Naturally I haven't driven ol 1343 much this winter. Part of the reason was
the heater didn't work. I finally decided to figure out what the problem was.
The heater valve is normally open and the vacuum holds it closed (kind of
backwards if you ask me). For the summer, I had the valve hooked directly to
the
engine vacuum. When it started getting cold, I connected one of the hoses
from the under dash switch to the engine and the other hose to the heater valve.
Well I found out that it makes a difference which port on the under dash
switch you connect which hose to. When the temp control is moved to heat the
switch is supposed to block off the port connected to the engine and open the
port connected to the heater valve to let the vacuum out. If you have the
hoses
reversed then moving the control to heat blocks off the port to the valve thus
trapping the vacuum in the hose and keeping the valve closed. It also opens
the port to the engine causing a small vacuum leak.
An easy way to check if they are connected right is to disconnect the hose
from the valve, move the temp control to heat, and suck on the hose. If you
can
create a vacuum then the hoses are on the wrong ports.
Marvin
#1343
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