Need help with wiring

[Mkuhn138]

I'm putting my computer and harness back in my 87 K5 after dropping the new engine in (TBI to Carb swap). I'm weeding through all of the sensors and misc wiring I no longer need and cutting/capping them back at the computer. It's been so long since I pulled the harness that I cant remember how it went together, and to top it off I'm working off a marginal quality wiring diagram. There are a few sensors I'm not sure on and can't find on the diagram.

Pic 1 - grey sensor with a single green wire running straight back to the computer

pic 2 - sensor with black/white and light blue wires running straight back to the computer, and a purple wire running back to the fuse block. I think this is the TCC solenoid, but my diagram indicates different colored wires

pic 3 - is the fuel pump prime connecter that comes off of the relay - I'm not sure what/where this connects to.

Any help is much appreciated.

 

[Alpha1victor]

I will look this up in my amazing book of wiring mayham as soon as my crazy littlegirl goes to sleep and stops poking me in the eyes.

 

[nvrenuf]

86 trucks are carbureted and his 87 has tbi, the harnesses are very different.

 

[Mkuhn138]

Ok. Was able to figure out #3 on my own - google searching lead me to realize the prime connector is only used in testing the prime function of the fuel pump/relay when connecting a 12V power source to it.

I now have two additional questions.

4 - Purple wire coming off of fuse block - I'm assuming this is the ignition switch to the starter solenoid. Only things throwing me off is it has an inline fuse right before the connector. Also, can't remember if the ignition switch wire connected to the old starter via terminal or spade connector. I have a mini starter on the new engine and it uses a spade connector.

5. What is the pink wire coming off of the fuse block? I can't find a connector on anything that matches this one?

 

[dyeager535]

Pink wire on *some* of the trucks was the fuel tank sending unit guage wire.

But as I recall on the later trucks they went to another color. But it would have gone through the fuse panel either way.

I'd offer to take a peak at my wiring diagram, but being a '91 manual, I *think* the fuse panel is different, at least on the engine side, since they went to the different connectors.

I can't view the pics, what is the on the other end of the pink wire?

 

[Mkuhn138]

It's a gray connector with 3" or so white wire coming out of it with a small plastic connector on the end of it. I read on third gen that it could be the power source for the old coil and the white wire is an output for a temporary or testing tach. Does this sound right? If so can I use this wire for my HEI distributor?

 

[British Slave]

That green wire goes to the temp sensor on the driver side cylinder head.

 

[British Slave]

4 - Purple wire coming off of fuse block - I'm assuming this is the ignition switch to the starter solenoid. Only things throwing me off is it has an inline fuse right before the connector. Also, can't remember if the ignition switch wire connected to the old starter via terminal or spade connector. I have a mini starter on the new engine and it uses a spade connector.

The diagram I have shows that going from the starter solenoid to the engine control module.

 

[dyeager535]

It's a gray connector with 3" or so white wire coming out of it with a small plastic connector on the end of it. I read on third gen that it could be the power source for the old coil and the white wire is an output for a temporary or testing tach. Does this sound right? If so can I use this wire for my HEI distributor?

Yes, it is one of the coil wires. White is tach output.

There are two wires/plugs for the coil, not sure which one of the two you'd want.

 

[Russell]

Yes, it is one of the coil wires. White is tach output.

There are two wires/plugs for the coil, not sure which one of the two you'd want.

The grey connector is indeed the power / tach wiring for the old TBI ignition coil. Use the pink wire to feed your HEI.

The purple wire is your starter wire. That little "fuse" is actually just a strain relief. It hooks directly up to the S terminal on your starter (you'll need to put a spade connector on it to match your mini-starter.

Not sure what the three wire white connector is for. Definitely emissions related though

Green wire from the junction block is your coolant temperature sensor wire.

 

[Mkuhn138]

Thank you very much guys this helps out a lot. The green wire and connector is actually coming straight from the ECM. I have the temp sensor wire identified already coming out of the fuse block, but this one is something different ...

 

[British Slave]

Thank you very much guys this helps out a lot. The green wire and connector is actually coming straight from the ECM. I have the temp sensor wire identified already coming out of the fuse block, but this one is something different ...

There is a green wire coming from the ECM to the "B" injector wire.
There is a dark green wire from the ECM to the AC Comp
The coolant temp wires are yellow and black
The engine temp sensor is a green wire and that grey terminal plugs on sideways to stay as far as possible from the manifold..
That according to the CK Truck Wiring Diagram Section 3 Page 1