring diagrams. I was pretty sure I isolated which wore went to the tail lights before being t'd off for each side. But was unable to confirm power there. I checked continunity between sections of wore and before and after 2 connectors. I was guessing there was a possible weak spot in one of the wires but I did not want to go tearing into the harness too deep without a diagram. This kinda upset the guy. He said "well we never needed a wiring diagram before!". Before I did this I checked the fuses in the cab. The location you showed. I wasn't sure the orientation of the way the fuses were labeled from the sticker. Looking one way it would appear the tail light fuse was missing. Looking the other way it was an ecm fuse. All I did was pull the ecm fuse out apparently and put it in a socket that had nothing. Then realized this and switched it back. After I did all I was comfortable doing and told the guy to go any further I need a wiring diagram he gets in and starts the truck. Then claims the exhaust light is on and that it wasn't on before I touched anything. I figured that it could be possible when I removed that ecm fuse that maybe it set this code. He then tells me his scan tool will not even clear codes on these trucks… Now I have to meet the guy tomorrow and bring my scan tool and hopefully reset this thing.
My question is is it even possible I messed something up doing what I explained? Shorted something out? It has a code. (Not sure number) but relating to reductant control module. Maybe P20c9? Not sure though. And that exhaust light is on. I don't see how back probing a couple tail light circuits and removing and reinstalling an ecm fuse would cause this. But was hoping for advice.
My truck has the same lights on,,,the relay clicks,,my brake lights work,, I have 12v power at the abs pump,, but the light stay on at the dash and my traction control and abs is still disabled….when I turn the key to ignition on,,you can see the abs light comes on green,,then changes to orange after a few seconds…when I hook up my scan tool,it doesn't see the abs module any at all…where do I check next, as I'm unable to read a code…is there a way to check codes without the scan tool? Its a 2009 elf /npr, 4hk1 ,automated shit
If my brake lights are still working could the switch be bad? My ABS and Brake light just came on my 08 NPR after a tire change. Inspected everything not sure if the tire guys broke anything. Checked fluid reservoir, checked rear tires to see if they damaged stud or broke a flange, nothing. Fuse is fine.
Hello Npr doctor. I am having a problem with my 1999 npr. My emergency lights and breaks work but when I signal nothing comes up in my dash nor my lights blink. I thought it can be a relay ? Or turn signal switch ?
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I need some advice. I am an auto mechanic but have no experience with trucks or diesels basically at all. I had a guy who operates a small fleet mechanic service for some bread trucks. All are Isuzu NPR. Around 2014ish. So originally this truck is having the issue of the tail lights, license plate light, and all top lights not working. They will sometimes come on and flicker a bit and then go out after a minute or two. The brake lights and turn signals all work. Headlights work fine. Dash lights work fine. The wires in the back have all been. Cut out and replaced with larger gauge wires. This guy wanted to maybe hire me to work for him and was using me being able to figure this light situation out as a test. Unfortunately I just could not figure it out on a 2 hour span. He has no wiring diagrams. I was pretty sure I isolated which wore went to the tail lights before being t'd off for each side. But was unable to confirm power there. I checked continunity between sections of wore and before and after 2 connectors. I was guessing there was a possible weak spot in one of the wires but I did not want to go tearing into the harness too deep without a diagram. This kinda upset the guy. He said "well we never needed a wiring diagram before!". Before I did this I checked the fuses in the cab. The location you showed. I wasn't sure the orientation of the way the fuses were labeled from the sticker. Looking one way it would appear the tail light fuse was missing. Looking the other way it was an ecm fuse. All I did was pull the ecm fuse out apparently and put it in a socket that had nothing. Then realized this and switched it back. After I did all I was comfortable doing and told the guy to go any further I need a wiring diagram he gets in and starts the truck. Then claims the exhaust light is on and that it wasn't on before I touched anything. I figured that it could be possible when I removed that ecm fuse that maybe it set this code. He then tells me his scan tool will not even clear codes on these trucks… Now I have to meet the guy tomorrow and bring my scan tool and hopefully reset this thing.
My question is is it even possible I messed something up doing what I explained? Shorted something out? It has a code. (Not sure number) but relating to reductant control module. Maybe P20c9? Not sure though. And that exhaust light is on. I don't see how back probing a couple tail light circuits and removing and reinstalling an ecm fuse would cause this. But was hoping for advice.
My truck has the same lights on,,,the relay clicks,,my brake lights work,, I have 12v power at the abs pump,, but the light stay on at the dash and my traction control and abs is still disabled….when I turn the key to ignition on,,you can see the abs light comes on green,,then changes to orange after a few seconds…when I hook up my scan tool,it doesn't see the abs module any at all…where do I check next, as I'm unable to read a code…is there a way to check codes without the scan tool? Its a 2009 elf /npr, 4hk1 ,automated shit
If my brake lights are still working could the switch be bad? My ABS and Brake light just came on my 08 NPR after a tire change. Inspected everything not sure if the tire guys broke anything. Checked fluid reservoir, checked rear tires to see if they damaged stud or broke a flange, nothing. Fuse is fine.
Can you do a video on bleeding air in powersteering?
Hi mate my NPR had ASR light on do you know what’s the problem please? Thanks
Would you happen to know what fuse it is for the cigarette lighter? 2007 npr ?
Hey doctor,
Any idea what’s going on with my npr when I turn it on it buzzes for a solid 3 seconds
Hello Npr doctor. I am having a problem with my 1999 npr. My emergency lights and breaks work but when I signal nothing comes up in my dash nor my lights blink. I thought it can be a relay ? Or turn signal switch ?
Any way you could make a vid on replacing a floor board? I got a huge hole in the wood on one of my floor boards in the box
Heroe npr great videos