Referring to topic
http://www.sl113.org/forums/index.php?topic=22827.msg163355#msg163355 , I posted my set up for an auxiliary electric pusher fan for both the radiator and AC condensor that is triggered by a thermostat and/or the AC compressor. It is also wired to run for 3 minutes after engine shut off.
Recently, I read an old post by Dan Caron where he referenced the electric water pumps used by MB in the 1980s.
I decided to plump one into my heater bypass circuit and to have it run when the car is idling, as well as run during the 3 minutes that the aux fan runs after engine shut off.
My heater bypass setup uses a 3-way valve on the intake side of the heater, so I put the pump on the right side. This is the pump I used:
http://www.amazon.com/gp/product/B001CO6ZHA?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00 .
To reduce heat soak, the pump is triggered through the same falling edge relay that controls the aux fan upon engine shut off. It is very nice to watch the temp needle go down, rather than up, when I shut off the car in the hot Florida sun.
To keep the temp at 180 when idling in traffic more than 10-15 minutes, the pump is triggered using the microswitch setup originally designed for the 2nd solenoid on the FIP (in some models).
I found the updated version of the original microswitch at
https://www.alliedelec.com/johnson-electric-v9n/70162342/ . My AC system uses an idle kick-up solenoid, but the microswitch has enough play in it so that the bolt that pushes its pin can be adjusted to keep the pump on when the solenoid kicks up the idle.
For the winter or driving up North, I installed an on-off switch for the pump for when the 3-way valve is open to the heater core.
1st picture: shows heater bypass setup, with 3-way valve and electric pump.
2nd picture: shows the pump.
3rd picture: shows the microswitch
