Hi All,

I'm the proud (relatively) new owner of a 68 Sedan DeVille - had it a couple months and love the thing so far - great car. Been reading a bunch in this forum - an incredible amount of knowledge in here.

As of a couple weeks ago, I seem to now have a blower motor on my hands that never wants to quit. Whenever I take the car out, come back, park it and turn the key off - the blower won't stop no matter what I do (I've actually taken to disconnecting the battery's negative feed to stop it entirely so it stops draining.

I *believe* the culprit is a faulty blower relay from the reading I've been doing (shop manuals are awesome!) but am not 100% sure, as I'm a newbie and not sure I have the electrical diagram completely understood.

Anyone run into this before or have any thoughts?

Thanks much!

Its either the relay, or the coil wire is always powered. Bruce Roe CLC # 14630

It sounds like the relay. I don't know where it is located though; it's usually close by in that general area. It might be easier to unplug the blower until you figure it out instead of removing the battery terminal.

It's kind of curious as to how the blower gets power with the ignition off. The later Caddys have a residual-power relay, which keeps power on for some things like the radio, power windows etc, with the ignition off, until a door is opened. Don't know about an older one like yours.
You need a manual with electrical schematics in it. Try Ebay for a factory manual. It will pay for itself very quickly.

I have seen a alternator diode short out and back feed power and keep things like the blower on...try taking off the wires to the alt. and see if the blower stops..

Thanks for the thoughts on this, everyone. I have made the upgrade on "which end of the wire I'm unhooking" as the immediate work-around :)

I do have a shop manual, but my comprehension of the electrical schematic is the weak point...... The previous owner had pretty much every wire in the engine wrapped in a ton of electrical tape, making deciphering the wires kind of a mess, so I'm going to avoid jumping into that if possible, but sounds like the relay is at least a reasonable guess here......I'll check into a replacement if it's not too expensive. The relay is attached to the back of the dashboard by a screw or two, so it's not looking like a tough replacement procedure.

Absolute worst case scenario - I've not used the climate control to this point anyways, so may just live without - my primary concern is it draining the battery after ignition shutdown.

Thanks!

Oh, you have CLIMATE CONTROL. I don't have a 69 Cad manual, but my 79 CC blower control is quite different from my other non CC cars. You really must get a manual to deal with this system. Bruce Roe CLC # 14630