Upgrade to fan motor

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Halden
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Location: Everertt, WA
Isuzu vehicle(s): 83 Dsl LS Long Bed 4x4, 82 Dsl 2wd Short Bed 5 spd

Upgrade to fan motor

Postby Halden » Mon May 18, 2020 5:58 pm

I installed a DC motor controller on the heater fan in one of my trucks and I'm quite pleased with it.

My reasons for doing so.

1. Base model has only three speeds. The LS had 4 which is marginally better but doesn't offer the control I like.

2. Pulse width modulation uses less current and generates less heat. The heat generated is from resistance across current transistors as opposed to a resistor box in the air flow.

3. It's kinda neat.

4. Most importantly, I was bored and had nothing else to do this afternoon.

You can make a DC motor controller which uses PWM very cheaply using a 555 timer chip or buy one on Amazon for about ten bucks which I opted to do here for the sake of ease. I think I spent $15 total for everything if you count wire, connectors and mints I had laying around. My other truck I will build the circuit myself as it's quite easy with some basic electronics knowledge

I opted to mount mine on the bottom of the glove box using some vibration dampening circuit board mounts since these trucks tend to vibrate a little at idle and extended the wiring for the pot to the driver's area by the key switch.

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It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Box Dsl 4x4
82 Short Box Dsl 5 spd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard

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puttputtinpup
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Re: Upgrade to fan motor

Postby puttputtinpup » Mon May 18, 2020 7:56 pm

Nice! I vote for this to be moved to the HOW TO section, but others will need more specifics of course....which includes pictures! :)

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Halden
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Location: Everertt, WA
Isuzu vehicle(s): 83 Dsl LS Long Bed 4x4, 82 Dsl 2wd Short Bed 5 spd

Re: Upgrade to fan motor

Postby Halden » Mon May 18, 2020 7:59 pm

puttputtinpup wrote:Nice! I vote for this to be moved to the HOW TO section, but others will need more specifics of course....which includes pictures! :)



I can definitely provide more pics and some specs soon
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Box Dsl 4x4
82 Short Box Dsl 5 spd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard

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puttputtinpup
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Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: Upgrade to fan motor

Postby puttputtinpup » Wed May 20, 2020 1:28 pm

Halden, with your knowledge and ingenuity couldn't you make a variable wiper delay module using the same or similar components?

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Halden
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Location: Everertt, WA
Isuzu vehicle(s): 83 Dsl LS Long Bed 4x4, 82 Dsl 2wd Short Bed 5 spd

Re: Upgrade to fan motor

Postby Halden » Wed May 20, 2020 4:29 pm

puttputtinpup wrote:Halden, with your knowledge and ingenuity couldn't you make a variable wiper delay module using the same or similar components?


Funny you mention that. I have already made 3 circuits and am deciding which one I like better. You can find all sorts of schematics online and tweak them.

2 of them use the "555 timer". The nice thing about this little chip (that is used all over) is you can adjust the delay with a pot and also the on time with a pot to make sure the wiper motor/gear box can get on the parking contacts. I'll do a write up on whenever I get around to making my final decision and install it. Interestingly enough wiper delays are just really really really slow PWM. Applying power for a short blip to close the automatic parking circuit to make a sweep.
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Box Dsl 4x4
82 Short Box Dsl 5 spd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard

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Paul
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Location: Central Calif Coast

Re: Upgrade to fan motor

Postby Paul » Wed May 20, 2020 10:53 pm

Halden - -

Very cool idea. I have not felt the need for more fan speed control but it is a worthy project.

One thing to watch for with a PWM circuit is radio frequency interference (rfi). Fast switching generally will generate rf energy. Can be controlled by slowing down the switching speed or by using filters to catch the rfi before it can get into your radio. Problem is usually evident on weak stations on the AM band.

Also, rfi generally shows up in the AM band from the switching voltage regulator in the alternator.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

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Halden
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Joined: Thu Mar 29, 2012 5:20 pm
Location: Everertt, WA
Isuzu vehicle(s): 83 Dsl LS Long Bed 4x4, 82 Dsl 2wd Short Bed 5 spd

Re: Upgrade to fan motor

Postby Halden » Thu May 21, 2020 3:12 pm

Paul, this is something I thought about. The frequency this circuit runs at is 14.6khz when switching. Luckily you can put it in lock up so the output is always high and you can operate the fan normally thus eliminating interference. So far I've found this to be a worthwhile addition.
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Box Dsl 4x4
82 Short Box Dsl 5 spd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard