# Defrost/heater fan not working **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [September 17, 2008, 3:23pm UTC](https://community.cartalk.com/t/defrost-heater-fan-not-working/19685 "2008-09-17T15:23:38Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![harteau](https://avatars.discourse-cdn.com/v4/letter/h/c0e974/32.png) [@harteau](https://community.cartalk.com/u/harteau)\ **Post date:** [September 17, 2008, 3:23pm UTC](https://community.cartalk.com/t/defrost-heater-fan-not-working/19685/1 "2008-09-17T15:23:38Z")
1999 Ford Ranger XLT defrost/heater fan does not engage when switched on(in any speed)yet sometimes it does and other times it doesn’t, nor does it go on/off/on while driving. One day I get in and it works, next day I get in and it doesn’t. Selector switch feels just like it always has, just doesn’t turn on fan. I’m a decent wrench with some confidence. Would like to know what to look for…perhaps loose plug or connection, switch that’s getting tired??? ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [September 17, 2008, 4:23pm UTC](https://community.cartalk.com/t/defrost-heater-fan-not-working/19685/2 "2008-09-17T16:23:09Z")
I would suspect the blower relay as the cause of the trouble first. It is located in the battery junction box. You may be able to swap it with another relay that is the same type to check it out. ---
**Author:** ![Triedaq](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@Triedaq](https://community.cartalk.com/u/Triedaq)\ **Post date:** [September 18, 2008, 1:25am UTC](https://community.cartalk.com/t/defrost-heater-fan-not-working/19685/3 "2008-09-18T01:25:39Z")
Tap on the blower motor with a stick. If the blower fan comes on, you have a defective motor. If it doesn’t, use a test light to see if you have power at the blower motor.