'73 heat selector switch
<hr style="color: rgb(209, 209, 225); background-color: rgb(209, 209, 225);" size="1"> I've had my '73 Ranger Camper special for going on three weeks. Runs well, so I've been fixing the little things: instrument lights, instruments, tailgate latch, etc.

The heat selector lever was non-op. The fan was running full-time, so I unplugged it. I found part of the switch (a plastic nub with a push-on internal star washer type of thing.)
The weather's been in the 70s and 80s but that's about to change. I've checked LMC and NPD but neither lists a heat selector switch for my '73. Is this part year specific? Looks like factory air, if it makes a difference.

Thanks,

JW

 

Factory installed Integral A/C. Integral means the A/C is combined with the heater. The A/C controls are within the heater control panel.

Dealer installed A/C (two types): The A/C controls are separate from the heater control panel.

1) Deluxe dealer installed A/C. The A/C is combined with the heater. The HUGE dash bezel covers up the entire right side of the dash including the glove box.

The A/C switches are mounted in this bezel, a separate glove box is bolted to the bottom of the dash.

2) Economy dealer installed A/C: Not combined with the heater. The two A/C switches are mounted in a panel that also contains two registers. The panel mounts into the dash, to the left of the extant glovebox.

Factory A/C: Mounted to the A/C Heater Control Panel is this: D5TZ19B888A .. A/C Vacuum Control Selector Valve Assy (Motorcraft YH285) / Obsolete

This valve has ports for all the vacuum hoses to attach to. The small "kicker switch" that turns the A/C on...is part of and mounts to the top of this valve w/a C clip. Fits: 1973/79 F100/350 & 1978/79 Bronco.

When you slide the levers on the control panel, this valve opens one damper door and closes another. The doors themselves have vacuum motors mounted to them.

If you aren't getting any heat, there is more than just the valve and/or the damper door vacuum motor(s) that could be causing the problem.

With factory A/C there is also a vacuum controlled heater water valve: D4AZ18495A (Motorcraft YG136) / Available from Ford.

This valve is spliced into the heater hose adjacent to the back side of the carburetor and is a notorious POS!

This little charmer is in-famous for getting stuck in the closed, or open, or in the partially open position.

Another cause of no heat may be the rubber vacuum hoses. They can become age cracked where they attach to the selector valve, damper door motors, the heater water valve. Or they can get kinked.

 

Bill---

I deeply appreciate your response.

I don't own a factory manual for the '73 yet and I don't recall my '68 using vacuum switches so I assume that manual would be useless to me. After the initial surprise, it would have taken me hours of searching and cross-referencing to get that info and frankly I doubt I would have found it at all.

I'll be removing the gauge cluster this week to put in a new lens so I'll get a good look at what I have. It's not the Deluxe air, so it must be the standard issue factory air. If this is indeed what hides behind my dash:5TZ19B888A .. A/C Vacuum Control Selector Valve Assy (Motorcraft YH285) and it's obsolete as you say, is locating a functioning '73 assembly in the JY my only option?

Thanks,

JW

 

If the A/C controls are in the same panel as the heater controls, the truck has factory installed Integral A/C.

inre to the selector valve used with factory A/C, I found 5 NOS (New Old Stock), two at Ford dealers, 3 at obsolete parts vendors.

 

I think I located one. I'll call the company on Mon. That part number was a big help. It means I don't have to pull the dash apart once more to remove the part and again in a couple of weeks. It's not so much I'm lazy or that pressed for time but the more I pull stuff apart the greater the chances of breaking more stuff!

Bill, you are one well connected and/ or one frighteningly organized dude.

Thanks again.

JW