dalaw

I need some help on troubleshooting wtf is wrong with my a/c blower fan on my 03 civic. It is not working. I checked the #12 fuse underhood and it is ok. Then I thought the blower motor itself is shot so I bought one off ebay. It arrived today and i plugged it in and that doesn't work either. The blower would start then stop immediately when I turn the key to "on". When I press the a/c button, the a/c compressor will not kick in either. What else is wrong?

02civic21

its your blower power transistor. its bad. you can get a new one or modify the old one. mod is way cheaper. the mod is you take the power transistor off and solder a 1kohm resistor between the open contacts. see pics answer courtesy of honda-tech member "jivi" heres the link http://www.honda-tech.com/zerothread/2041582

dalaw

ah, thanks man. I am gonna try the resistor trick tmrw. Hope its gonna work. I have tried replacing the blower motor and control switch unit and no luck. Good thing i didnt spend too much on those. Will let you know if it is really the transistor. Thanks.

02civic21

did it work?

dalaw

It works! Finally! I had been so frustrated and been driving without any air for the last month. The lowest resistor I found at Fry's was a 2.2 ohm so I welded two together in parallel to get an equivalent to 1.1 ohm and it does the trick. Can't believe its only a 50 cent fix! Props to you man!

MaxwellT

Where do I get a 1k ohm resistor? looks like radio shack has them but what W do I get.? 1/2, 1/4, 1?

gearbox

iTrader: (95)

match it to the old ones. they look like 1/2 watt to me.

CraigW

iTrader: (1)

The correct fix would be using a 114 degree C thermal cut off device. That is what was in there originally.

MaxwellT

I tried the soldering method and both heat and a/c still do not work. No fan at all. What should I try next?

CraigW

iTrader: (1)

What method would that be ??

Did you check the thermal cut-off to see if it was open ??

MaxwellT

I tried the following:

its your blower power transistor. its bad. you can get a new one or modify the old one. mod is way cheaper. the mod is you take the power transistor off and solder a 1kohm resistor between the open contacts.

I did not check the thermal cut-off. How do I do that?

CraigW

iTrader: (1)

The tco will look similar to a standard resistor, silver case 1 lead each end.

Check it with an ohm meter, should read near 0 ohms if o.k.

Not 100% sure of it's exact wiring configuration but you are putting 1k into a circuit looking for 0, & replacing a thermal fuse with a resistor.

Locate the tco & ohm it out.

CraigW

iTrader: (1)

http://www.honda-tech.com/showthread.php?t=2041582

This thread states 1 ohm.

It is a safety device to protect the transistor (like when people neglect cabin filters forever) The resistor will not provide protection.

danielw

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