Dash AC blower fan - (Only Off or High works)...plus water in the horn solenoid

[Tom Patton]

My dash AC blower fan now operates only on Hi speed.

I replaced the switch (lo, Med, HI) and it still only operates on HI setting.

What in the world regulates the speed if not the switch?

I'm confused.

Also (on a different note), I replaced my horn solenoid a month ago (appeared to be getting water accumulating at the solenoid valve).  Is there a water drain valve at the front of the RV?  How do I keep the water out?  Water separator filter recently replaced, and very little water accumulation at the rear drain valves.

[David T. Richelderfer]

I am/was thinking about placing extra air line after the air solenoid, enough to make a large loop in the electrical bay so that water coming down the line from above where the horns are located could have a low-point to collect, instead of running into the solenoid.

Other than something like that or a dryer/collector of some sort we can take Gerald's advice - after/during a rain storm or periodically honk the horn to blow the air line out.

[Edward Buker]

Seems like this would work well on the horn and you can get a visual if it is accumulating water which might be better then a loop. The water source would be the horn side, so what would normally be the air inlet from a compressor would be on the outlet end in this application so the instructions would be off. Nice drain valve that is convenient.

https://www.amazon.com/Neiko-Tools-Water-Separator-Spray/dp/B002GQ3SUA/ref=pd_sim_sbs_469_1?ie=UTF8&dpID=51ngQG5EheL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&psc=1&refRID=RQED9KDVXWRMDH89VSXR

Regarding the fan speed issue there is a unit usually mounted low under the front, mine is near the steering box with a resister coil that drops voltage to reduce the fan speed. Sounds like this unit is defective. It is mounted there to shed heat outside of the coach.

Later Ed

[Gerald Farris]

Tom,
The fan speed switch does not change the fan speed. It just directs the current to different resistor loops in the fan speed resistor or to the high speed relay. If all lower speeds are out you probable have a problem with the fan speed resistor as Ed mentioned. It is located on the firewall, usually in the left lower portion.

Gerald

[Larry Dedrick]

Tom:
         If you are getting only one speed from your fan check to see if you can select other settings, such as your floor outlets, or combo floor and dash outlets. if these are not responding and all you get is air out of your defroster outlets, you may have a failed vacuum pump. When the vacuum pump fails the Dash A/C system defaults to defrost and I believe you will only get one fan speed.
          This is what occurred on ours. Prior to getting the vacuum pump replaced, I would tap on it and it would start working until the next engine shutdown. After vacuum pump was replaced all operated normal.
          Hope this will help or at least you can eliminate the vacuum pump as the source.

                Good Luck;       Larry D