87 K5 keeps blowing ECMB 10amp fuse

[1987 K5 Blazer]

I have an 87 K5 blazer, wnt to start it yesterday and crank but no start, thought it might be fuel filter so changed it out. Noticed the ecmb fues was blown replaced it and it blew as soon as i turned the ignition on. changed out the fuel pump thinking that might be the issue. Still no start and smelled electrical wire burning from behind glove box where ECM is. Pull down a glove box put a new fuse in went to start the truck and saw a puff of smoke. Any ideas would help. Thank you in advance.

 

[OzarkRunner]

I had that issue with my '90 Suburban a year or so ago. Mine was a short in the wiring near the fuel pump - I'd start there.

 

[RoryH19]

My thought as well. You are grounding out somewhere in the power lead for the pump. Look for any pinched or frayed wires.

 

[1987 GMC Jimmy]

Check for heat stressed wires around the exhaust manifold and engine block that maybe rubbing up against metal and shorting to ground. That was more of an ECM-I issue for me, but I think it’s still worth a look. I’d also check the 1987 MY electrical supplement and follow what’s tied to that fuse. That’ll help narrow down your options.