David:

The speed control is actually a transistor switching unit that grounds the blower windings on a duty cycle. I'm not sure of the wiring, so don't connect battery voltage to anything there! I seem to remember a connector on the side of the heater box inside the car that is probably the blower motor, and you could connect the battery voltage there.

A test lamp will have a 12V bulb, so you won't get anything more than a very dim glow at 7V no matter what the amperage, and since that is a signal line anyway, the lamp will never light. You will have to use a voltmeter to see what the voltage is.

I'll try to dig up the instructions for removing the heater box to verify the connections.

You should try a search on blower regulator/speed control, I'm sure this was discussed quite a bit a couple years ago.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!