Last night I pulled out the blower fans and sprayed WD-40
into them, which cured the squeals.
I noticed they are wired such that disconnecting one of them
causes the other to power up noticeably. Also, since the
fans always come on ‘‘low’’ whenever the ignition is on, it
seems someone has re-wired them at some point.
I cleaned the switch and got the ‘‘high’’ function working,
but I can’t ever turn them off when the car is on.
How are they supposed to work?
The airflow seems weak; was it adequate when new, or where
standards different back in 1973?
I want to know if I should replace them. Also, is there a
source for fan to firewall gaskets? Mine have crumbled
away.
Thanks!–
Chris Los 1973 XJ6, 1996 XJ12
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from thetopdogg sent Sun 12 Feb 2012:
Ignition supply from fuse number three goes to terminals 3
and 4 on the switch.
low speed is from terminal 1 through the resistor to the
motors.
High speed is from terminal 2 to the motors.
Obviously when they are switched off there should be nothing
on terminals 1 and 2 at the switch.
There is only one resistor, so if a motor is disconnected
when they are switched to low speed the remaining motor will
speed up due to reduced voltage drop through the resistor.
I wouldn’t put them back in after ‘‘fixing’’ bearing squeal
with WD40. WD40 isn’t a good lubricant for the bushes,
dismantling the motors and soaking the bushes in engine oil
is a better option which also gives you the chance to check
the commutator and brush lengths.–
The original message included these comments:
Last night I pulled out the blower fans and sprayed WD-40
into them, which cured the squeals.
I noticed they are wired such that disconnecting one of them
causes the other to power up noticeably. Also, since the
fans always come on ‘‘low’’ whenever the ignition is on, it
seems someone has re-wired them at some point.
In reply to a message from sparx sent Sun 12 Feb 2012:
If the car is air conditioned, there is a contact from a
microswitch attached to the Ranco switch that turns the fans
on low if the AC knob is anywhere but full off. On later S1
cars (including this one, a 73) the motor is fed via a
second resistor from the microswitch. This ‘‘low’’ speed is
actually lower than the low speed obtained from the rocker
switch on the centre fascia (there are 3 speeds altogether).
On earlier cars, the Ranco microswitch simply duplicates the
low on the fascia switch.
So, with any AC-equipped S1 car, a misadjustment, failure,
etc of the Ranco-mounted switch ans associated circuit can
cause what is described here, with no fault in the actual
fan switch or its circuitry. If no AC, ‘‘never mind.’’–
The original message included these comments:
low speed is from terminal 1 through the resistor to the
motors.
High speed is from terminal 2 to the motors.
Obviously when they are switched off there should be nothing
on terminals 1 and 2 at the switch.