Electric Fan swap causing problems

So I recently acquired a 2000 Tahoe the previous owner was in the middle of swapping out the motor driven radiator fan for dual electronic fans from a newer model silverado. I was helping in the swap as the vehicle became mine midway thorough the conversion. At first you would need to plug the fans in under the hood after starting the car and unplug after turning it off. We finally got around to wiring them up to a toggle switch however when doing so we wired one connection to an ignition fuse under the steering wheel. After wiring everything up we took it on a test drive and after a few minutes on the road the gauge cluster cut off it was receiving no power but the truck was still running. After we brought it back we unplugged the wire from the fuse, which was still intact. But now it will not start and we can not figure out why when you turn the key it does not even try to turn over there is no signal getting to the engine telling it to start has anyone had a problem like this doesnt have to be the same cause as mine but if you have had electrical problems that sounded like this I would love to hear how you went about figuring out what the problem was or how it got fixed please it is very urgent Im about to start work and need a vehicle we spent forever getting the transmission back in working order only for this to happen and it has us scratching our heads we dont even know where to start

You are going to need to take a meter and test out lots of wiring and fuses, to see where you do and do not have power. Most likely you guys damaged a ground strap when installing the eFans, but the link between the alternator and the battery is known to rot over time as well; a good bump against a rotten wire will take it out of service.

Alternately you'll want to get it to a mechanic so he/she can do the tracing -- and it won't be cheap.

did you connect power for the fans directly to said wiring/fuse or did you run it through a relay to run the fans. have you checked the fuses yet or just assumed it was still good as the truck was still running? electric fans draw a decent amount of power so using an ignition source to trigger a relay is a good option for constant on fans. trying to draw the entire power feed through that source is a bad idea as you are potentially drawing high amount of amps through a system not designed to do it. first thing to do is just check all fuses first. well maybe not all but instead of figuring out which ones are part of that ignition source and checking fuses is easy just check them all.

The Fans draw serious power. You have to run relays under the hood, to power the fans. And the hot wire that is being fed to the contacts of those relays has to come directly from the battery, or alternator (preferably with a big fuse in-line). Learnings from having done this conversion on a truck: 1) You need a high output alternator, 2) You likely may need a smaller pulley on your high output alternator, 3) You can't start both fans on high at once, the voltage will dip badly. Low speed first, delay, then high speed.

drakon543 said:

did you connect power for the fans directly to said wiring/fuse or did you run it through a relay to run the fans. have you checked the fuses yet or just assumed it was still good as the truck was still running? electric fans draw a decent amount of power so using an ignition source to trigger a relay is a good option for constant on fans. trying to draw the entire power feed through that source is a bad idea as you are potentially drawing high amount of amps through a system not designed to do it. first thing to do is just check all fuses first. well maybe not all but instead of figuring out which ones are part of that ignition source and checking fuses is easy just check them all.

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Agree check all fuses prob blew one.All meaning big fuse's and small ones under hood and dash board.Let us know from their.

Good luck with this, like others said the fans can draw 100 amps so I’m hoping you used relays and wired them with their own fuses. The best way to accomplish this job is to use a factory harness with its own relay pack and have the pin on the ECM turned on so the computer can control the fans or use an aftermarket harness which can use the ECM or a thermostat. I’m guessing you either blew a large fuse or -hopefully not- burned a wire.

Must not of been to urgent or he fixed it no reply in a month.

Please provide a photo of said "ignition fuse under the steering wheel" or where you had it connected because there isn't one, at least not under the steering wheel.

corvette744 said:

Must not of been to urgent or he fixed it no reply in a month.

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It was a drive-by posting!

I absolutely hate the newbs that join just because they have a problem, then come on here and post once or twice and then disappear with no update on whether it got resolved. Waste of time.