redcamz

Hi, i just purchased a 4th gen delco cd player with svc, and according to this How to on SCV 4th gen in 3rd Gen , we can make the svc work with our 3rd gen, i have an 84 z28 305H.O. (vinG) with 5 sp, and i can't seem to locate the wire (green with black stripe) or even vss buffer by my ECM, i know in 84, we have a mechanical speedometer, but where would the vss wire that i need to tap into it be? (according to the above link)or what color is the wire? thank you.

redcamz

hi, i just did a seach and i think on the earlier 3rd gen(mine is an 84 305HO(vinG) with a 5sp, all orginal) they might not have a yellow vss buffer next to the ECM, if thats true, would there be a vss wire going into the ECM itself? and what color would it be, i have attach a pic of my ECM, any help would be appreciated it. thank you.

deadbird

The vss buffer was on the back of the speedo head for all cable drive speedometers to the best of my knowledge (take it with a grain of salt).
The buffered signal traveled a brown wire to the ECM.

redcamz

hey thanks deadbird, do you think i can just tap into the brown wire or would that cause a problem with my speedometer?

deadbird

I wouldn't think so, as the ECM and cruise share the same wire off the buffered side (brown wire) of the vss. I cant see a 3rd wire, spliced in, hurting anything just for the rahdidio.

redcamz

thanks again, when you say the buffer side, do you mean where it is plug into the ecm like in my picture? because in the link above they said tap into the green wire with black stripe. thanks

NEEDAZ

Don't just go tapping into wires. You NEED some sense that your getting the right one. He said 'with a grain of salt'. If you can't get a little firmer answer keep looking or just go out and BUY A MANUAL for your car. But something about a brown wire sound right. And as long as you get the right wire tapping into it shouldn't be a problem.

redcamz

thanks needaz, i am hoping to get more information about the wiring before i do anything, if anybody have info on an 84z wiring dialgram of the ECM, please let me know. thanks.

deadbird

I was referring to my 'knowledge' (or lack thereof sometimes) with the salt comment.

The vss is on the back of the speedo head for '84.
This is fact

Where it terminates at the ECM, I don't have a diagram of.

This is a cropped image of the cluster wiring. Notice the brown wire.. that is the buffered signal wire .

Blk/wht is ground
Pnk/blk is power from the gages fuse.

redcamz

thanks deadbird, does that brown wire goes into the ECM? and what would be the number or pin that plug into? thanks again.

NEEDAZ

Just run the wire up behind the instrument cluster.

redcamz

thanks needaz

NEEDAZ

Don't forget to post a follow-up if you get it working, or if you find that in fact your car has no VSS, here and in car audio land.