Need help with buzzing furnace relay!

[RSF F101]

I have a old norton 20kw furnace. Joined with an RSF wood furnace.
A relay in the Norton has been buzzing for a while. (Controls the FAN I think).
Old relay had NO numbers on it. Found one supossedly new that looked exactly the same. Installed it and it buzzes as well?
Could it be something eles causing the buzzing/humming? Maybe both relays are bad?
Any help would be great. Live way to far out to get a service guy here!

 

[xshmoox]

Could have weak incoming coil voltage the bottom left and bottom right terminals or if it’s controlling the fan the fan amp draw could be getting to high for the relay, possibly fan motor could be on its way out, or if the fan has a run capacitor on it, that could be shot or getting weak causing a higher amp draw.

 

[RSF F101]

Could have weak incoming coil voltage the bottom left and bottom right terminals or if it’s controlling the fan the fan amp draw could be getting to high for the relay, possibly fan motor could be on its way out, or if the fan has a run capacitor on it, that could be shot or getting weak causing a higher amp draw.

Ok. Geat info Thanks. Any suggestions on how to diagnois. Check the amp dram on the fan? I did have to replace the run capacitor a short while back. Can i test the coil voltage on those terminals?
Thanks so much for the help.

 

[xshmoox]

Yes you can check coil voltage on the bottom 2 black wires on that relay. I would probably check amp draw on fan as well. And if your voltmeter has the capability would be wise to check capacitor again. These capacitors that are out there these days are mostly junk and you’re lucky if you get 5 years out of a generic replacement one

 

[RSF F101]

Ok, great will try to get that done. From what you have said! I think the fan my be suspect. Probably close to 20 years old!
Thanks again!