Don't know about the 642, but in general, the thermostat must open before coolant flows to the radiator. In order to provide coolant flow (and heat) to the heater, there's a bypass connection coming from the water pump to the heater core, and a return back to the block somewhere. This lets hot water circulate thru the heater core when the t'stat is closed. I've not yet figured out where this connection is on my 751, but will have to solve that puzzle at some point. Where'd you buy your heater? ---Bob
You did connect it to your by-pass hose? this will allow coolant/water to flow even when the engine is cold. This is so that the water is moving when the engine is running, even when cold. If you have connected it this way, your heater core may be blocked? failing that, i see no reason why it shouldn't be working.
After some staring at it and spittin' on the floor I figuered it out. The by-pass port on the water pump is actually the return line or suction if you will. I thought it was a supply. With an inline hose heater installed backwards, the coolant cannot not flow due to an internal check valve. I turned my inline hose heater around and all my troubles went away. Thanks for the feedback.
Glad it worked. So where did you buy the heater? I'm not looking forward to routing a couple of heater hoses up through the tilt-back cage on my 751. ---Bob
I am curious also where you got your heater? Also, what kind of cab do you have or will have. I have a 753 that might be able to use this same setup for winter plowing.
I saw a 753 at auction that had flexible clear plastic/rubber covering the ROPS (the sort you can use for protecting outdoor areas from the weather) on the outside of the cab and a removable piece that sat over the front of the cab. This way, in summer you can simply remove the cover and work in relative comfort.
Sorry for the long delays in responding, I'm not on my PC everyday. The heater I have was actually used under the passenger seat on an older Bronco. It was not factory but an aftermarket unit my father inlaw put in. But, just today I was at a Fleet & Farm type store and their was a brand new unit almost identical to mine. $109.00 complete w/ three speed switch. I'm trying to remember the brand name of the heater---no luck. I'm sure I will be through that town again soon and I will take another look. The biggest issue I had installing the heater was re-vamping my parking brake. On my 642B the parking brake is right between your legs on the floor. It's a fairly large peddle that you would push forward with your foot to engage. I wanted to mount the heater right above the peddle. I ended up removing the peddle and fabricating a 10" long handle to actuate the brake. It works well and looks good to. The heater cooks me out in 10 to 20 deg. weather but I will soon find out if it's enough, it gets a wee bit colder than that up here in northern MN.