On many vehicles it’s the most difficult component to get to, and such is the case with the Hombre as well. Among those folks doing an EV conversion and replacing the heater core with an electric element, it’s a frequently-heard expression that most auto manufacurers start with a heater core hanging in space, and construct the car around it. In most cars the heater core is buried so deep in the dash, it’s a major endeavor to get to it, with multiple assemblies and sections of under-dash infrastructure requiring removal.

Some people go the easier route, forgoing the disassembly of the dash and installing an electric liquid heater in the engine bay, to warm the water in the heater core (in the place of the former gas engine). This approach doesn’t work nearly as well, but the simpler installation is tempting. As for me, I’ll be doing it the hard way, replacing the heater core with a PTC ceramic heater element, like the kind you find in inexpensive space heaters. Unlike simple glowing-wire resistive heaters, ceramic heaters generate lots of heat without the concentrated high temperature of an incandescent wire. This makes them less likely to start fires. Doing this installation will require not only replacing the heater core, but custom-fabricating its replacement. The effort will be worth it however, as unlike the heated water approach (and indeed unlike the heater in a gasoline-powered car), the electric heater will provide nearly instantaneous heat, seconds after it’s turned on.

The way this is usually done is to start with the absolute minimal ceramic space heater, which can be had for between $15 and $20 depending on where and when you look. I bought one at Target a couple weeks ago for $17. These heaters are sold under a multitude of brand names, with slight variations in the shape and color of the case, but they’re all a simple, cheap assembly involving a ceramic element in front of a fan in a cube-shaped plastic box. No oscillation or digital temparature control, no fancy curved shapes. I’ve seen these simple cube heaters sold for $35-40, but if you’re paying any more than $20 you’re being ripped off. Open the box, pull out the element, and string as many in series as necessary for your pack voltage. In my case, I’ll probably be using 3 of them. I’ve got two more of the Holmes heater pictured in the link coming from an eBay seller, for $11 each.

I tinkered again today with removing various bits from my dash before pausing to read the instructions in the shop manual. Especially the part where they say to remove the passenger side fender and then jack up the truck and remove the wheel. And then I decided, it’s December 24, I’ve got better things to do today.