Interior fan not working

Hi

I have a MK1 91 Caddy and the interior fan isn't working on any speed, is there a fuse as I cant work out which does what and is there anything I can check to eliminate things???

Depending on if you have a/c or not.

The most likely failure is the Switch, motor or connector that is on the left hand side of the air box.

To eliminate the switch you need to remove the heater Fascia and switch levers.

On the switch there is a Black and red feed wire, measure that for 12V if you have 12V on it then the fuse
@F14 is good, no voltage indicates that f12 is probably blown.

To eliminate the Switch
You can use a Jumper and go between the Black/Red wire to any of the others on the Switch if the fan comes on then you have a bad switch.

OR

You have a toasted ground wire to the motor.
On the Left hand side of the heater box there is a White or yellowed connector with 4 or 5 wires depending on a/c equipped or not.  That connector has been know to get corroded and the wire connections get burnt.

If you have Browning on the connector then your Ground wire may not be making good connection.

The ground wire is coming off the firewall, and you can use an insulated pair of Male/female spade connectors and go around it with a new ground to the firewall.

The Ground for the motor is not coming from the switch, the switch is used to Shuttle voltages from the fuse to different parts of the motors resistor.

Good luck.

If you have a 4 speed fan, then you also have the a/c relay and a fuse at s1 usually the 4th speed is outside of the normal fan switch and controlled buy the relay.