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Wiring and ECU Pinning for Electric Fans

6:09
27:23
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At 6:09 in

FACTORY Electric Fan Conversion! Best Mod For 99-04 Silverado/Sierra/Yukon/Tahoe (Free Horsepower!)

What happens here

Install the new factory-style relay box and wiring harness. The relay box should snap directly onto a designated slot in the vehicle's fuse box area. Next, connect the provided ECU pins to the harness. The presenter uses non-insulated crimp connectors and a pair of crimpers, applying them to the wires that will be inserted into the ECU. The green wire typically goes to pin 42 on the blue ECU connector, and the blue wire to pin 33 on the green ECU connector. Use a pick tool, such as a screwdriver or dedicated terminal tool, to carefully open the pin slots on the ECU connectors and insert the newly crimped wires. It is necessary to lightly 'spit' on the pins or use a lubricating agent to help them slide into the tight holes. After inserting, ensure the pins are securely locked in place. The harness also includes power and ground connections; the power tab should be bolted directly to a main power source, and the ground wire to a reliable chassis ground point, preferably a cleaned-up spot on the cylinder head for optimal conductivity.

Goal: Integrate the new electric fan harness into the vehicle's electrical system and ECU.

Tools and materials

  • Brake Cleaner — Cleaning ground surface
  • Crimp Connectors — Attaching pins to wires
  • Crimpers — Crimping connectors to wires
  • Drill DeWalt — Enlarging ground bolt hole
  • ECU Pins — Connecting fan control wires to the ECU
  • Factory-style Wiring Harness — Main electrical component for fans
  • Lubricant — Aiding pin insertion into tight slots
  • Pick Tool — Opening ECU pin slots
  • Vise — Holding the bolt for drilling
  • Wire — Connecting to ECU pins

What they say

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Let's see what's going on here. Look at this. That peg right there Mhm. slides right onto that, and this harness would go underneath all of this stuff. Aha. Yeah. Oh, this is factory AF right here. I am so Oh, man. Check this out. Ready? So satisfying. This just works so well. It's almost like it's supposed to be there. Cuz it is. Okay, well, that part's covered. So, I bolted that power tab right to there, which is probably where it's supposed to go based on how this wire was like kind of bent already, like its natural inclination was already to go there. So, either went there or there. I don't know. That seemed to be easier, so I used it. Now, we're going to have to pull these connectors off of the ECU again with the 7-mil socket. I freaking hate these things. They're just like annoying, but whatever. Here we go. Diving in. Or This is really simple. Like we're pretty much almost done. We just have to do that, put the actual fans in, and plug them in cuz this is already This harness here already has it. Factory stuff is fun. So, I'm going to use these non-insulated uh connectors here cuz they're cleaner. Uh but actually, I'm out of heat shrink, so I was going to electrical tape them. And when you use these when you use crimpers, you want to put the bulbous part on the seam of the connector, so it will like curl in like like this. See how that's like curled in like that. Yeah. Dora the Explorer. Yeah, I see. Oh my god. Yep, that's what we're doing here. I'm just going to put it in here just like that. And I'll do it down here, too. Now, that's a That's a good connection right there. It looks nice. You still got those pins nice and safe? Yep. Cool. Inside joke. If you weren't here at the beginning of the video, you don't understand. Which is also like my lame attempt at that joke because if you are watching this part of the video, I would say there's a very high probability that you watched the beginning of the video, too, cuz it comes before this. Yes. I am a special kind of stupid. A goober. I'm a goober. I'm a goofy goober, yeah. See, I kind of squished it, and then I squished it again the sideways to, you know, make it rounder. If I had heat shrink, this would look so money right now. That meme, the goofy meme. I'll do it again. Yeah, freaking We'll do it again. From what I read, the green wire goes to the blue connector, and the blue wire goes to the green connector. I'm just looking at this online the same way anybody else would. I Google things.…

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