Who has actually done the obd-1 vss conversion/adaptation and HOW?

[Accordtheory]

Title says it all..I tried the 6k ohm pullup resistor between 12v and the vss wire, still throws the code. My car also seems to have an inconsistent speed limiter over about 80 mph. wtf, I am assuming it is vss related. 95 ls swap. (95 ls ecu anyway)
Anyone who knows something I don't, please clue me in on this..

p.s. i don't have an oscilliscope..

[thegreatdane]

Did you use the cruise control vss signal to feed the ecu? That's the one you need.
Based on what guynabo89 posted i mocked up this tiny guide (I havent had a chance to test it out myself yet though):

[Accordtheory]

I just did it right at the ecu jumper. Isn't the wire going to the cruise control the same as the one going to the ecu? The signals both come fom the same place, right? How can you cut the connection to the guages when the signal itself comes from the guage cluster??

[thegreatdane]

No, they're not the same. The one going to the ecu is amplified in some way that makes it useless for obd 1 and the one going to the cruise control is not amplified. You take the wire on the gauges that runs to the ecu and you remove it from the gauge plug (or cut it) and splice that on the wire going to the cruise control. Plus you add the resistor.
Better?

[Accordtheory]

Thanks. I'll have to break out my service manual to find out what wire is the one for the cruise control, and then I'll run it to the ecu..hopefully that will solve this..

[EricW]

The speed pulser should be a yellow/red wire and the speed sensor should be yellow wire.

The yellow wire goes to the ECU and should be B18 on the stock ECU harness.


Please correct me if I'm wrong since I will be doing the OBD1 conversion some time this summer.

[SQ is the SQUAD]

great work guys

[Accordtheory]

A2 to C1 on the guage cluster..seems to work..thanks again

[EricW]

I thought i would post this to help others identify the dash cluster wires.



This image is on page 25-54 of the online manual and 25-73 of the 1987 printed manual.