Hi All
I'm a newbie here. I searched the threads for my problem but didn't find any answers so....
My PCM diode fuse keeps blowing and won't let me start. Going on for about a year now and replacing the fuse has always fixed it but now that doesn't help. Fuse keeps blowing and no start.
I replaced the PCM and it started right up and ran fine but after about 10-15 miles it died on me going down the road. Blown fuse again. I checked for codes and I get zero codes.
I'm thinking this is a short somewhere but I'm not good with electronics.
Any ideas on what I might look for are appreciated.
thanks
Mike
FYI I have 98 xlt 4x2 3.0 No PAT system
I looked at the #8 PCM relay and the #6 PCM in the power distribution box but both of these fuses are enclosed and I can't tell if they are good or not.

 

I switched the RABS diode with the Electronic Engine Controls diode and it started right up but I am not optimistic since I have started in the past only to blow the #19 fuse again. Local parts places don't have the diode so I ordered a couple online. My multimeter hasn't been used in years and I don't think its working so I can't test.

 

Your multimeter may only need a battery. There should be either a door to a battery compartment or screws that will allow you to split the case and access the battery. You’ll need this to find your short.

 

I switch the diodes back and figured if one was bad it wouldn't start again but seems that both diodes are good. WTF? Its running now I'm afraid to take it out. I don't need another tow home.

 

thanks but I put a new battery in and it didn't help. It lights up but doesn't give me a reading on anything including new batteries I have in the drawer.
I just switched the diodes back and truck is starting with either diode so I'm guessing they're good and my problem is something else.