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How much current does the cooling fan (singele speed) draw? by trotterlg
Started on: 09-08-2013 12:53 AM
Replies: 18 (1580 views)
Last post by: sardonyx247 on 09-11-2013 05:25 PM
trotterlg
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Report this Post09-08-2013 12:53 AM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
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
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Report this Post09-08-2013 09:54 AM Click Here to See the Profile for fierosoundClick Here to visit fierosound's HomePageClick Here to Email fierosoundSend a Private Message to fierosoundEdit/Delete MessageReply w/QuoteDirect Link to This Post
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?

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phonedawgz
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Report this Post09-08-2013 11:04 AM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by trotterlg:

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


Well over 16A.
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trotterlg
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Report this Post09-08-2013 11:54 AM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
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:

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Report this Post09-08-2013 01:29 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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trotterlg
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Report this Post09-08-2013 02:54 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
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
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trotterlg
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Report this Post09-08-2013 07:04 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Now I know for sure what it draws, I measured it. Starting it draws 11 amps and running it draws 6.9 amps. This makes it about a .12 hp motor. Larry
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theogre
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Report this Post09-08-2013 07:50 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.

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trotterlg
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Report this Post09-08-2013 07:59 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
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
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David Hambleton
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Report this Post09-08-2013 08:36 PM Click Here to See the Profile for David HambletonClick Here to Email David HambletonSend a Private Message to David HambletonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Where are you putting the temperature probe?
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trotterlg
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Report this Post09-08-2013 09:20 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
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
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Report this Post09-08-2013 09:25 PM Click Here to See the Profile for David HambletonClick Here to Email David HambletonSend a Private Message to David HambletonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Engine input or rad input?
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trotterlg
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Report this Post09-08-2013 10:30 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I don't really know if it should be on the input to the radiator or on the output of it. I would guess the radiator input? Larry
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David Hambleton
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Report this Post09-08-2013 10:42 PM Click Here to See the Profile for David HambletonClick Here to Email David HambletonSend a Private Message to David HambletonEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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trotterlg
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Report this Post09-08-2013 10:49 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I will probably do what I usually do and attach it where it will fit and is easy to get to. Larry
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sardonyx247
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Report this Post09-10-2013 02:38 AM Click Here to See the Profile for sardonyx247Click Here to visit sardonyx247's HomePageClick Here to Email sardonyx247Send a Private Message to sardonyx247Edit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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Report this Post09-10-2013 11:01 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
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.
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trotterlg
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Report this Post09-10-2013 11:59 AM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Inductive amp meter does not work on DC. Larry
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sardonyx247
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Report this Post09-11-2013 05:25 PM Click Here to See the Profile for sardonyx247Click Here to visit sardonyx247's HomePageClick Here to Email sardonyx247Send a Private Message to sardonyx247Edit/Delete MessageReply w/QuoteDirect Link to This Post
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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