1990 k5 ecm fuse blows after fuel pump installed
 

Fuse blows with ing. off any ideas

was this happening before you did the pump, are you sure the pump was the issue, could have been the fuse the whole time?
only thing i could think of that would have to do with both is a ground some where.

No the fuse wasnt blowing before. However I pulled the battery & charged it because it went down for some reason. So I took off the breather and found the electronic control spark module and replaced it for $77.00 figured it cant hurt so for now it will start & run real good but I have not road tested it yet. Oh yeah the check engine or service engine soon light is but its been on before?

When I replace the fuel pump I had to replace the relay Fuse on the firewall on the passenger side. this fuse may still work but may cause the fuel pump to grown out. Second on the frame of the driver side make sure the grown is connected all the way. The reason I say that it may come lose due to off road. You may want to reconnect the grown to somewhere in the engine compartment.