Hi guys,

I am having some trouble finding the answer to this dilemma.

I bought a nice 1989 Civic Si, but it didn't come with an engine harness. I obviously need one to proceed with the car.

I am wondering what harnesses are the same? Obviously the DPFI harnesses are not going to work for me, but would any 89-91 Civic Si harness work as well as the CRX Si?

I remember hearing that the harnesses are a little different from 88-89 to 90-91. Can anyone shed some info? I'm fine swapping the plastic connectors if they are different.

My biggest concern is the shock tower plug pinouts. I have found a pinout for the driver's shock tower, but it doesn't specify what year it is from.

 

You could always buy an aftermarket harness from some place like MonoTech.

I'm sorry I can't help you with pinouts - I have extensive notes for a 1990 DX Auto that I converted to MPFI and 5 speed.

 

I don't think much changed between 89-91 engine wise, they should be interchangeable. The aftermarket replacement harnesses I see are all indicated for 89-91 so my assumption there is that the tower plugs are the same.

The Monotech harness looks nice and uses the tower plugs. I have their OBD0 -> OBD1 conversion harness for the ECU and its held up with no issues.

 

89, 90 and 91 engine harnesses for the D16A6 are all the same for CRX Si, Civic Si, Civic EX (MT) and 4WD wagon (MT)

the 88 harness had a different driver's side connector since it didn't have a Fast Idle Control Valve - the connector is rectangular with only 6 wires instead of round with 8 wires

this is the 88 connector:

 

My 89 Si didn't have a fast idle control valve on the D16 either, only the IACV. Thats the valve under the throttle body right?

 

89-91 FICV

 

Got it, thanks, there was one of those on my A6. I was thinking of the FITV.

 

Wow thank you! Yes! This is the community I love.

You have made my day @jlicrx