Extracting the heater core
By Mike Chancey
January 13, 2004
In response to the question: "I'm wondering if anyone has tried
getting at the existing heater core through the firewall.
I think this would ultimately work out better."
Ah, folks, why is there such an obsession with finding other ways to get to the heater core?
They are designed to be replaceable, and not by rocket scientists, just regular guys with some
technical training and access to good instructions. The problem is far too many people are
using those cheap over the counter service manuals and they don't include enough of these instructions.
The Chilton manuals and so forth are too simple, too general and too vague. Buy the real manual from
the maker of your car or copy the relevant pages from a library copy. I bought the Helm's manual for
my Civic. About $65 as I recall. Best investment I ever made.
Many cars have "tricks" to access the heater core. For example, on the Fieros (at least the later ones)
you can access the heater core through the passenger side speaker opening on top of the dash. Without
the proper manual you would never even suspect this.
Converting a car to electric is a big job, but anything worth doing is worth doing right.
(Or in my case doing it over and over until it is right) Don't hack up your car just to shortcut things.
On my Honda I had to pull the whole dash to access the heater core. It was actually far easier than it looked.
While it was out I was able to do a lot of wiring that would have been all but impossible with it in place and
clean out 100,000 miles worth of crud.
The whole secret of a good conversion is to plan ahead, have the proper materials, tools, and manuals
on hand, take your time, and end up with something to be proud of. The other big secret is use
There are a lot of sharp minds here, when you have a question just ask.