Wire harness with unknown pink end

[Horsman]

Started installing my new engine harness from M&H and found something strange. On the end that goes to the driver side of the 402 that attaches to the temperature sender I found in the new harness a pink and blue wire, the pink wire is thick, covered in heat insulation with a female plug and the blue wire has an end that looks like it would attach to an oil sending unit. My original harness did not have the blue or pink ends.

Does anyone have any idea what this thick pink wire is for?

[Livrat]

Yes,the blue one is for the non gauge dash, it attached to the oil pressure sender, the larger pink one is for the fast idle solenoid on the carb

[Horsman]

Originally Posted by Livrat

Yes,the blue one is for the non gauge dash, it attached to the oil pressure sender, the larger pink one is for the fast idle solenoid on the carb

Thanks for the info!

I guess I have the wrong harness, I have a manual gauge. Is the fast idle solenoid on all 1972 C20 A/C equipped trucks, I do not rememeber seeing one on mine nor the wire connection on the harness?

[Livrat]

I think M&H puts the blue oil sender wire in all engine harnesses, you just wont use it, Just like they put two different connectors on the temp gauge wire,
Yes I do believe the fast idle solenoid was for all AC trucks.

[Horsman]

Originally Posted by Livrat

I think M&H puts the blue oil sender wire in all engine harnesses, you just wont use it, Just like they put two different connectors on the temp gauge wire,
Yes I do believe the fast idle solenoid was for all AC trucks.

Yea, I was thinking the same. Maybe someone could post some pics of the fast idle solenoid?

[Livrat]

here you go, the two on the bottom right are the solenoids

[Horsman]

Originally Posted by Livrat

here you go, the two on the bottom right are the solenoids

Would those be correct for my truck?
Again it is a 72 C20 with a 402. I did not see one on the truck before disassembly.

[Livrat]

Jeff, I can not say for sure what trucks did or did not have the fast idle solenoids, these both came off of Quadrajet 4bbls but I can not remember the exact applications, maybe someone could chime in and confirm??

[ryanmctee]

Jeff, I'm in the exact boat as you. Installed the same M & H harness, and have the same two wires that apparently won't get used. My carburetor is a Edelbrock 600 cfm and I don't have the fast idle solenoid. Is that how you ended up, not using either wire? Just wondering.... Also, I'm having trouble getting power to my fuseblock, and am thinking I need to remove all the packing grease M & H puts on both sides of the jucntion block. Did you have this problem as well. Thanks - Ryan

[Classic Heartbeat]

The grease is electrical grease it doesn't inhibit the electricity. It is applied to keep corosion from getting started in the fuse panel. All of the big block harnesses came with the pink fast idle solenoid wire and the blue temprature sending unit wire. You just don't use them if your truck doesn't have them. You can either clip the wires back and tuck them into their harness or just leave them alone. It shouldn't hurt anything. WES

[SS Tim]

Originally Posted by ryanmctee

Jeff, I'm in the exact boat as you. Installed the same M & H harness, and have the same two wires that apparently won't get used. My carburetor is a Edelbrock 600 cfm and I don't have the fast idle solenoid. Is that how you ended up, not using either wire? Just wondering.... Also, I'm having trouble getting power to my fuseblock, and am thinking I need to remove all the packing grease M & H puts on both sides of the jucntion block. Did you have this problem as well. Thanks - Ryan

I believe a maufacturer should stand behind their product so...
"...please contact our technical support line at (562) 926-9562. Please do not e-mail us with technical questions or problems, you will not receive a reply. Call !!!".

And on the grease issue

"What is that Brownish/Black grease on my new harness?

Some of our Engine & Forward Lamp Harnesses utilize a special di-electric grease as original. The grease is smothered inside the bulkhead connector that mounts to the firewall. Do not remove this grease; it is a corrosion inhibitor. Do not allow the grease to come in contact with your clothing, as it will stain."

[ryanmctee]

SS Tim, I certainly didn't mean to ruffle any feathers. I am VERY impressed with all aspects of the M & H harnesses, and have already recommended them to some friends. I Just thought I would ask a question from a fellow board member before calling the tech support.

[SS Tim]

No problem, just trying to help out a bit. Sometimes info can be hard to find and with me its often inverse to need. Besides when was the last time you saw a vendor tell you to not email, but instead call them?

[Horsman]

Originally Posted by ryanmctee

Jeff, I'm in the exact boat as you. Installed the same M & H harness, and have the same two wires that apparently won't get used. My carburetor is a Edelbrock 600 cfm and I don't have the fast idle solenoid. Is that how you ended up, not using either wire? Just wondering.... Also, I'm having trouble getting power to my fuseblock, and am thinking I need to remove all the packing grease M & H puts on both sides of the jucntion block. Did you have this problem as well. Thanks - Ryan

The pink wire I just taped back in the harness unused. I removed the oil sending unit plug, put some heatshrink on it and taped it up in the harness. I have a big block non A/C 72 Suburban with California emissions that uses the pink wire plug, it apparently is for an anti-diesel valve??

Do not remove the grease, it is there to help keep out corrosion. Make sure the junction is plugged in all the way and get your test light out and start probing for voltage.

Hope this helps. -Jeff