OBD2A / OBD2B Harness Question

[Dc2-ProductionS]

See below for what I currently have in my setup. I need to know if I need to buy a new harness? or if this setup is going to work. From some of my research here are some things I have seen others say:

- everything will work except I wont have tach signal.
- the car will run but cluster will show nothing but engine temp
- obd2b engine harness wont clip into obd2a sub harness (mine clips right in)
- everything will work fine when going UP in OBD sequence years with dizzy. Stepping down is where problems arise.


Car: OBD2A - 97-R
ECU: OBD2A - 97-R
Sub harness from ECU to shock tower: OBD2A - 97-R
Engine Harness - OBD2B - 00/01-R
Engine Block - OBDB - 01-R (Stamped 083)
Engine Head - OBD2A - 97-R

My dizzy plug on harness side does NOT have the 2 leads on the bottom of plug. It has (1) Black/Yel. My EVAP plug is also square, not round like 97-98. Which means it is a OBD2B 00/01-R harness.....

Let me know if anyone has any details or info!! Thanks!!

[coolhandluke]

- everything will work except I wont have tach signal.
- everything will work fine when going UP in OBD sequence years with dizzy. Stepping down is where problems arise.

I believe these two are related.

the car will run but cluster will show nothing but engine temp

If I'm understanding correctly, the engine harness does not plug into the sub harness. The coolant temp (head) is what is sending the engine temp to gauge cluster. Solving the engine to sub harness may address this issue.

- obd2b engine harness wont clip into obd2a sub harness (mine clips right in)
- everything will work fine when going UP in OBD sequence years with dizzy. Stepping down is where problems arise.

Switching to a ODBIIa engine harness might be the plug and play option, but I can't speak to cost or availability.

[Dc2-ProductionS]

the car will run but cluster will show nothing but engine temp

If I'm understanding correctly, the engine harness does not plug into the sub harness. The coolant temp (head) is what is sending the engine temp to gauge cluster. Solving the engine to sub harness may address this issue.

The engine harness DOES clip in to the sub harness though.....so confusing

... this is the stuff I hate that makes me go looney tunes. LOL

[Stin1]

My friend works at hasport. I just sent him this link . He should have the answers you seek.

[Dc2-ProductionS]

My friend works at hasport. I just sent him this link . He should have the answers you seek.

This is why i love you guys!!

Thank you

[Stin1]

He's gonna need to run a wire from distributor to drivers shock tower where the extra little unused white(obd0) plug with blue wire to get tach to work
Evap purge just repin to proper plug

[Stin1]

Is the coolant temp working? I am a little confused on your post but this is what he said if it wasn’t working.

That's probably a broken wire or sensor. That sits under the distributor and always gets hot and crusty .

[Dc2-ProductionS]

He's gonna need to run a wire from distributor to drivers shock tower where the extra little unused white(obd0) plug with blue wire to get tach to work
Evap purge just repin to proper plug

This is correct. After further research and having everything in front of me when I got home from work, this made the most sense.

I was up until about 1:30am, disassembling and old harness that had the stock Blue wire in it from tower plug to dizzy. Then took apart my refreshed harness and laid in the wire. I got it loomed about 95% of the way intertwined with other wires that also fed from tower to plug. There were some bound up wires in one section taped with the light brown tape that looked like absolute hell. I tucked it away in the loom, but i did not take apart all that madness. LOL. All re done and looks good as new.

I'm glad this happened actually because as I was running this line, I found 2 plugs that their connections were being held on by just a few exposed wires. Took care of those as well. Harness looks good as new.



Thanks for the help guys, 1 step closer.

[coolhandluke]

...Thanks for the help guys, 1 step closer.

Were you able to successfully test? That wiring work sounds daunting, I hate to hear you had to rewire, but I hate wiring.

[Dc2-ProductionS]

Were you able to successfully test? That wiring work sounds daunting, I hate to hear you had to rewire, but I hate wiring.

Car is not in running order yet, so have not yet tested. However, I do have continuity through and through. All plugs and clips are connected, and all wiring colors match up.

I will report back on this thread for others once it is running to confirm this fix.