MC8 Driver heating configuration

windtrader · December 27, 2017, 08:56:02 PM

Today, I looked behind the two panels in the frontside stairwell wall. It looks like this area has been modified and there was nothing in the manual to indicate what specifically goes in this area. The following two images show the heat radiator and fan housing. In the fan housing there are two squirrel fans. There is some wood fabrication and the metal surround has been cut along the top.

Seems like it's the driver heating system but the baffle, radiator, fans, etc. functions don't seem obvious.

https://www.dropbox.com/s/v1wp941zt9fid6z/Inside%20front%20panel2.jpg?dl=0
https://www.dropbox.com/s/7vjvb579krvxnvx/Inside%20front%20panel.jpg?dl=0

First one without metal surround installed. Second image, note the cutout on top for the hoses. Inside the black box on the left are two fans.

Dave5Cs · December 28, 2017, 08:04:11 AM

Don , Images?

robertglines1 · December 28, 2017, 10:09:09 AM

heater/defroster combined. Sounds like some one wanted a different fan . The motors might be on a separate reostadt ?switch. should be very loud on high. I had a mci-1978.

windtrader · December 28, 2017, 11:09:22 AM

updated OP to show links to images, not sure why it was not displaying them. thanks

lostagain · December 28, 2017, 11:46:29 AM

The box on the left with the squirrel cages looks stock. On the right is where the air conditioning unit used to be. Someone installed an auxiliary heater there to give more heat up front for the copilot. I have been thinking about doing just that.

JC

bevans6 · December 28, 2017, 12:15:30 PM

I recall the wiring for the motors was complicated. I remember tracing it out and deciding the motors were in series for low speed, and in parallel for high speed. Long time ago though. I like the idea of an aux heater core to replace the AC coil I took out.

Brian

Templar52 · December 28, 2017, 02:32:02 PM

This heater is probabely for the entry stairs. We had that heater on ours busses back in the 80'
Alain

chessie4905 · December 29, 2017, 04:23:51 AM

My 4905 defroster motors are wired the same way. Wired in series on low and parrallel on high. More reliable than using a resistor block.

Oonrahnjay · December 29, 2017, 06:42:45 AM

Quote from: chessie4905 on December 29, 2017, 04:23:51 AMMy 4905 defroster motors are wired the same way. Wired in series on low and parrallel on high. More reliable than using a resistor block.

And more efficient. A resistor block drops motor speed by creating heat which is just electrical energy that you can't even kiss goodbye.