1990 4.0 swap help

[Deamers87ford]

i been working on wirering and when i hook battery up my instrument panel like shorts out and clicks and light for check engine comes on and stays on without keys it and if i put keys in the igntion i cant turn them whats going on how do i fix it?

 

[multiranger]

i been working on wirering and when i hook battery up my instrument panel like shorts out and clicks and light for check engine comes on and stays on without keys it and if i put keys in the igntion i cant turn them whats going on how do i fix it?

What year is the truck?
What year is the 4.0?
What motor came in the truck?
what wiring harness are you using? list all harnesses
any other info you think is important let us know?
I think I know what your issue is but Answer the above questions and I'll let you know if it is what I think it is

 

[Deamers87ford]

truck is a 90 4.0 is a 90 truck was originally a 2.9 im using the 4.0 engine bay harness an computer

 

[Deamers87ford]

also im usin the 2.9 5spd trans the 4.0 had auto to it originally

 

[multiranger]

truck is a 90 4.0 is a 90 truck was originally a 2.9 im using the 4.0 engine bay harness an computer

Try unplugging the door light switch wiring on both doors and see what it does
Mine did the same thing but my truck was a 1990 and the wiring and motor was a 92... you may have a late 90 and the wires may be different... if so you will need the correct harness for the doors.. and be prepared to pull the dash.

 

[Deamers87ford]

alright ill see what it does ill let ya know thanks for helping me out

 

[multiranger]

alright ill see what it does ill let ya know thanks for helping me out

That's what we are here for bud! good luck Sir.

 

[Deamers87ford]

hey i was looking at my wirering and i missed 2 plugs coming from the inner fender to about where headlights are on both sides what plugs into these?

 

[multiranger]

hey i was looking at my wirering and i missed 2 plugs coming from the inner fender to about where headlights are on both sides what plugs into these?

If you can take a pic of them and post it.. I can tell you what it goes to if I see it... come to think of it I bet you are talking about the speaker wires.. they are two wires and the connector is round... the door speaker wires run from the front by the headlighs down the inner fender (behind the fender) and into the door... It's stupid how Ford did it I know...

 

[multiranger]

did you try unplugging the light switches?

 

[Deamers87ford]

not yet havent worked on it yet tomrrow i will i work till close tonight

 

[Deamers87ford]

how do i disconnect them?

 

[multiranger]

how do i disconnect them?

You have to pull the kick panels The plastic panel behind the E Brake and reach in there and unplug them..

 

[Deamers87ford]

alright thanks ill do that tomrrow

 

[multiranger]

alright thanks ill do that tomrrow

Make sure you do both sides.. I hope it helps.. Mine did the exact same thing.

But I changed all the under hood and dash wiring in mine so if you use the same dash I'm not sure...