Cadillac Repair: Interior Vent Fans Stay On, amp fuse, rubber grommet

Question
Rob,

When I turn off the ignition and pull the key the fans still blow air continuously.  I didn't want it to kill the battery, so I pulled the fuse under the hood.

At an auto part store today, they told me to buy and try a new relay.  But that didn't work.  

I saw an earlier post you said you could bypass it and it would stay on high.  That would be fine with me until I can get a more permanent solution.

Thank you for your help.

--Cain
'92 Cadillac Sedan Deville

Answer
Hello,

You appear to have the same problem many Cadillac owners have had since the early 80's in which the blower resistor module malfunctions.

You can pick up a toggle switch at a parts store. You can hook one side of the switch with ignition power. run the other side of the wire under the hood. If you drill a hole through the firewall, use a rubber grommet in the hole you run the wire through. Should be 10 or 12 gauge. Install an inline fuse holder with 20 amp fuse. Run the remaining wire to the blower. The reason you use switched power is so you don't forget to shut it off and have the battery go dead.

Rob