73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Projects Posts (NOT VEHICLES) => Topic started by: Dr_Snooz on February 12, 2025, 12:19:51 am
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It was a night of miracles here. I'm trying to get this Griffin radiator installed in my truck. They sent this fan switch along with it.
(https://1drv.ms/i/c/5667f57ff74aa46c/IQR61qKbQXoaTpqu2WqXjhODAZ-isZDPl4QDL_jtRjYv-5Q?width=1024)
The obvious question is what's the best, easiest place to put it? I asked AI, but it doesn't know anything, so I'm posting this up for posterity.
On my truck, with a 350 small block and stock heads, there is this plug in the passenger side head, between the #6 and #8 spark plugs.
(https://1drv.ms/i/c/5667f57ff74aa46c/IQSWb_TzKhsYRoqpm8A3paikAZI-EkWqMv4steW4EZbvDvo?width=1024)
It's the obvious place to put a fan switch, but it's not that easy. The plug won't accept anything in your tool box. It's square.
(https://1drv.ms/i/c/5667f57ff74aa46c/IQThjJcLt2LXT6HwwsbUXmJmAexuKXSZIrkgvpH5zm35LDo?width=1024)
5/16" square to be exact. So no, your socket extensions won't work. You'll have to run to Big Orange and scare up a length of 5/16" square bar, which is hard to find. You can grind down a 3/8" extension until it fits, but that's tedious and the heat will probably anneal your extension so it fails. Keep a tub of water nearby to quench it as you grind. By some miracle (like I said, it was a night of miracles), I had a scrap of 5/16 square bar in my deceased father's tool chest. It's been there unused for maybe 30 years until tonight.
I thought the new switch would thread in easily, but again, no. It's too small. I figured I'd have to buy a brass adapter from Summit and wait another week to get it. Except I couldn't find an adapter. Nor could I find the thread sizes I'd need. In desperation, I went to my scrap plumbing box and grabbed random bits to compare the threads against. Turns out I already had what I needed (miracle #2). The threads on the switch are 1/4" NPT. The threads in the block are 3/8" NPT. I had a galvanized bushing adapter that worked perfectly.
Here's everything you need. Even thread sealant.
(https://1drv.ms/i/c/5667f57ff74aa46c/IQRgHLIkXLYfR5nc91beg1wOARrDXDsmfO41n8vGl15YuFY?width=1024)
And the completed install.
(https://1drv.ms/i/c/5667f57ff74aa46c/IQSp0CEprwzER6LV-tWGkJEkAWhzvRCAUQnUfhSx--_ag6U?width=1024)
It took me all evening to figure that out. Hope it helps someone else.
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That's where I put mine on my last electric fan add-on car (87 Z-28)....I used a JET-brand switch, and it was a piece of cake.
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I can always find the hard way to do things. I'm good like that.
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Funny, Mine came with a temp probe and a rheostat temp range adjuster.