FWIW Department:
Not to long back, a lister posed the question about installing a relay in
the heater blower circuit, and it's effect on the speed of the blower
motor. (sorry, can't remember exactly who originated the thread)
I haven't been exactly happy with the heater blower on my GT for a long
time, so I thought I'd give it a try. Used a relay from a aux. driving
light kit and installed it, mounted next to the heater box, on the
firewall.
There is a marked increase in the speed of the motor with the relay in
place. To double check, I pulled the fan switch wire from the relay and
jumpered to the motor + wire. The motor speed audibly decreased, but
immediatly raised again when the relay was re-connected.
Not being an electrical genius, I can only surmise that the skimpy
wiring to and from the fan switch and to the motor simply isn't
suffecient to carry the current. With the line power circuit through the
relay now being 10 ga. wire, it seems to work much better. As a side-bar,
I've also noticed the voltage drop, as registered by the on-board voltage
meter is much less than before. Pre-relay, when I turned on the blower,
the voltmeter would drop by 1 1/2 - 2 volts. Now it's somewhere in the
range of 1/2 v.
Am I correct in my assumptions? Or is there something else that I might
be missing here.
Rick Morrison
72 MGBGT
74 Midget
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