Proper fuse for Blower Motor Control Module and Blower Fan

[Clay_Bee]

I wired a sealed mini-blade fuse holder in-line between the blower fan and the BMCM. What amperage fuse should I use for this? As the blower motor ages I can count on its draw increasing. Another post suggested that these blower motors throw shorts on occaision, and causes the BMCM to act as a fuse and blow. I'm thinking 20amp should do it.

Clay

[STM]

Fuse # 3 on the right under the hood near the firewall is a 30 Amp fuse that provides power to the blower control assembly on the red wire. I'm not convinced another fuse will help and it may create nusance fan outages. The blower motor should not draw more current as it ages unless the bearings begin to go. Besides a fuse is an extremely slow acting device compared to the solid state unit you are trying to protect. Since you already have the fuseholder wired in, I'd start with a 25 amp fuse & if that doesn't blow, fine. Of course the most likely time for it to blow is on the hottest day of the summer when the blower is running on high for awhile. Be sure to use heavy enough wire and a fuse holder that can take 30 amps without melting. I'd use at least #14 wire. Blowers take a lot of power on high, but the controller is designed to handle it. There may have been a problem with your controller completely unrelated to the blower current draw.

[Clay_Bee]

I bought a mini-blade fuse holder at Wally World. Has a heavy guage wire. I don't like crimped connections, so I twisted and tinned the connections with solder. The holder is located right were the wire bundle enters the relay center cover, and is sealed with a snap over cover. The access is so easy, I'm starting with a 20 with a 25 as spare in the glove box.

[STM]

You should be OK with that setup. Most people can't solder, but it certainly does help. I'd keep a 30 amp fuse handy just in case. Fuse ratings are not exact. Of course the blower motor draws considerably less than max amps when it is not running on "high".

[STM]

BTW that is great that the module did the trick. Hopefully you will get 13 years use out of this one.