One area of restoration that is often overlooked is the car’s heater. After all, most restorations are driven only in the summertime and never during very cold weather, and many of these ancient heaters don’t kick out a lot of heat at the best of times. So it’s tempting to ignore the heater or give it just enough attention so it’s not dumping Prestone on your feet.
This is a mistake, and for precisely the reason most people ignore the heater: if you drive your car only in the summertime, your car’s heater core is an additional radiator that can be used to draw heat out of your engine. That’s true for air-cooled Volkswagens and Porsches (and Chevy Corvairs) as much as it is for conventional water-cooled cars. You can drop your engine water temperature by 10 degrees or more by running the heater in the cabin.
Of course, if your car is running hot because it’s 100 degrees outside and you’re stuck in traffic, you’re likely to cook yourself until you’re medium-rare, but that’s a sacrifice most of us are willing to make.
Even if you never have to use it, a good working heater is an important engine cooling safety item. But it’s also nice to be able to kick on the heat in the cold morning on your way to a car show or just on an evening drive through the country.
You will also find that your heater works better and produces more heat if you’ve restored it with the same care you put into your radiator. Heater cores have been processing the same coolant as the radiator for the same amount of time, and if your radiator was clogged up, then your heater core is as well. And if your heater blower has become feeble over the years, a new motor or just some attention to the ground wires and controllers can restore a healthy breeze when you need it.
When you restore your heater core, take it to the radiator shop along with your radiator. They’ll be able to clean or replace the core for you. Then, when you reinstall the heater core, use all new rubber tubes and hose clamps to make sure your new installation doesn’t leak. That core is under the same pressure as the rest of your cooling system, and requires the same attention to detail.
Hook your heater blower up to a 6 or 12 volt (depending on your car) battery on your workbench and see how it blows. If it’s blowing harder than it seems to in the car, chances are you just need to improve the grounding to get it working as it should. But if it’s tired, you can often find a new replacement motor if the stock ones are no longer available. A junkyard blower motor might work, but more often than not they’ve got the same problems yours have.
Ducting from the heater in a classic car is almost always simple - just straight out through the dash or under it, and another duct up to the windshield for defrosting/defogging. If you have to choose, make sure your heater can defog the windshield - that’s a basic safety issue. Products like Rain-X and other anti-fog applications also help a lot.
As you inspect the heating and defrosting setup, make sure all the intakes (generally just underneath and in front of the windshield or at the front grille of the car) are free of leaves, pine needles, and other obstructions that get sucked down and block airflow. Also make sure any drains for condensation and rainwater are clear of dirt and debris. Some cars, notably Alfa-Romeos, will allow rainwater to flow down the air intakes right onto the electric blower motor if the drains become clogged!
With just a little work, your car’s heater will last the lifetime of your restoration. It will keep you comfortable on chilly days and in a pinch, it can save your engine from costly repairs. That’s a good investment either way.
