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I went to use the heater for the first time on my '47 Clipper limo today but it doesn't blow hot or even warm air. I looked under the hood and didn't see a heater shut off valve on the water pump like my '40s GM products have.

And I'm not sure how to turn the rear under seat heater on either. I thought it was the knob in the middle of the seat by the floor. But I turned it stop to stop both ways with no effect.

When I pull the heater button out on the dash, I do hear the fan kick on, in the front only though.

I find nothing in the shop manual that references the heater.

Can anyone here fill me in on some common issues with the heater that I might check?

Shutoff valve may be on the top of cylinder head between carb and firewall. If no valve, believe both heater cores are in series and possibly one of the hoses going under car has dropped down and kinked. Not sure about the switch for turning on underseat heater as there may be more than one type & location--or is it controlled from the rear seat in a limo? If the fuse is good, any chance something has fallen into the grill blocking the fan from turning..

Check the coolant level!

Check the hoses and the Ranco valve as well. Perhaps it leaked and was plugged or bypassed at some point in the past.

Good point about the hoses and bypass but IIRC the Ranco valves didn't happen till 48. I think yours is just two?? heater cores in series with maybe a shutoff valve on the head. Being a limo, it could have had something other than standard items so certainly couldn't rule one out.

HH56's description of the heater arrangement is correct; also, he provides good trouble shooting suggestions.

If I recall correctly on my '47 Custom Sedan, the underseat unit is controlled by the "Heater" switch and the heater-defroster unit on the firewall is controlled by the "Defroster" switch. Your Packard may be different. I have found that is easy enough to remove the front seat cushion to check the top of the underseat unit.

(o[]o)

Coolant level is topped off. But I suspect that the thermostat is stuck open or missing as the temp never increases past the 1/4 way point. Good in the summer, bad in the winter.

I'll trace the heater hoses and see where that leads me and I'll pull the seat cushions to see what's under there.

I was hoping that there was a valve that I was overlooking.

Thanks guys.

The heater core on the firewall ,they get plugged up with whatever from the inside of the pipes and then they dont work ,soif its an original part its likley jammed up ..is the line going into the heater core hot its usally from the waterpump or near it ? touch it .how about the line comming out .I replaced the heater core on my 52 ,it was available .theres also the oil cloth ducts that take air into and through and away from the heater core ,the one going away dould be warm if theres air flowing through it these bad bowy can get full of trash and not let air through them ,if you can use them at all theyve probably been replaced as they'd be falling apart

while working on my 39 120 sedan, I pulled the rubber hoses off the heater so that I could clean it up. The hoses appeared to be made from peat moss - they were so brittle that they literally fell apart in my hand. Needless to say the piping was pretty clogged up. The of/off valve on my car is a turn valve on the block. Not very easy to get to, but pretty simple in operation.

For Packards without an under seat heater, the correct heater hose plumbing should be from the valve at the rear of the cylinder head to the heater and the return hose to a fitting on the water pump. The idea behind this arrangement is to get the warmest water to the heater and then return it to the pump so it can be circulated through the radiator for cooling.

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