CELEBRATING 20 YEARS!

Here is the scoop, I recently rebuilt my engine and like many others took out the computer harness, BUT, here is the difference, From what I gather alot of us are just pulling the sensors, and not cutting out the harness at the computer like I did. So for those of us that have cut the harness, and now have no Cruise Control fear not!!! The only thing that we need to fix is..

Find your buffer box, it is a small green box located behind the stereo(drivers side) there is a total of 7 wires coming out of it. Three are together coming out of the bottom (RED, GREEN, BLACK) these wires run to the VSS on the back of the speedo, GREEN is 12V, BLACK is Ground, and RED is the SIGNAL to the BUFFER.

Next you will find two harnesses on the top off the buffer box, one SINGLE YELLOW wire, this sends the signal to the Cruise Control Module, also there is a 3 wire harness, this is where the BIG PROBLEM lies, PINK/W BLACK STRIPE wire is your 12V to power the VSS, BLACK/W WHITE STRIPE this is the GROUND, THIS WIRE USED TO GROUND TO THE COMPUTER HARNESS, THAT IS WHY YOUR CRUISE WONT WORK!!! CUT THIS WIRE AND GROUND IT WITH YOUR STEREO HARNESS. NOW YOUR CRUISE SHOULD WORK. Also has a brown wire, this can be ignored, it is the VSS signal to the computer.

IF this doesnt fix your CRUISE after you have removed the computer harness let me know, I have been through this entire system and know it pretty well now, I am positive that I can diagnos your system, just try to be specific with your problem, and what you have done.



Chris

Good info, thank you

you guys should of seen the happy dance I did when it worked, felt as good as the first time the engine ran.

Chris

ill have to try that and get mine working.

why did you have to CUT your computer harness out? i pulled the whole thing out, without cutting any wires.

i actually ran my sub power wire through the hole it left and used a piece of hard plastic to seal the rest of the hole up.

I'll print this out and try it out on the Malibu. Right now I've got the computer and complete harness laying on the floorboard just so the cruise will work.

200kSS, that should work for you if not let me know and I will try to help you out.

i had to cut all the wires that are in the dash harness that went into the engine compartment. The computer harness did unplug, I just thought I would rip it all out, but now starting to regret that.

Chris

thank you. will try this after i put all the stuff back on...took it off cause it diddn't work. thank's again u are a good man

this should also become a question on the FAQ section, very good info here.

I just added the original info to the SS FAQ Electrical section. Thanks for the reminder.

Not to start anything but why not use the 78-80 style cruise that doesn't have the ECM?

It's probably a matter of using what you have - and if I am reading that right, it is as simple as manually grounding one wire that the ECM used to ground

How about this question for the experts, that I'm NOT! I put a TPI with a 7730 computer in my car. I needed the 4-pulse VSS. Any idea what is a good cruise control to use in the Monte body with the TPI computer and harness?

Not for sure, but I would think that if you could get your vaccumn solenoid from the stock monte cruise over to a fender, and a detent cable from the vaccumn solenoid to the TPI unit, you should be able to keep the stock cruise from the monte.

HTH

I will know more when I finally get an LT1 for the beast. But I think I will try to keep the Stock cruise system. Everything else under my hood is already Camero.

Chris

before i start getting out blade and hacking up a perfectly good harness, i should ask if i can run this setup, the re grounded wire, on a ss with the ecm still in use. im pretty sure that everything else on the setup is perfect , vac lines, motor connector, everything, but i just want to know if this has the same effect on an ecm car. thanks guys
Max

thanks 85SSMan i appreciate this great info. i think i had already read this somewhere here on the forums but regardless where i read it. i appreciate you posting this great info. thanks juan...

If you plan on going with a 4L60E or T56 where there is no mechanical speedo drive, its easy using a cruise control drive from an Impala or Caprice and the LT1s PCM. I think its a half dozen wires all together. I'll be trying this later this year with my car, which did not have factory cruise.

It is completely feasible if running the mechanical speedometer to use the stock system as there is no hookup to the stock ECM, but that cruise assembly with the vacuum actuator is PLAIN UGLY!!!!!!

Thanks I will try it.

I agree!

Pretty much same question.
Mine is a 1985 body with an 87 motor and ecm. Cruise doesn't work have vacuum but no power at the connector on the side of the diaphragm?
Mike

Not only is my ECM gone, I also replaced the stock speedo with a mechanical Autometer speedo.
In 2000 I purchased a VSS form jegsthatrun with hopes to reinstall my cruise and never got around to it. Turns out I got the wrong VSS so 9 years later I called JTR and they are sending me the correct parts for my VSS.

My question, how do I wire it up? JTR told me that one wires goes to ground and the other goes to the VSS input. Where is the VSS input? The Haynes manual that I have is absolutly no help. So I managed to borrow the 1988 Monte Carlo electrical services manual (yes, I scanned every page into PDF format ).

So if you are like me and have aftermarket gauges and no ECM, you will need to ground the wire from the buffer as mentioned in previous posts and in the FAQ.
In addition, the VSS from JTR has two wires; one goes to ground, I will go into more detail on the VSS wire.

Now this is my theory, please correct me if I am wrong:

From what I have learned, there are three wires in our cars that go from the buffer(green box) to the back of the speedo (where the factory VSS is located). You have a red positive, black negitive and green is the VSS signal, correct? I believe the green wire is what you need to splice the JTR speed sensor into.

I will not know if this actually works until I receive my parts from JTR and install my heads. Maybe this weekend I will know if my theory is right or wrong.

Ok, my cruse works! Yippee!

I got the VSS from JTR last weekend and installed it. It did not work at first, i hooked it up to the green wire coming from the stock VSS behind the speedo going to the buffer. The buffer is not required for this VSS to work, so I pulled the yellow wire from the buffer, cut the end off and wired it to the VSS, and PRESTO!