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Electric Fan help

Old Feb 13, 2023 | 04:05 PM
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Originally Posted by BrendonM
It’s 10 amp each fan. 120W 12V

I think the relays are 40A
In that case, you'll want to use a 15 amp fuse/fan. Too big of a fuse gives a unnecessary strain to wiring and relay in case of a short, or if the fan motor starts to fail. 1,5 x constant amp draw is a good rule of thumb when choosing the fuse size.

You could also wire the relays so that when the a/c is on, only one fan works. No need to run both of them if the engine temp is in within limits, but keeps the a/c happy. But when the engine temp gets high enough, both fans are turned on.
 
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Old Feb 13, 2023 | 06:04 PM
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Originally Posted by HeikIlm
In that case, you'll want to use a 15 amp fuse/fan. Too big of a fuse gives a unnecessary strain to wiring and relay in case of a short, or if the fan motor starts to fail. 1,5 x constant amp draw is a good rule of thumb when choosing the fuse size.

You could also wire the relays so that when the a/c is on, only one fan works. No need to run both of them if the engine temp is in within limits, but keeps the a/c happy. But when the engine temp gets high enough, both fans are turned on.
is there a rating for the fans for startup draw?? That's generally pretty steep.
 
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Old Feb 13, 2023 | 06:44 PM
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Originally Posted by HeyYou
is there a rating for the fans for startup draw?? That's generally pretty steep.

sadly this is all Amazon gives me for this fan.

 
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Old Feb 13, 2023 | 06:46 PM
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Originally Posted by HeikIlm
In that case, you'll want to use a 15 amp fuse/fan. Too big of a fuse gives a unnecessary strain to wiring and relay in case of a short, or if the fan motor starts to fail. 1,5 x constant amp draw is a good rule of thumb when choosing the fuse size.

You could also wire the relays so that when the a/c is on, only one fan works. No need to run both of them if the engine temp is in within limits, but keeps the a/c happy. But when the engine temp gets high enough, both fans are turned on.

This would be my FIRST ever time wiring ANYTHING. So I’d need some help. I’ve been on YouTube and asking questions for days now preparing to do the job and I’ve learned a lot but actually doing it is going to be another story lol. I hope is goes well. I haven’t purchased the 2nd fan just yet but I will be
 
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Old Feb 14, 2023 | 01:28 PM
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Hey since I have the adjustable controller and a 180 stat what’s a good on and off temp? Ive seen like 10 over thermostat temp or even 20 over and I’ve also heard that it’s a bad idea to put it in the radiator and it’s better to tap into the cylinder heads because it’s the hottest portion of the engine and that’s what you want yoir fan to be based off of. However I have no idea how to tap into the heads. Again, I’m super beginner for fab work or wiring lol
 
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Old Feb 14, 2023 | 02:55 PM
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Well, you are wanting to cool the radiator, so, cylinder head temp really isn't that much of an issue. I usually try and put the switch in the water passage for the thermostat, on the front of the intake. Sometimes, the thermostat housing will have an NPT fitting, but, I don't think the dodges do. Think I would have the fans come on about 10 degrees over thermostat temp, off about 10 below... or whatever range switch you can set up.
 
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Old Feb 14, 2023 | 03:24 PM
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Originally Posted by HeyYou
Well, you are wanting to cool the radiator, so, cylinder head temp really isn't that much of an issue. I usually try and put the switch in the water passage for the thermostat, on the front of the intake. Sometimes, the thermostat housing will have an NPT fitting, but, I don't think the dodges do. Think I would have the fans come on about 10 degrees over thermostat temp, off about 10 below... or whatever range switch you can set up.


awesome, thank you sm! I bought the 2nd fan and it’ll be here in a few days
 
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Old Feb 15, 2023 | 01:18 PM
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Hey my truck runs below my 180 stat is that normal?? I’m getting the code P1281 for my thermostat but that’s just because my stat isn’t stock.

My live data says my temperature is 172° constant. But I read that it should be running at 180?
 
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Old Feb 15, 2023 | 01:21 PM
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Stats are about as accurate as temp gauges. The rating is just a close approximation, and some are much better at it than others. The problem you run into with that particular code is, the PCM will do it's best to get the engine up to temp, which means fuel mileage suffers..... Unless you can tune it to the new value.
 
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Old Feb 15, 2023 | 01:24 PM
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[QUOTE=HeyYou;3560810]Stats are about as accurate as temp gauges. The rating is just a close approximation, and some are much better at it than others. The problem you run into with that particular code is, the PCM will do it's best to get the engine up to temp, which means fuel mileage suffers..... Unless you can tune it to the new value.[/QUOTE


can you set temp with an SCT handheld?
 
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