w114 no defroster

[huffandpuff]

turn defrost knob get no power fan doesn't turn on whats best way to troubleshoot and fuses go where see nothing in large fuse box label

[Mike D]

If the A/C switch, if so equipped, activates the console blower then check the change-over micro-switch mounted on the side of of the center console above the accelerator linkage.

[huffandpuff]

micro switch ??? see this round item with lines hanging off ?? vac lines and some square box wished there was article on this climate control stuff is there a relay for defrost switch ??

[Sugar Bear]

IIRC microswitch/changeover switch is above the accelerator pedal. Check and CLEAN the fuses in a small brown square box on the firewall just off center toward the passenger side. It is separate from the main fuse box.

Good luck!!!

[Idle]

Get out the volt meter and find out if there is power going into the fuse for the A/C. Then see if there is power going out. If not then change the fuse. This is easier to check that if power is coming into the switch.

But if power is coming into the switch and no power is coming out then you have to replace the switch. Careful here. It sounds like you have the switch with the vac lines to control the blend doors and also the thermostat. That long thin wire looking thing that seems to go nowhere is your 'thermocouple' that tells your compressor switch when to come on. So don't bend it too much when taking the switch out to test it.

That little switch controls a lot of things: Blend doors, fan speed, compressor off/on. So handle it easy.

[Mike D]

The A/C fans and the defroster/heater fans are completely separate units on the /eights.

The power going into the A/C control knob/switch is for compressor control not fan speed.

[Idle]

Originally Posted by Mike D

The A/C fans and the defroster/heater fans are completely separate units on the /eights.

The power going into the A/C control knob/switch is for compressor control not fan speed.

Thanks, it's been awhile since I worked on a 114.

So is the a/c fan behind the passenger kick panel like on a 108?

[Mike D]

Nope. It is mounted to the air box IN the center console. It is a dual turbine affair.

The heat/defrost blower mounts to the lower center part of the firewall/floor area. It is quite an ordeal to replace. I've got a thread on its replacement somewhere on this forum.