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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: N31569 on January 07, 2017, 01:58:25 PM

Title: 102a3 defrost heat
Post by: N31569 on January 07, 2017, 01:58:25 PM
My otr heater system works fine, but I get no heat from the front window defroster.  I also have no driver heat. I have found the controls on the floor for the drivers heat , but the cables don't move at all. Are the drivers heat and defroster heat controlled by those same controls under the drivers seat?

Thanks,
Jason
Title: Re: 102a3 defrost heat
Post by: gumpy on January 07, 2017, 04:02:45 PM
I don't know about the 102, but the MC9 has a valve at the bottom of the left panel that can be turned manually to open or close flow of antifreeze to the driver's heat.

The valve is located under the outside electrical panel. I would check there on your bus and see if you can find the valve. Maybe it's stuck, or maybe the cables control something else.

Title: Re: 102a3 defrost heat
Post by: Scott & Heather on January 07, 2017, 05:59:07 PM
Jason if your push pull handles are seized, then cut the cable underneath the drivers area inside the roof of the spare tire bay. Then you can manually move the valve lever to allow coolant to go through the Heater core. I didn't get any heat until I did this and now it's hot hot hot. Jason if you need me to explain better or send photos you can text me. I'll PM you my number. This is an easy fix.


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Title: Re: 102a3 defrost heat
Post by: N31569 on January 07, 2017, 06:16:41 PM
Thanks, I'll take a look at that Monday when I have it inside, I have to pull the spare tire out anyways. Do those controls also make the defroster hot?

Thanks, Jason
Title: Re: 102a3 defrost heat
Post by: sledhead on January 08, 2017, 07:53:00 AM
b 4 u cut the cables the T handle turns counter clock wise to unlock then pull up on the red 1 and push down on the blue 1 then u turn them clock wise to lock them . they only turn 1/4 turn , lock or unlock . after you have heat at the dash and do not have the main heater fans on your dash heat will drop off if it is really cold outside . turn on the main heater fans and the heat will return to the defrost vent .
that's how it worked on my a102c3
but Scott might be right if the T handles were not used much they might be seized up try to get them moving first it you can

dave   
Title: Re: 102a3 defrost heat
Post by: buswarrior on January 08, 2017, 04:50:20 PM
restoring these valves to proper function allows you to regulate both the temperature and the fresh air through the dashboard, both at the driver's feet and at the windshield.

They are notorious for seizing.

Use your favorite penetrating spray top and bottom, let it soak in.

And check twice on the twist to lock, that's another trick that trips up someone new to the coach.

happy coaching!
buswarrior
Title: Re: 102a3 defrost heat
Post by: Scott & Heather on January 08, 2017, 07:55:06 PM
Ditto on the above, mine were done for several reasons one of which the cables were destroyed when previous owner did some air line work under there. So I had to disconnect the cable and move the lever manually to the open position which allows coolant to flow and thus heat. If you can keep the system intact you'll be able to regulate your cab area temperature much better. For me, it's "turn on overheat then turn off" if cold, repeat above steps lol. Annoying


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Title: Re: 102a3 defrost heat
Post by: N31569 on January 09, 2017, 03:37:50 PM
I got inside the spare tire compartment and found someone had disconnected the cable, and it was seized. I turned the valve on and had great heat up front. I will get the cable freed up or disconnected once the weather warms up.

Jason
Title: Re: 102a3 defrost heat
Post by: Scott & Heather on January 10, 2017, 03:51:55 AM
Awesome. You'll love it. I get enough heat to keep most of the coach warm even down in the teens


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Title: Re: 102a3 defrost heat
Post by: buswarrior on January 10, 2017, 05:29:01 AM
Some have heat, some might not...

The 102A had some design issues with the defroster, I'm not sure when in the run it was fixed?

The defroster was unable to keep the windshields clear in the cold.

You will see some earlier 102 with a lot of defroster vents cut into the windshield side of the instrument panel, some will have none.
The cut vents are the stop gap improvement.

Later models, changes were made to the dash, air delivery ducting, fan size, not sure about the heat exchanger...

In revenue service, the ice on the inside of the windshield came down below the driver's sight line... Load of passengers, wet boots, tracked melted snow puddling on the floor, all of them breathing...

Later models, this was not as much of a concern, with ice only forming up higher, and around the edges.

happy coaching!
buswarrior

Title: Re: 102a3 defrost heat
Post by: Scott & Heather on January 10, 2017, 07:30:32 AM
Interesting. I am curious when they made the design change. My 1992 C3 has vents all over. The fans are three speed and he highest speed will blow empty water bottles into the air and off the dash. The heat roasts out the driver.


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Title: Re: 102a3 defrost heat
Post by: B_K on January 10, 2017, 07:52:01 AM
Scott no worries on a "C" model! It was fixed in the "A" series and as you know it goes A,B,C,D....
;D  BK  ;D
Title: Re: 102a3 defrost heat
Post by: Danny Holder on January 11, 2017, 04:33:14 AM
I have the same problem - No heat.  Thanks guys for the information.
Title: Re: 102a3 defrost heat
Post by: Scott & Heather on January 11, 2017, 11:47:42 AM
Good to know. I've had our coach now in -9°F weather so we know we are good down to that temp at least.


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