Broken hot/cold blend

OldTrucksRock

I've been gathering parts for my recent B2200 acquisition, today was the day my pro mechanic friend and I slapped some of them on the ol' red truck.

Headlight switch didn't work
Turn signals did not cancel after turning
Key would randomly fall out of the ignition
Hot/cold blend was not connected, spin the dial and nothing happens

The headlight/turn signal combo switch and ignition barrel with lockset for both doors and gas door were replaced with new low-cost ebay parts manufactured in a faraway land.

But I had no heater switch parts, and what we found was the hot/cold blend thingy with the plastic gears was broken. Bummer.

Hope this epoxy repair holds, we'll see I guess.

Cusser

OldTrucksRock Hope this epoxy repair holds, we'll see I guess.

Depends on the composition of the plastic. Plastics such as polyethylene and polypropylene don't play nice with glues. On the other hand, about two months ago regular JB Weld did GREAT on a large broken plastic nut on my 36-year-old spa stainless steel heater manifold which would've needed cutting and repairing IF I could've found a correct-sized nut (could not locate a split-type nut, and the manifold was discontinued decades ago).

OldTrucksRock

Doh I think I meant to say the switch that controls changing from outside air to inside air.

Axel-Breaker-Earl

OldTrucksRock Doh I think I meant to say the switch that controls changing from outside air to inside air.

No......you had it right the first time. That temperature mechanism controls the hot/cold temperature (Red & Blue dial) by adjusting the heater coolant control valve that lets the engine coolant flow through the heater core. The mechanism pushes and pulls a cable wire that runs down to the heater coolant control valve and turns the lever on the valve to either open it for coolant flow, or close it for no coolant flow.......and any setting in between.

The heater coolant control valve is down by the parking brake mechanism, below the dash......and circled in red in this picture....

Here is the heater box with the heater coolant control valve being removed........for pictures! There is a short piece of rubber hose and it's hose clamp on each end of this valve.......sometimes these connections will develop a coolant leak, and make you think that the heater core is leaking.

Cusser

I was lucky once with the controls - the loop at the end of the cable had just slipped off. I can't remember if I did anything special to fix, but it hasn't happened again in 20 years....

lizardkingjr

I've used Q-Bond with much success for broken plastic pieces for my truck.

Highly recommended!

Red91EFI

Axel-Breaker-Earl

Excellent photos. In a pinch you can easily move that heater coolant control valve by hand.

Axel-Breaker-Earl

Some more pics from my 4x4 trucks heater when I was cleaning it up......

Some good pics of the heater coolant control valve......

Axel-Breaker-Earl

Red91EFI Excellent photos. In a pinch you can easily move that heater coolant control valve by hand.

Yes......that's how I discovered my broken hot/cold adjustment mechanism in the dash. I got under the dash and watched to see if the coolant valve lever moved, when I turned the adjustment knob on the dash.......and it didn't! So I pulled the dash selector mechanism out and repaired it.

Axel-Breaker-Earl

While we're on the subject of the hot/cold selector mechanism behind the dash.......there is a more stout mechanism......and it came on the earlier model trucks. My broken selector mechanism was on a 1991 model year truck......and I believe that the stouter selector came on the 1986 through 1988 model trucks, but I am not sure what year they changed the design.

Here are the two different selector mechanisms.......

The later model of the selector has a blue cable.......and I tried repairing the mechanism by melting the plastic frame back together........that was a short lived repair.

lizardkingjr

Axel-Breaker-Earl

Metal > Plastic

Red91EFI

Axel-Breaker-Earl

Yes, my 1991 dash dial/knob quit working and I'm too lazy to pull the dash off to get to it. It seems to be a common problem, I seen used ones for sale all the time on eBay. Good tip to pull one out of an earlier truck.

Cusser

Axel-Breaker-Earl I believe that the stouter selector came on the 1986 through 1988 model trucks

Either a cost-savings project or there was a technical/supply reason to change suppliers. I worked 4 decades in the soap and detergent industry, and we had a zillion (exaggerating: half a zillion) cost savings programs. These ranged from removing the cardboard liner under the wrapper of a bar of soap, having plastic bottles made thinner to save plastic, adding talc as filler to soap bars, etc. All manufacturers do similar, must feed the pockets of the folks high in management.

OldTrucksRock

Awesome photos! I'm saving all the pics for future reference.

I explained it poorly, I was having two problems at once. Neither the hot/cold selector, nor the inside/outside air selector were working. Luckily the hot/cold selector was stuck on Hot so I've been nice and warm in this first couple weeks of old truck ownership.

Since we had the vent tubes out anyway it was a good time to clean them with soapy water, 35 years of dust changes a man.