Warm dash A/C

Covers engines and transmissions
chuckster
Posts: 286
Joined: Thu Aug 27, 2020 4:53 pm

Re: Warm dash A/C

Post by chuckster »

wolfe10 wrote: Tue May 04, 2021 1:41 pm An option if you want the dash A/C to work is to install a ball valve up front on the inlet to the heater core. Close is cool.
Hi Brett!

Pardon my mechanical ignorance in the automotive HVAC world but what how would the ball valve be opened/closed? Maybe shoot me a link that would show how this works? Would this negate a need for control head?

Thanks,
Chuck & Mitzi
'01 Safari Zanzibar 3646 (side entry)
Cat 3126B / Allison MD3060
Magnum M-Series "Blue Max" chassis
2016 Jeep Grand Cherokee Overland toad
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Warm dash A/C

Post by stuplich@ymail.com »

chuckster wrote: Wed May 05, 2021 10:21 am Hi Brett!
Pardon my mechanical ignorance in the automotive HVAC world but what how would the ball valve be opened/closed? Maybe shoot me a link that would show how this works? Would this negate a need for control head?
Thanks,
chuckster
See how to operate a ball valve here: https://www.youtube.com/watch?v=-d8aA8_SDE4
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
wolfe10
Posts: 222
Joined: Sun Oct 27, 2019 4:12 pm

Re: Warm dash A/C

Post by wolfe10 »

The ball valve would be inserted in the heater hose to allow you to completely close off flow of hot water from the engine to the heater core.

Not in HVAC control at all-- just a 100% mechanical way to keep heat from the heater core.

Brett
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
chuckster
Posts: 286
Joined: Thu Aug 27, 2020 4:53 pm

Re: Warm dash A/C

Post by chuckster »

wolfe10 wrote: Wed May 05, 2021 1:55 pm The ball valve would be inserted in the heater hose to allow you to completely close off flow of hot water from the engine to the heater core.

Not in HVAC control at all-- just a 100% mechanical way to keep heat from the heater core.

Brett
Would the valve location be a royal pain to get to to get heat working again in the winter??? Is it in the front of the coach? Near the 3126? I'm clueless! :D
Chuck & Mitzi
'01 Safari Zanzibar 3646 (side entry)
Cat 3126B / Allison MD3060
Magnum M-Series "Blue Max" chassis
2016 Jeep Grand Cherokee Overland toad
wolfe10
Posts: 222
Joined: Sun Oct 27, 2019 4:12 pm

Re: Warm dash A/C

Post by wolfe10 »

chuckster wrote: Wed May 05, 2021 3:19 pm
wolfe10 wrote: Wed May 05, 2021 1:55 pm The ball valve would be inserted in the heater hose to allow you to completely close off flow of hot water from the engine to the heater core.

Not in HVAC control at all-- just a 100% mechanical way to keep heat from the heater core.

Brett
Would the valve location be a royal pain to get to to get heat working again in the winter??? Is it in the front of the coach? Near the 3126? I'm clueless! :D
I would locate it up front where it is easy to access, but it can be anywhere in that line. If you have motor-aid water heat, yes it will have to be up front so coolant can still circulate to the water heater.
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
Knollibe
Posts: 64
Joined: Mon Oct 28, 2019 10:38 am
Location: Garden Grove calif

Re: Warm dash A/C

Post by Knollibe »

I got mine here. It has extra Button for rear defrost. And you may have to de pin one of the harness plugs and re use your old one

https://www.ebay.com/itm/131919282331
Dwayne
1996 safari Sahara since 2010
Chev Colorado zr2 toad, electric pedego bikes.
3rd motorhome.
Knollibe
Posts: 64
Joined: Mon Oct 28, 2019 10:38 am
Location: Garden Grove calif

Re: Warm dash A/C

Post by Knollibe »

Heater valve should be in front on heater hose

https://www.ebay.com/itm/303480680314
Omega 31-60030 pull to close.
Dwayne
1996 safari Sahara since 2010
Chev Colorado zr2 toad, electric pedego bikes.
3rd motorhome.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Warm dash A/C

Post by TDJohn »

When the suggestion came up to install a ball valve, Chuck asked where the easiest place to locate it. Some responded up front. This is not the case, as this is a later model Zanzibar and they did not have a front access panel, like many of the older coaches did. So IF there is easy access to the engine from the top, I would suggest to locate the ball valve near the engine.

Regarding other options, it appears to be that the diagnoses is the control head is not providing the proper resistance to the electrically operated control valve. If a control head can't be procured, a couple of options come to mind. Either installing a rheostat switch to control the electrically operated valve, or replacing the valve with a mechanical valve, something similar to this one: https://www.finditparts.com/products/59 ... s-31-60030
and installing a choke cable to operate the valve.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
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