68 GTX Fan Switch

[69L48Z27]

Next question....

The fan in the car is not operational. I started at the fuse block and I have power, next moved to the switch. Once I got eyes on the switch I saw there was a bit of melting on the connectors. Out comes the switch, looks like it saw a little extra resistance at some point. Not totally wasted, I opened the switch up to find contacts corroded and the grease had turned hard. Cleaned the switch up and reassembled it. Here's the part I need some direction. I would expect that when I test continuity the switch position is should only pass current through one set of contacts. On the last switch position I get two wires tha have continuity. I took the switch apart and I can't see how it's even possible for it not to do this. The plate inside would need to make contact with both.

Should I have continuity on two wires in the last switch position? Can't understand how it would slow the fan down if its not.

Oh, one other question. Can someone meter the ohms across a good fan motor? Mine reads ~300 ohms. Before I put power to it thought I would ask...

Thank you.

 

[oldbee]

Never saw a fan switch on a '68!!! Seriously, you have excess amperage. Running a relay 30-40amps. Too small wiring? Need more info for all of us here.

 

[oldbee]

Unless you're talking htr. motor. Maybe the switch took a dump.

 

[69L48Z27]

No unicorns here, the radiator fan still runs on a belt.

Talking about the heater fan switch in the dash.

 

[oldbee]

I think your motor s toast..Or htr resistor really did something weird.

 

[bigmanjbmopar]

http://www.ebay.com/itm/1968-70-DOD...ash=item1a0bd12e0f:g:4q8AAOSwhkRWg11T&vxp=mtr

 

[69L48Z27]

Saw those. Wasn't real excited about dropping over $100 on a new switch.

Switch is rebuilt and I would trust it as long as the rest of the devices are good like the fan.

I'm trying to understand what the switch is supposed to do when operation, meaning what output wires have continuity when the switch is moved.

 

[bigmanjbmopar]

Maybe this will help

 

[69L48Z27]

Thx. I do have diagrams. Still trying to determine if two wires should have continuity at the same time.

 

[bigmanjbmopar]

Did you meter the resistor value? is that the continuity you are seeing?

 

[69L48Z27]

Everything through the switch it's self is fine resistance wise. No issues there.

The black lead is the source wire from the fuse block.

Switch in position 0 - no colored wires have continuity.
Pos 1 - 1 wire for highest speed has continuity.
Pos 2 - 1 wire for medium speed has continuity
So far so good.
Pos 3 - 2 wires have continuity, both medium AND low.

My question - is this normal? When I had the switch apart it appears it cannot work any other way but I would think each wire should carry its own voltage to the heater fan resistor plate that is on the heater box. BTW - the thing on the heater box meters out properly and is in good working condition.

Thx.