V-8 conversion wiring question

[oldfox]

Hi, I have a 91 fox that I am going to change over to a V-8. For a donor car I have a 89. I have been reading the post and threads on this but I still have a question. From what I have seen it looks like I will need to use the 89 wiring harness. But will I need to change all of the harness?
Like pull the dash and switch all the wires? Or does the harness have just sections that will need changed? And if i do need to change everything will it all plug in ok to the 91 switches?
any help would be appreciated Lee

[Sonic03snake]

I have a 91 efi harness I would trade for your 89 if interested. Should be a direct plug in then.

[INSANELY CRAZY]

need 89 to switch over to mass air on 87-88 v8

90 stands alone in all wiring

91-93 is compatable

ive done this many times and did alot of research,so no the 89 harness will not work with 91 wiring. plugs are different on driver's side under hood.

[Freakingstang]

need 89 to switch over to mass air on 87-88 v8

90 stands alone in all wiring

91-93 is compatable

ive done this many times and did alot of research,so no the 89 harness will not work with 91 wiring. plugs are different on driver's side under hood.

this is correct, unless you want to cut and splice.....Done a few myself, don't recommend cutting and splicing unless you solder all the connections. Wire nuts, butt connectors, spade terminals, etc don't belong in this application.