9665sd

Just bought this 96 f150 xl 4.9, 5 speed stick with 119k on it, runs good, been driving it daily for a 5 weeks, I replaced the plugs cap roter about 3 weeks ago,and yesterday replaced the coil and wires, with some nice Taylor wires and a powerful mad replacement coil. After finishing I went to fire it up and it didn't even pop once, it just turns over. I then checked for spark from the coil wire..Nothing! Checked the fuses under the hood on the black box and there was one big fuse blown, the PCM Relay coil power 20 amp.put the old coil next the the new one and hooked it up, and it started, shut it off right away, made sure the fuses were all good, went to napa and Picked up a new napa coil, and took out the msd coil, installed the new napa coil, and nothing again, and the fuse was blown again. I did remove the battery pos cable every time I put a screw driver to it, when remove/installing the coil.
The coils plug-in, isn't in the best condition, contacts are oxidized from the Minnesota climate., To me, there Must Be A Short in a wire to cause a fuse to blow right away, every time I tried to start it. Anyone know where I should look for a damaged wire, coil feed and back to ?? please help.

Chris_1

iTrader: (1)

It's most probably the plug for the coil.
I hate hearing people say they put a big powerful coil in. In my experience that tends to tax the rest of the system and I don't think it's a coincidence that people end up changing the PIP and ICM shortly after.
The stock coil is dependable in conjunction with the stock ignition system.
Check out easyautodiagnostics.com for troubleshooting how to's.

9665sd

I did buy a replacement last night that I was planning on installing this morning, the original was pretty bad !, just didn't think it would blow a fuse?. The relays that are next to the fuses in the black box. Could one of them be acting up and cause this fuse to blow?

Chris_1

iTrader: (1)

Usually for a fuse to blow it will mean you have a short straight to ground which pulls more power than the circuit was designed to handle.
The fuse is to stop the wires from frying and burning up the truck or cooking electrical components in the circuit.
So something is letting way too much power through if it takes out fuses.

9665sd

I installed the new aftermarket coil plugin, looks the same as the Ford part in shape, but it's material is very brittle!. It turns out NOT to being the problem!. It was anothe factory wire which grounds on the coil bracket below the coil, it kept blowing fuses until I removed it!. Works perfectly now!. I wish I wouldn't have bought that 2nt coil from napa, and just had the New MSD higher output coil tested, that's the one I wanted to use ! But summit agreed to return it so I bought that napa replacement, which is a very nice coil, and at least it's made in Poland rather than China or Mexico. Nothing against Chinese or Mexicans of course.