Recent Posts

1

Electrical / Re: TCC lockup pin location

« Last post by frotosride on Today at 07:54:48 pm »

I have kept the brake switch without vacuum hooked up. I'm letting the Terminator handle (-) control for the relay and the brake switch (+) for tcc lockup. Also plan to use the 4th gear grounding circuit as input for possible future tuning configs.  Thanks again

2

Electrical / Re: TCC lockup pin location

« Last post by frotosride on Today at 07:48:37 pm »

Thank you, I swear I looked through all of the diagrams listed for '87 but couldn't find this diagram. The ones listed/pinned say 1987 but are printed for 1988 and have more pins. I almost just put it back together where ever I had a free spot. But I stopped so I can do body mounts. I did find #420 on the other chassis diagrams but the bulkhead connectors didn't look right.

Did you pull this sketch from the ones pined above?

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Electrical / Re: TCC lockup pin location

« Last post by bd on June 10, 2026, 12:53:04 pm »

The purple wire (Ckt 420) supplies I+ to the TCC solenoid from the brake switch.  It routes through the firewall bulkhead connector as shown.  Is this the wire you are questioning?

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Electrical / TCC lockup pin location

« Last post by frotosride on June 10, 2026, 10:18:25 am »

Looking for where the torque converter lockup (+) purple wire pins in at the firewall. Honestly can't remember if it is a separate plug/connection or if it was originally on the main bulkhead for the fuse panel. It's been so long that I can't remember where I de-pinned it from.

1987 V10 Silverado 700r4

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Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Captkaos on June 10, 2026, 08:49:45 am »

When you say the left tank comes on, do you mean the fuel pump or?

This part is confusing to me, what exactly do you mean by this:

But I'm bypassing the solenoid valve for the fuel selection Only , it's still being used for the fuel gauge readings.

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Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Ocho on June 09, 2026, 09:53:51 pm »

Left tank pump i should've said

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Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Ocho on June 09, 2026, 09:51:23 pm »

Let me get those details for your. Thanks. The problem I'm having is a soon as I turn the key to on,  the left tank comes on regardless of dash switch position.

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Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Captkaos on June 09, 2026, 03:51:42 pm »

I am going to have questions first for a better understanding. 
What issue are you chasing?
Was your truck spec'd for above 8500 GVW and has a Hot fuel module?

Those appear to be tan/white wires coming out of that terminal and it should not an issue since the are connected/spliced anyway.  What are the numbers on that terminal for Brown, Dk Grn, tan/white, X, pink, yellow and lt grn?
120 tan/wht = fuel pump relay
both in-tank pumps and the fuel selector valve
920 tan = left tank pump & selector valve,
921 gray = right tank pump & selector valve
150 blk = ground

The dash gauge switches between tanks by the selector valve. 
30 pink = gauge
930 pink/white = left tank sender
931 pink/black = right tank sender

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Electrical / 87 R10 dual tank pump issue and hot fuel module

« Last post by Ocho on June 08, 2026, 10:16:13 am »

I'm doing an LS swap on my truck with carburetor. I'm using the factory dual tank setup with the selector switch and fuel pump relay as original. But I'm bypassing the solenoid valve for the fuel selection Only , it's still being used for the fuel gauge readings. Here's my issue, and I'll include a picture. On my bulkhead connector there's a terminal that comes out with two tan wires. One goes to the fuel take selector switch on the dash and the other wire goes straight to the left fuel pump. This terminal activates with key on. Therefore, energizing the left fuel pump and eliminating the ability to use the tank selector switch on the dash. Question is, should there be two wires coming out of this terminal? Because I can't find any wiring diagrams that show two wires coming out. My other concern is perhaps this feeds to the hot fuel moduleal and it is defective, therefore allowing voltage to pass through the module and straight to the left tank. Been chasing this for a few days so any help is very appreciated

10

Members Rides / Re: 81 K10 Build

« Last post by Mike81K10 on June 03, 2026, 08:17:23 pm »

I painted the cross on the tailgate. Some outline by stencil and the rest by hand and air brush. Wish I had more in-depth air brushing skills to do intense air brushing.

Look forward to the other projects on the forum. Keep it rolling! You are all the best!