This past weekend I installed a 1500 watt heater in the Fastback.  Last night we tried it out on a rainy night and it worked great!  Instant heat.  I’ve got it plumbed into the defroster ducts at the moment, since seeing where you’re going is a priority.  I may later add some ducting so it will warm the passengers as well.

In most EV conversions, the heater core is replaced with a ceramic heating element and everything else is left stock.  Since older VW’s don’t have heater cores, a complete heater is needed.  Fortunately, Canadian EV offers just such a thing and they are a great company to do business with.  Here is a photo of the installed unit.

Heater installed

The black box with “240” written on it is the heater itself, with a fan housing below it.  You can see one of the two ducts on the right, going to the defroster tube.  There is a contactor behind that tube – this is a switch that turns on the 288 volt power supply when the heater switch is flipped.  By using a contactor wired into the heater fan switch, there is no risk of creating heat without air movement, which could cause a fire.  The orange, yellow and red wires are for the various fan speeds – they go to the dashboard switch.

The entire unit is mounted to the front cab wall beneath the dash.  In the Fastback, this spot is occupied by a fresh air blower which I removed.  The fresh air inlet is now covered with a piece of ABS plastic which I cut to match the profile of the removed blower housing.  A rubber seal is caulked in place to prevent any water from getting in.  It all works fine – we’ve had a lot of rain lately and everything is dry.

The heater is controlled with one switch which I mounted in a hole where the fresh air controls once sat.

Dash with Heater Switch

The entire job took about four hours, including removing the fresh air blower.

My conversion project is essentially done.  There is still some BMS work needed, but I have been able to successfully charge and balance the batteries without the BMS.  I still want to get it working right, but at least the car is a reliable all-weather driver now.


Explore posts in the same categories: The Project Log

7 Comments on “Heat!”

  1. Eric Says:


    I have a 68 Karmann Ghia that I am going to convert to electric and will be buying or building a heating system like this one. Two questions: 1. How much did this system cost? 1. To add more ducts for passenger heat, do you cut more holes into the heater housing and duct in more tubing, or do you put a “Y” into the defroster ducting to split the air flow in two? Great site. Thanks for the info.

  2. rhamje Says:

    Hi Eric,

    The heater cost $477 (US) delivered. I have not done this yet, but I would put a “Y” in the ducting to tie the tubing to the heater. The heater includes two duct outlets that you could mount in or under the dash for passenger heat – these have little lids that will close them off. So if you split the airflow with a “Y” and closed the passenger outlets you’d have 100% defrost. But there would be no way to shut off the defrost and get 100% passenger heat.

    Another way to do this would be to mount the electric heater in the engine compartment and tie the two outlets directly to the original VW duct-work at the firewall. If your original controls are still working you’d do it the same as when you had a gas engine. Would be a more “stock” solution. I could not do this because I used my heat ducts as conduits for the wiring.

    BTW – I have found that this heater is very powerful and even with defrost only it warms the whole car pretty quickly. Might be a different story if it was -10 outside, but at 25 degrees it works great.

    Good luck!

  3. Gary McNeel Says:

    Great job. I have a 71 Beetle with a blown engine and have been debating a conversion. I was also considering the Thundersky batteries, but that may be a bit pricey for what I want to do. Keep up the fun and thanks for the postings.

    • rhamje Says:

      Hi Gary,

      Money is always an issue. But a 71 Beetle is a great candidate if it’s an otherwise good car. You don’t need a motor mount and if you’re willing to give up the trunk (or back seat) you would not need to do any fabrication at all. I’d use the new HPEV AC drive system with Curtis controller at 96 or 108 volts – you should be able to build that with lithium batteries for under $15K. Much simpler than what I did.

      The one thing about an EV – it is FUN! Fun to drive, fun to show off.

      Good luck!

  4. Hector Says:

    what’s the brand/model of the heater?

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