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Joe, RV Technician
Category: RV
Satisfied Customers: 796
Experience:  Associates Degree in Automotive Technology , 18+ years as RV and Commercial Bus Technician
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I have a 99 allegro 29ft p30 workhorse dash blower only

Customer Question

Hello I have a 99 allegro 29ft p30 workhorse dash blower only works on low ...any clues where to start looking I'm thinking it may have a high speed relay ? I did look at the dash switch looks fine
Submitted: 3 months ago.
Category: RV
Expert:  Joe replied 3 months ago.

Hello, my name is Joe

Typically, there is a blower speed resistor that enables the different fan speeds. Often the resistor will fail.

Typically the blower resistors are located in the front outside of the AC/heater plenum box.

See the image for a typical blower resistor location.


Customer: replied 3 months ago.
Thanks....I changed the resister .....the old one looked ok burn or rust on the springs
Customer: replied 3 months ago.
In the manual it says there is a high speed blower relay just not sure of location
Expert:  Joe replied 3 months ago.

Thanks for the update,

Some a/c systems use a relay to provide the blower with a high speed circuit.

If yours has a relay, it will certainly be mounted somewhere outside of the Workhorse / chassis fuse box.

Does your coach happen to have a relay screwed to the outside of the heater plenum like the one in the picture?

Can you see a name or brand on the a/c plenum? Evans tempcon , or Denso are popular a/c system suppliers to the motorhome coach builders.


Expert:  Joe replied 3 months ago.

Just checking in to see if you need any clarification on something which I stated above.
Please remember to rate my service, so I can receive credit for my help.

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