Engine wiring harness

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

J romney

Newbie
Joined
Dec 28, 2021
Messages
6
Reaction score
1
Location
Canada
Hey boys! I have a bit of a problem here, I swapped an 88 350 / 5 speed into my 94 k1500 4x4. The truck originally had a 4.3 / 5 speed. Problem is the harness that came on my 88 engine won’t work with my truck as all the plugs are different. One of my friends has a harness and computer that’s the same but it has an auto transmission. Will the ecu work in my truck? Thank you guys I’m terribly confused haha.
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,963
Reaction score
13,743
Location
The Seasonally Frozen Wastelands
the harness that came on my 88 engine won’t work with my truck as all the plugs are different.
"All" the plugs are different?

TPS, I'd believe. Either buy a conversion harness or use the '94 throttle body and gasket, with the 350 injectors. Maybe EST as well--separate on '88, built-into the computer on '94 (I think.) O2 sensor should be changed from '88 single-wire to '94 heated--probably 3-wire.

What else is different?
 

J romney

Newbie
Joined
Dec 28, 2021
Messages
6
Reaction score
1
Location
Canada
"All" the plugs are different?

TPS, I'd believe. Either buy a conversion harness or use the '94 throttle body and gasket, with the 350 injectors. Maybe EST as well--separate on '88, built-into the computer on '94 (I think.) O2 sensor should be changed from '88 single-wire to '94 heated--probably 3-wire.

What else is different?
The plugs that go into the ecu are different and the 88 ecu doesn’t plug into my truck.
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,963
Reaction score
13,743
Location
The Seasonally Frozen Wastelands
Why not use the harness and ECU that came with the truck?

I suppose you'd need a PROM or something to account for the additional displacement and cylinder count.
 

J romney

Newbie
Joined
Dec 28, 2021
Messages
6
Reaction score
1
Location
Canada
Why not use the harness and ECU that came with the truck?

I suppose you'd need a PROM or something to account for the additional displacement and cylinder count.
I should’ve mentioned my harness that was on my v6 was in brutal shape so I threw it out with the engine. I’m just wondering if an engine harness and ecu out of an automatic truck would work in a truck that has a 5 speed. Thanks schurkey
 
Top