Harman PF 100 distribution blower wiring and advice?

Hello

Working on a 6 year old Harman PF100. The distribution blower is a really big! LOL
However it only works on high. I see only 2 wires connected to the 3 position toggle switch and only two wires connected to the starting capacitor. There are 3 wires just hanging there?

2 Questions

1. Any idea how these 3 wires (Red, Blue and Yellow) should be connected?
On the 1638 CFM blower the Yellow wire is the Blue Medium speed! See below:

2. Does the Harman Circuit Board turn this blower on and off in Automatic Mode?

See pics below

Click pics to enlarge:

 

You guys! LOL

For this machine, it looks like

Black=High
Yellow=Medium
Red=Low

Since the switch currently only makes the fan run on high, the problem is not only the violet and black are on the wrong post!
The fix is this:
1. shut off power to the furnace
2. Remove the black wire and move the purple wire to that post.
3. Put the black wire on the post directly behind the purple wire
4. Put the Red wire where the black wire was attached
5. Put the Blue wire on the last open post in the back

Not too hard, is it?

 

Once its wired correctly, fairly obvious that the toggle allowed the end-user to change between fan speeds with a flick of the switch.....should be fairly easy to determine what goeth where on the toggle. Subsequent newer PF120 models don't have the switch, so, the installer has to make the choice as to the speed at which the end-user will run the fan......which is being changed back at some point to a toggle switch (I am sure you see the issue with NOT having the switch)...

now, the circuit board INDIRECTLY turns the fan on. It does this by lighting the fire when the probe calls for heat, stove lights, which heats up the heat exchanger, which heats up the air in the air jacket, and the hot air rises to the limit switch in the plenum above the stove....this limit switch (Harman part #3-20-23139) in turn switches on and powers the fan. This big fan does not connect at all to the circuit board though.

 

Thanks LW
I was wondering what that limit switch does! Thanks again!

 

yup, Don, the limit switch controls when the fan comes on and off....and you can change those settings on the limit switch