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Question About Denso Air/Heater Control Switch For My RV

by Gary Bohn
(San Jose, CA USA)

I have a class A 1985 33ft automate royale motorhome. The control switch for the air/heater on the dash has broken. I have found that a Denso #146430-3450 will work and I have found one and it is being shipped now. I need to know how to hook up the four vacume lines going to it, I can not find it anywhere. Maybe you can help me. I sent in another question that you helped me alot. Thanks Gary

ANSWER Hi Gary, well I am glad I was able to help you out with your other question. I am afraid I may not be as much help on this one. Let me go back in my memory to my mechanic days. First, I hope you have not already removed the old switch. If you are very lucky the new Denso switch will have the same vacuum port configuration as your old one. If it does, it is just a matter of switching the vacuum lines off of the old one to the new one.

If you have already removed the old switch and as well as the vacuum lines then it is going to be a matter of trial and error to get the lines on the right ports. Also if you are lucky the vacuum ports on the new switch will be labeled as to what they do. But, this will do you no good unless you know exactly where all of your existing vacuum lines go. Tracing where these vacuum lines go can be a pain in an RV.


Also do not be surprised if once you get everything hooked up properly that you may still have problems with your AC/Heater. You may find that you have some vacuum actuators that have gone bad.

Based on the way you worded your question, it sounds like you are planning to replace the switch yourself. In some cases it may be better to have an experienced mechanic do this repair. The money you spend on having this repair done by a mechanic may prevent a lot of heartache trying to do this repair yourself.

This is the best I can do without actually being there and seeing the configuration of the old and new switches. Maybe one of our visitors have done this repair recently and can give you some suggestions, if so they can click on the add a comment link located near the bottom of this page.

I wish you the best of luck and Happy RVing.

RVing Al

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by: Richard

Acmeairparts.com
Ac & heater parts for motorhomes.
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by: rv tech

This may sound strange, but I have actually found information that you may be able to use at the local library. It may not be on the motorhome itself but if you know the chassis it is on and fine the right truck model it could have been, back track to looking for the trucks manual, which will usually show a diagram of this system and what attaches to what.This may help your dealer to, if they have younger techs without a lot of experience on older motorhomes. Good luck.

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