Like it says, how many amps does the fan draw? Just picked up an adjustable thermostat that can handle 16 amps, wondering if I can use it without a relay? Larry
I'm thinking you're talking about a fan switch not a thermostat.
The relay supplies the heavy voltage/amperage to run the fan and the fan switch just provides a ground for the relay. The relay also uses inputs from the A/C to turn the fan on. Do you plan to include these inputs too?
Like it says, how many amps does the fan draw? Just picked up an adjustable thermostat that can handle 16 amps, wondering if I can use it without a relay? Larry
I bought an adjustable thermostat that can handle 16 amps and am wondering if it will handle the fan current directly or if it will have to use a relay also. This is what I got, cost me all of $7.00 delivered:
You could wire your thermostatic switch into the fan relay, similar to the stock fan switch. Set it up to ground the green/white wire when activated, and you're set.
There is no AC, and I see the fan fuse is 20 amps, since it is normal to fuse a circuit at 200% it looks like the fan draws about 10 amps, guess I need to just measure it. Larry
ACDelco Rad Fan Part # 15-8498 spec is 150 watts / 14 volt = 10.72 Amps max. (in Watt Story)
Just wire new switch/whatever between ground and grn/wht wire on fan relay.
Note> Fan E Fuse IS NOT Rad Fan power. Read fierosound picture.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Because my thermostat is good for 16 amps I think I will just skip the whole relay thing and just let the thermostat switch it on directly. Simple is good. Larry
Figured I would just put it up against the input coolant line and wrap some insulation around it, put the dial on the dash some place so it can be changed from inside the car, should be dead easy I think. Larry
I'm thinking that all the cooling system components between the engine output and engine input all contribute to the cooling process. I'd be inclined to locate the sensor on the input line to the engine so that if the coolant returning from the rad is too hot the fan comes on. A location not immediately adjacent to the engine would likely be better so that engine or engine compartment heat don't affect the sensor. For all it matters, maybe the rad output line wouldn't be much different.
When I measured a rad fan, through an amp meter, it peaked about 80 amps for a split sec to start it spinning and running it was about 18 amps. I tried a couple of fans and got the same result. All stock fans. results may differ but this is what I showed, even used two different amp meters.
Originally posted by sardonyx247: When I measured a rad fan, through an amp meter, it peaked about 80 amps for a split sec to start it spinning and running it was about 18 amps. I tried a couple of fans and got the same result. All stock fans. results may differ but this is what I showed, even used two different amp meters.
Factory Fan motors is likely so... Did you check volts at motor? Volts does matter... Bad power/grounds will make motor to draw more amps, a common problem in old cars. See my Cave, Electric Motors
What kind of meter(s)? Inductive or shunt. Hooking up a shunt can cause volt drop and motor draw more amps to make up the watts. I would test but my meter has 10a max shunt.
# of Watts I post came from ACdelco web site for new ones.
I got an amp meter(gauge) and all the current went through the gauge, I used a battery charger to provide power. This was all hooked up just for testing. one test I used the gauge meter and another I used a Craftsman engine analizer with an amp meter built in. and I tested a few different fans all had the same results. (All stock fans)
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