I'm doing an LS swap and have almost everything wired in already, but I was going over my C207 and noticed a ground wire. Do I need to ground this wire to the chassis or engine or do something else with it entirely? It's a 1986 2.8L and the ground is connection "M" (Black/White)

A second separate question - I have an unused (Pink/Black) wire in the engine bay. I assume it's from the AC but I don't remember now. It seems to be relatively thick, maybe 12 gauge. Would I be able to split this power wire (I assume it's 12v keyed power like the rest of the (Pink/Black) but I'll confirm) among 2 or 3 different fan relays? Not as the main source of power but as the 12v keyed source.

I look forward to your advice and responses.

 

if you have a distribution block you can take the pink wire for the coil and power everything ignition hot with it. thats a pretty thick wire. the LS harness will have a ground for inside but you dont need to put it on c207, let it ground to the body inside the car. Dont forget the 2 that go on the back of the heads.

 

The C207 ground is for the cluster. Ground it literally anywhere

The 12ga pink wire in the engine bay goes directly from the column ignition switch to the coil. LS swaps typically don't use it at all

 

C207 pin M in my '89 2.8L is speed buffer ground coming from the buffer box. I think it was a shared ground with the vehicle anti-theft system too. It was essential to ground that wire somewhere.

But do you have either of these systems in your '86? They might have repurposed that pin over the years, I don't know.

 

Which wire or wires would you recommend to run 12v keyed power to the fan relays?

 

I don't think so. I'll probably just ground it just in case. Thanks for all the responses.

 

Service diagrams do show the buffer box ground for both 86 and 88. From experience, most of the cluster will be inop without that ground

Use the old alt/fan relay fuse wire. It's a small 18ga designed to kick a relay coil. Main power should come from the battery on a 10-12ga cable
Simplified diagrams in here
https://www.thirdgen.org/forums/ltx-...-diagrams.html