Hi, I just installed a 4th gen delco radio with scv, I need to find the vss wire by the ECM in order to make the scv to work, did a seach and could not find the wiring for my year, 84z28 305(vinG) 5speed. any help would be appreciated, thank you.

 

Your speedo is mechanical. However, i think there is a vss box or something at the speedo you can tap into. Hopefully someone with more knowledge on mech speedos will chime in...

 

you can tap into the wire at the ecm just get a wiring diagram of the ecm to find out what wire it is

 

Near your ECM is a clear connector call the I/P (instrument panel) connector. There should be three branches in the harness, two go to the ECM and the other is the IP connector.

Unplug that connector.

If you look at the end of the connector you can see that one row is shorter (has fewer pins) than the other. On the shorter row: the second wire from one end (it should be the only dark brown wire in that set) is the speed signal. You should be able to tap off of that.
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Oh, yeah, almost forgot: Plug the connector back in

 

And if that works let us know, here and in your other post in the audio forum.

 

Hey Jza, thanks for that info, are you talking about this group of wires that are not directly plug into the ECM, but attach to the side of it? there is one brown wire (see pic), i will give it a try this weekend and let you know how that turn out. thanks so very much.

 

sorry, here's the picture
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sorry, I can't seem to attach the picture with this new fomat.

 

sorry, here is the picture again

 

and here is another view

 

Yeah, that's the connector, but the brown wire looks like it's the one on the end?

Dunno, but for an '84 it should be brown, and all the diagrams I checked show brown for that circuit. I don't think they switched to gray until '90 or '91.

 

Hey Jza, thanks, I will tap into the shorter end(bottom end) with the clear plastic side of brown wire and let you know how that work. thank you very much.