Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 13, 2025 ...

Dash Blower/ Aquahot and Engine Heat

January 05, 2017, 09:01:24 am

My problem, parked with very low temps outside and aquahot working good all heat exchangers working my LR heat exchanger and blower working good, dash vents are not blowing air but are warm, so doing research on this it seems from the info that I have found on here that the same blower is used in the dash for heat and AC, from the info that i also found it seems that when ign switch is off it switches a relay to the aquahot. Can someone tell me if there is 2 relays or just one for the dash blower? It is my understanding that there might be a relay for that circuit down on the aquahot and also one in the dash area, any help is appreciated, It is 8 degrees this morning in Colorado Springs and getting colder.  Thanks

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #1 – January 05, 2017, 09:20:58 am

Adam,  the AquaHot uses the main dash blower when the ignition is off and the thermostat is calling for heat. When the ignition is on the control of the dash blower is returned to the dash heat/AC system.

The thermostat triggers a relay on the AH to turn on the zone pump and power the heat exchanger fans for that zone.  So if your LR fans are on and heat is coming out there then that relay is OK.  There is a relay to the rear and left of the main blower box way down deep that controls whether the fan is on or off with ignition and the AH thermostat.  I did a write up on adding a switch to that so that I could turn off the dash blower when the AH is on and the LR is calling for heat.  All of the other blowers still work but run lomger. To us the LR feels just as warm and more uniform.  The dash blower tends to heat up the thermostat faster then the rest of the LR.  Running the AH without the dash blower on is OK by Rudy.

It is possible that a wire came loose from that relay or there is a bad wire to it or a bad connection at the AH.  Or the relay might be bad. 

See
Aqua Hot Dash Blower Fan Override

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #2 – January 05, 2017, 09:35:58 am

Thanks Roger, I will start at the dash, I did read your writeup on the mod that you did and will most likely do that to mine while I am in there,

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #3 – January 05, 2017, 12:36:55 pm

Dumb question but does your 99 have the dash systems using the aquahot as standard when it was built?  My 97 does not.

I know the 99's had a bigger capacity dash hest and air versus our 97 but unsure when the aquahot to the dash heat exchanger happened

Would be tempted to put a roll of bubblefoam in my dash area behind the shade for winter long term use. 

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #4 – January 05, 2017, 01:16:50 pm

Hi Adam,

If your 99 is like my 02,  if the venturi vacuum under the steps should quit working, the vacuum doors default to defrost position for the windshield. Just FYI.

Jim

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #5 – January 05, 2017, 02:53:55 pm

I found the problem, a relay was bad for the blower, I do think I might have a underlying problem as when I change it all works but it runs warm after a while use so I am thinking I probably have some drag on blower bearings which will be so much fun to change if that is the issue,

My 99 has dual blowers, driver side and passenger side, not sure if aquahot uses both blowers or just one, also not sure how that woeks, there must be a partion in heater and ac box with 2 blowers, would need to dig some,

Jim last time I drove coach was 2  months ago and at that time my shutters were working, defrost and floor and dash, Thanks for the heads up though.

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #6 – January 05, 2017, 02:59:43 pm

The '99 U320 blower is a PITA  I was able to see where it was when I changed the a/c expansion valve on mine.
Here are some pics.

dash air expansion valve

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #7 – January 05, 2017, 03:04:24 pm

Good to know; Thanks

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #8 – January 05, 2017, 05:08:16 pm

Changed the blowers out on my 01 and had to pull apart the whole front of the coach to get to it.

Quote Selected

Re: Dash Blower/ Aquahot and Engine Heat

Reply #9 – January 05, 2017, 05:58:25 pm

If you have to change it out, better done when it is nice out but before it dies altogether.

Quote Selected