<VV> Convertible Top Pump Wiring

[FrankCB at aol.com]

Geoff,
    Not having a Corvair wiring diagram available, I'll  have to base my 
explanation solely on your description.  Apparently  the stock Corvair pump motor 
has TWO windings in OPPOSITE directions with a  common ground that goes from 
the motor to the car chassis.  The stock SPDT  (single pole double throw) 
switch simply sends +12 volts to EITHER of these  windings, one of them moving the 
top UP and the other DOWN.  The newer  motor has simply ONE winding.  But its 
associated switch is a  more complicated DPDT (double pole double throw) type 
that REVERSES BOTH of the  +12 volt AND the ground connections to the motor.
    The easiest solution, of course, is to simply  change over the stock 
Corvair switch for the later one and make the wiring  changes.  Alternatively, if 
you can't install the newer switch, you could  add a high current relay that 
would serve the same purpose.
    The important thing to remember is that you need  the relay and/or the 
switch and the wiring to remotely accomplish exactly what  you did with your 
jumper wires. 
    Good luck.
    Frank "sparky" Burkhard 
 
In a message dated 10/22/2006 10:25:02 PM Eastern Standard Time,  
geoffj at unm.edu writes:

It was  mentioned on Corvair Center that a late model (80's or so) GM 
power top  pump would work in place of the stock unit for an early 
Corvair  convertible.  

Here is the question. We went and bought a motor  out of a late 80's 
Sunbird today. Put it in and primed the lines. It works  great with a 
battery jumped to the two wires. Puts the top up or  down.  With the 
wiring connected stock, it will not work. It is  obvious it does not 
ground. The new motor has no ground wire, and acts as  if it does not 
need one. As in the wiring from the car it came out of  swapped the 
polarity in the switch, providing +12 and ground through the  switch, 
swapped per wire depending on switch position.. The switch here  just 
provides +12 to either wire depending on switch, with ground at the  
pump. So did they change something? I tried grounding the motor and it  
would not work. The pump we got today looks identical to the ones listed  
as working on 60's GM's.

Can someone explain the wiring on a stock  unit?  
The pain is that now the lines are primed, I can not put the  top up or 
down without jumping the pump.   Can not put it up or  down manually like 
I have done for years.

Thanks
Geoff  Johnson