Hi!
I have now successfully completed the installation of a Webasto Thermo Top C parking heater in my '97 4.6. It was fairly involved, as the interior blowers don't have one terminal grounded when the ignition is off. On most cars, one side of the blower is grounded and the positive terminal is regulated to control speed. This car also has two blowers, which further complicated the issue. I solved it using a DPDT relay for each blower, to switch them from the BECM-supply to the webasto when it fires up.
The blowers are industrial-size; when I first tested it, they blew a 20 amp fuse on start up. I plan to install a PLM speed controller to bring down the power consumption and decrease the amount of cold air being pulled in from outside.
Anyway, it works like a charm, so if anyone plans to attempt this installation, I'll be more than happy to give you some pointers.
Cheers
Henrik
I have now successfully completed the installation of a Webasto Thermo Top C parking heater in my '97 4.6. It was fairly involved, as the interior blowers don't have one terminal grounded when the ignition is off. On most cars, one side of the blower is grounded and the positive terminal is regulated to control speed. This car also has two blowers, which further complicated the issue. I solved it using a DPDT relay for each blower, to switch them from the BECM-supply to the webasto when it fires up.
The blowers are industrial-size; when I first tested it, they blew a 20 amp fuse on start up. I plan to install a PLM speed controller to bring down the power consumption and decrease the amount of cold air being pulled in from outside.
Anyway, it works like a charm, so if anyone plans to attempt this installation, I'll be more than happy to give you some pointers.
Cheers
Henrik