First thing to try is pull the plug from the thermo switch and jump the two
connections together and see if the fans run. If so the switch is bad.
Good question though. I'd be interested in the answer also. I know there are
two different grommets available for the switch, one which goes deeper into
the rad for more holding power, but expensive at about $15 bucks. On mine I
use a thin electrical tie through the rad around the back of the switch to
hold it in.
----- Original Message -----
From: "Howard Battan" <email@example.com>
Sent: Monday, July 11, 2005 11:05 PM
Subject: MGB cooling fan thermostat
> Hey, all, on my '79 MGB, the radiator cooling fans don't come on, even
> though the water gets hot enough to boil over. In the Moss catalog, there
> are two thrermostats listed, along with two different grommets and a
> clip for late model cars. I was told by on mechanic to be sure to use the
> clip to prevent launching the thermostat at high pressure. My question
> is -
> can I use the early model thermostat and grommet with the late mode clip?
> The reason I ask is I was told I probably could, and the early model
> thermostat is much cheaper than the late model.
> Thanks for your help.
> Howard Battan
> '79 MGB
> '57 MGA