I have 1991 f150 5 speed manual. I trying to replace the ECM. I went under the hood and tried to disconnect the plug on the firewall. The 10mm bolt don't come out completely however, the plug will not come out no matter what I do. Do anybody came across this problem before? This suppose to be a plug and play type deal.

 

Welcome, is there not a hold down piece of plastic that must be lifted/released first, then the plug will come out?

 

Nope just a single 10mm bolt. It suppose to just pop out. But nope, it stuck. It the firt time that it have been touched since it been manufactured.

 

Well, first thing I would do if you have not already, is disconnect the battery. Then I guess maybe some electrical connection cleaner???

 

will give that a try. I wonder why it's like that.

 

Hopefully not corrosion!

 

I hope not. Because that thing feels like it welded to the cpu

 

It "is" just about plastic welded together
You go around the connector with a pocket screwdriver and get it broken loose from the ECU case plastic on its connector part
Once you get it to wiggle you will be able to pull it out
Think like a Gorilla or King Kong and pull real hard

 

Note taken, lol now I know my ECU is jacked. I just need to be careful. I dont wanna replace a harness, or hardwire an new ecu plug.

 

It's sorta like our old trans man who listened to country music when we all wanted rock
We would change his station to Z rock and spray the **** with brakleen
That would stick the **** like woo wee
He would just about have to break his radio to get some country back
Your processor, if anybody ever cleaned the master cylinder off with brakleen will do the same thing
Like the GM Transmission Range sensors, you just about have to break the "glue" off before you can break the connection
Just go slow and easy with the pocket screwdriver around that rectangle