Have you tested the blower motor relay? Also, see this thread:

"http://www.superhonda.com/forum/f13/ac-blower-motor-not-working-04-lx-325133/"

 

You have to unplug the electrical connector to the blower. Then use something like aligator clips to connect 12V to the each pin.

For 12V, you can run some wires from the battery. If you have an old cell pone charger, you can cut the adapter for the phone off, then use the cigarette lighter in your car. A car battery charger will give you 12V.

 

Just wanted to say thanks to Jim Blake and others posting in this thread for providing both the diagnostics and solution for the blower having stopped on my 03 Accord. It was the resistor which tested within the ohms range but failed the jumper test. I just replaced it with part from local dealer ($70) and the a/c system now works like a charm! Thanks guys, saved me alot o money and headache.

 

Great info guys!! After testing all fuses and relays, I found this thread. I jumpered the thermistor with an alligator clip and my fan is working once again. I know I can solder in the 1 ohm across the thermistor but I would like to put in a new thermistor. Any idea what the value of this thermistor is of how I can find one? Thanks.

 

If you go to the common diy thread on top of the gen tech help forum, there is a link to the transistor repair for the 03-07 accords.

I think the reason the thermal fuse blows is because the chip inside is overheating.

I think there are part numbers on there as well.

 

Thanks. This is the first time it has messed up but it has been super hot in LA over the last week. Is a thermistor and a thermal fuse the same thing?? Can I just unsolder and replace the thermistor with this?:

5 Pcs Microtemp Thermal Fuse 142

 

The fuse sits under the circuit board right next to the microprocessor (I think that is what it is called). You have to unsolder the three leads to lift up that circuit board.

The problem is likely due to a failing microprocessor under the board. That fuse is in there to prevent heat damage (probably fire risk) when it overheats.

You can try soldering in a thermal fuse and putting some new heatsink compound in there. If you go this route, let us know if this fix lasts for a while.

 

A thermistor and a thermal fuse aren't the same thing.

A thermistor changes resistance with temperature, so it's used to measure temperature on a continuous basis.

A thermal fuse is more like a switch that opens up at a certain temperature. Unlike a temperature-switch, a thermal fuse stays open ("blown") after it goes off.

 

You could just order the thermal cutoff from Digikey and pick first class mail which will about $2.80 shipping cost.

The digikey part number P10920-ND

You'll get the part way faster than free shipping from China in the ebay link you posted. Additionally, the part from digikey is made by Panasonic. I actually ordered some before, to be able to quickly repair other friends and family member Hondas if the need arises.

The circuit board is basic, with several resistors and a capacitor. Underneath the board is the thermal cut-off and the transistor.

See the following link for more detailed pictures and how to test the transistor too.

"http://www.hondasuv.com/members/showthread.php?t=52805"

When de-soldering and re-soldering the transistor you may want to use alligator clips on the transistor legs as a heatsink to protect from damaging the transistor. See this link regarding soldering:
"http://www.kpsec.freeuk.com/components/tran.htm"

 

Thanks for the info. I noticed the heatsink was REALLY hot when using the jumper I had connected. I guess the transistor may be bad??? Seems I may just blow any fuse that I install. I found the whole assembly for $49 online so I've decided to go that route. Thanks for the help.