Topic: blower fan motor amps

[junya92toy]

Anyone want to go see how many amps their fan motor pulls on high?
Mines a 92,ex cab v6, they should all be the same Id imagine.

[brainlessfool]

so you want someone with an amp meter to go chack there fan draw to see what yours is?
is yours blowing the fuse?
"rule of thumb" fuse is 200% of load. i.e. 20amp fuse, circut load is about 10amps.
obveusly as loads get bigger that drops a bit.

[junya92toy [OP]]

TOyota doesn't use a fuse on that, Mine has melted the wires twice in 3 years

[junya92toy [OP]]

ANd I want to compare my amp draw, to other trucks

[brainlessfool]

TOyota doesn't use a fuse on that, Mine has melted the wires twice in 3 years

realy? wow I'm going to go check my truck to see if I can find a fan fuse. that just don't sound like some thing
thats not going to be fused.

[junya92toy [OP]]

It doesnt, my friends truck just melted down the fan switch too, which mine has done before.

[junya92toy [OP]]

And if there is one, its hidden.

[Zs Confederate Toy]

Drop your glove box all the way down and look behind heater control deal. There is a two fuse block for the heater and blower. Thats where it is on my 87. I wouldnt imagine that they move it too far

[unclejpl4x4]

if i had my snap-on indutive meters with me and my g-box down i could help ya  but atm i can't

[junya92toy [OP]]

Well even if it has a factory fuse,why is it getting so hot to start melting things? Without a short I should add

[brainlessfool]

what is it thats melting? the wires from the switch to the motor? the plug on the back of the switch? the motor?

[junya92toy [OP]]

First the switch melted, say a year later, the wires from the motor to the plug melted that goes to the wire harness, that was like a 5 inch run from the motor. The new motor used butt connectors, those melted.

[junya92toy [OP]]

And the wires are pretty big, I measured a 11 amp draw on high.

[brainlessfool]

over the years I've run into truble with wires to the fan. GM used a funkie connector
under the hood that was only powering the fan on high. seen many of those melted.
the fan switch on volve trucks tends to melt on the high pin of the switch if the driver runs the fan on high
all day. wires are plenty big.  butt the connectors are not up to the job and build heat.
on the GMs I used to cut out the bad spot and splice a repair. end of porblem.
on the volvoe trucks I fix (replace) the switch and tell the drivers to run the fan slower.
so if the wires plenty big then the conn. are not up to the job. fix as best ya can.

[fordh8r]

   When stuff melts it's not from Amp draw...it's caused from high resistance! High resistance will create a "back up" right where the resistive component is and start getting hot. This is why the fuse doesn't blow. While it starts out as a warm spot from the natural amperage it begins to create a bad connection when it cools....much like how and why an exhaust system will rust after a period of time.  Then the cycle begins again when it gets used again and again and it will slowly degrade until it reaches the point of failure.


   For this reason anything that runs high amperage (15 amps or more...14ga or larger) I will solder my connections for a trouble free circuit. Everything else that can't be OR isn't soldered (i.e. terminal connections, butt connectors and so on...) will get treated with a die-electric silicone grease which cuts down the heat and lubricates the connection which inhibits wear on the terminal from vibration and thermal expansion and reduces any moisture absorption when cooling...much like having an exhaust system ceramic coated. This should solve your problem or if at the very least prolong it for a considerable amount of time! This sounds like a lot more work than you may be used to for doing electrical work but I gaurantee you won't be sorry for taking that extra step when you realize how much more reliable your electrical system is! 

[junya92toy [OP]]

WEll I agree with all that but amps do cause heat as well in the wires. And I usually on connections that are exposed to moisture put grease in there, never thought about on the inside really, this is the only thing Ive had trouble with, Ive wired in lights, 12 air, stereo, winch, with no issues, just thought this was a odd issue
I have put in a inline circuit breaker this time, right before the fan motor.

[fordh8r]

WEll I agree with all that but amps do cause heat as well in the wires.

Yes, it does! Resistance just makes it worse. 

  I hope you didn't feel that I would imply that you didn't know what you were doing by my posting. I was simply stating all that to generalize for all those who read this post and in not knowing what you've covered or already done to alleviate your issue with this circuit.  Just offering my   

[junya92toy [OP]]

Ya I know, its just kind of odd the issue I'm having

[Bobby Hunter]

your talking about the small AC fan right in front of the condenser?

[Bobby Hunter]

my bad your talking about the blower motor, I guess I should learn how to read