Porsche Enthusiasts Club Forum

The heater control in my 944 S2 now only works when switched to 4..... 1 2 3 don't do anything.

Anybody had this problem or have any suggestions?

Spen

I think that there is a set of resistors somewhere which has probably failed. They are not used in position 4 i.e full power which is why it still works.

any idea where they are located.

Spen

Underbonnet, under the plastic scuttle panel,




Pin out for 5-Way connector =

Pin 1. Brown/Black Gnd from Blower motor to resistor pack...this wire gnds the motor. Note :- example :- if you put it directly to gnd (as your 4th speed position does on the switch, you will get Full blower speed......

Pin 2. White Output to Position 3 (3rd speed) of Blower Switch. N.B this is switched to gnd by the blower motor switch.

Pin 3. White /Green Output to Position 2 (2nd speed) of Blower Switch. N.B this is switched to gnd by the blower motor switch.

Pin 4 Brown/White Output to Position 1 (1st speed) of Blower Switch. N.B this is switched to gnd by the blower motor switch.

Note:- Full speed (4th position)....which you have,,, bypasses the resistor pack to the mtr,,,,,,,,,,If you have all the Inputs from the switch pack, and suspect the resistor pack (carefully inspect the connector as a poor connection will reduce it to a blob of melted plastic),,current is quite high (2.5mm wires are capable of 20amp continuous draw).

The resistor values = Series accumulated to 1.65 ohms for 1ST Speed. 0.65 for 2ND speed, and 0.25 ohms for 3RD speed.


Hope this help's

Cheers

Top man.

Thanks Derrick.... i'll let you know how i get on.

Spen