Dash controls won't blow cold air or switch to hot

[Rinkydink]

1999 Winnebago Brave/ P30 Chassis


Temperature control doesn't change when I try adjusting it. AC is working but can't get cold air out of the vents and when adjusted to high heat... it doesn't change either. Had a vacuum leak for the vent door actuators... Those are now working properly. I can change from Vent to floor to defrost etc... and I can't turn the fan off and adjust from low to high.


Temp control has an electrical connection to it. (see pic) I'm not sure where to start trouble shooting. I have the control out... (have a multi-meter but not sure how to test it) or should I be looking under the dash for something else?


Any input would be much appreciated!! Have always received friendly and very  helpful advice here in the past, figured this is a good place to start!


Thanks in advance,
Cheers!!


Mike

[Rickf1985]

That is a Ford control, Look at a similar year Ford pickup truck and if that doesn't look like it then look at the cars. Once you find one that matches look at the troubleshooting for that vehicle. Are you sure your vacuum supply is good and not leaking somewhere before it gets there? One of the other members is working on a similar issue, look for a thread called Vacuum accumulator.


Found it, just a couple below yours.
http://www.classicwinnebagos.com/forum/index.php?topic=15418.0

[FarPoint]

Thatââ,¬â,,¢s me (Fred) trying to figure out my controls and vacuum lines on the other thread. Sorry I canââ,¬â,,¢t offer any solutions yet, but your pics will be a big help with my heater project. Did you map out the vacuum line connections? The photos look identical to my controls in a 1997 Winnebago Warrior. BUT I had assumed that the temp control was a also hooked up to a vacuum line, as my heater bypass valve has a vacuum hose running to it. In the pics it looks like the temp. control is electric. Really gonna need a manual for this...

[Rinkydink]

I was surprised to see it was a Ford control myself... I didn't recognize it as Ford but it's stamped Ford on the back...


Fred, yes, it's an electrical connection... I have not followed it yet but will be back at it this afternoon after work. Will keep you posted. My vacuum line was also broken like the one in your pic. I fixed that and that allowed me to select where the air comes out... vent, dash, floor etc.


Really not looking forward to tearing the dash apart.... oh well!

[Oz]

I can't think of anyone who would actuslly call Dash diving "fun", but it's a very common necrssesity.  You're making progress, so that's a good thing!

[Rinkydink]

Update.


Found two more broken vacuum lines! One goes to an accuator in-line with a heating core waterline... that makes some sense and the second one is at the bottom of the heating core/ac box... not sure what it does but pretty sure it goes to the second broken line in pic below.


Best I can tell the temp control knob must electronically control the vacuum to the heater core and the door to the AC. See pics below... but think Iââ,¬â,,¢m onto it.... will get parts in the morning and see what happens!

[Rickf1985]

The top one turns the heat on and off and the bottom one appears to be the blend door. Hard to tell where it is in the picture, That would regulate the heat temperature coming out of the vents.

[Rinkydink]

And there it is!!! .... hopefully. Results tomorrow

[FarPoint]

Looks like youââ,¬â,,¢re exploring in the same area I am. Iââ,¬â,,¢ve had to take a few days away from dash diving  - hope to get back to it tomorrow. So if mine is the same, the dial temperature control In the middle is just a rheostat thatââ,¬â,,¢s telling the vacuum control beside it, what to do?

[Rinkydink]

Update.... Fred, check out this video... right around the 12 min mark, it shows our exact temperature control knob and how to check it. It's an AC video but it gets to the control knob. It is strictly electrical after all   https://www.youtube.com/watch?v=BXTZURC5iQ0  Hope that helps


For me, I did repair the other remaining vacuum lines and wha-la... I have hot air, can control the temperature and which vent it comes from.
**Lesson for others with same issue: LOOK FOR VACUUM CONNECTIONS IN ENGINE COMPARTMENT FIRST!!! I did way more work digging through the dash than necessary... although I did learn by doing it... my rig is 20 years old, the plastic vacuum lines in the engine compartment become very brittle and in my case all the breaks where in there... high heat etc... and very easy to access and very easy to repair!


I apparently do have an AC issue which led me to the fore mentioned video... but that's another topic. May see me on a new string soon!!

[FarPoint]

Thanks for the link! But in one of your pics, Rick figured you were showing your blend door. And it looks vacuum operated. So where does the heat control potentiometer morph from electrical to the vacuum actuation?

[Rickf1985]

That may have been the blend door or the recirculation door, it was hard to tell from the pic where in the system that was located. If it is the recirculation door then all it does is close off the outside air when you select max A/C.

[FarPoint]

Iââ,¬â,,¢m currently taking a short break from dash diving. In Port Hardy getting ready to take on Nakwakto Rapids. Arguably the biggest salt water rapids. Anywhere. Then maybe hit the Roaring Hole Rapids next day. Back to reality on Saturday! Gotta get that heater and AC control figured soon - wife wants to take it to Alberta. More testing needed....

[FarPoint]

My wife decided to drive herself to Calgary - family stuff - so I got busy under the dash. Heater and vent controls now working nicely. I located all the same cracked, broken, and melted vacuum lines in the same locations as Mikeââ,¬â,,¢s photos. Also had to run a new vacuum line to the vacuum accumulator thatââ,¬â,,¢s under the cowling out front.
And poof! Itââ,¬â,,¢s all working. Well, not the dash AC - yet...

[Oz]

Awesome!  (except for the dash AC, of course)

[FarPoint]

Not to worry. I am relentless. The AC will work.

[Oz]

That's the spirit!