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cpartridge · Nov 2, 2007, 11:16 AM

We just bought this house and the fan runs continuously, I got a new limit switch as the old one had a broken auto/man switch, and the relay was burnt out. The old relay was 5 wires the new one is 6 but there is no diagram on the old one.
Wiring is the worse thing for me to do, anything else is fine.

I have a hot wire to the fan, a second white wire from the relay to the fan, a blue wire from the fan to the relay, a blue wire from the limit switch to the relay, a white wire from the limit sw to the relay, and a hot wire to the relay.
I am just gettign confusewd and now have no heat here in Canada.
Any help would be appreciated.
Thanks

hvac1000 · Nov 3, 2007, 08:33 AM

Post wiring diagram for old and new switch. We have no idea how to wire it until we see what you have.

cpartridge · Nov 3, 2007, 09:13 AM

Part of the problem is the missing diagram for the old relay, I am stumped at why both the common and the hot run through the relay and the additional direct hot to the fan motor. Because the fan runs continiously I believe the old relay was wired improperly, one contact was also burnt out. Teh wiring diagram I do have for the furnace doesn't show the relay. It is an 1970 model Olsen, made by DMO Industries in Richmond BC, but I have a Chrysler Airtemp 4200 manual, they look almost exactly the same.

labman · Nov 3, 2007, 01:08 PM

Try doing a search on the net for both the old and new relays and find how they are wired and give us the links. Who suggested the new relay? Did it come with a wiring diagram?

KISS · Nov 3, 2007, 04:45 PM

Is this heat or heat/AC?

5 wires including 24 VAC for coil on relay?

How many speeds does the fan have?

cpartridge · Nov 4, 2007, 08:33 PM

I found an old bill today in a stack of stuff from previous owner, it si an Olsen Duomatic 150M BTU Hiboy, then it says 2 speed relay, but the tag on the burnt relay is missing, I had to replace the fan limit SW at the same time as the auto/man SW was busted. The manual I have been following was for the original furnace not this one. Anybody know where I might get a wiring diagram?

labman · Nov 4, 2007, 08:55 PM

Go buy a 4 wire relay. Connect the limit switch to one coil terminal, and the other to the common of the transformer. Connect the black from the house to the line terminal. Connect the one motor lead to the load terminal. Connect the other motor lead to the house neutral.

cpartridge · Nov 4, 2007, 09:11 PM

Thanks I'll try that in the morning, it's the 5th wire thta's got me confused.