2001 Heater fan issues

[Virago Rider]

2001 Honda Odyssey - a few weeks ago my altenator went balistic, dashboard lit up wipers went into overdrive and my heater fan went into high gear. I replaced the altenator, 6 light bulbs and a few fuses and my radio, all but my drivers side electric window is OK except the heater fan. It is stuck on high heat and I cant turn it off or turn it down or turn the tempature to cool ( on front only, rear fan / heat seems to be OK). I took out the heater relay the one next to the fan under the dashboard), no change when it is in or out, it still blows super hot air on high speed, I remoed the fan, no signs of dammage, I removed the dashborad controls, no sign of damage ( I can hear and see changes when dails are moved so the dash board seems to be still good). Are there any other items to check or should I replace the heater relay and see if that helps. There are 2 issues, the temp is always hot and the fan is always on high, both are un changed by anything I do. thanks for any suggestions, Owen

[William Wiles]

What model? LX or EX? They have different controls on the motor. EX check the blower motor high relay, blower motor relay, and a shorted power transistor.

[Virago Rider]

Hey, thanks for replying. it is an EX I believe, it has the multi level heat and speed, no just 4 speed settings. I checked the heater relay but i can't see anything. I am not sure i know what you mean by high relay and transistor. Where are they located and how do i confirm they are OK. Thanks again , Owen

[New Dad New Van]

Replace the transistor - it is an easy fix and very common.

Here is a good thread and a DIY video:

Air cond/heater fan wks only on highest setting

[Virago Rider]

I replaced the transisitor with a used one, now I have control over the temperature but the fan is till stuck in high gear and still wont turn off even when I turn the heater contoler off. The fan speed switch (multi level not just the 4 settings) seems to have no effect. Is there, and where is, the "fan high relay" or does it sound like the dash board console swithces are burnt. Thansk again for repsonding. Owen

[William Wiles]

The blower motor high relay is on the right side of the blower housing towards the top of the blower housing. Just to the right of the top of the cabin filter housing

[Virago Rider]

Thanks so much for the info, I will check into it. Owen

[klingcam]

New Dad New Van: AWESOME! I did not replace the entire transistor assembly. But I just got done replacing the thermal cutoff located inside the transistor assembly. Cost me 74 cents!! Never did this before and it took me 1/2 hour from start to finish. Now works like a dream. Considering that when the video that you provided was done years ago, and the transistor assembly was $72.00 back then, one only knows what it costs now....not to mention the labor (estimating $100) that the dealer would charge me. So, $172.00 minimum at the dealer, or 74 cents for a thermal cutoff + $3.49 for heat sink compound & 1/2 hour of my time. Fan-friggin'-tastic! Thank heaven for guys like you and the gentleman who made that video. Phenomenal forum and phenomenal participants. Thank you!

[New Dad New Van]

Your welcome - we really feel your level of gratitude.