No Interior Fan and No Snow Flake
 

Hi I’m a new owner and I’m looking for a hand with my first problem.

It is a 2003 with automatic climate control. My HVAC fan stopped working over the weekend while I was driving. The fan/blower does not work at any setting (low speed, high speed, auto, manual, or defrost). The AC snowflake symbol does not light up either. Also new strange behavior, when in manual the fan speed bar graph will change by itself but obviously the fan is not responding. There are no other symptoms, all other accessories are functioning.

I did some reading and it sounds like one of the following:

• Bad relay. (not sure if this would account for the AC and manual fan speed changing)
• Bad control unit.

After I check the relays, are there any other things I should check before moving to replace the control unit?

The car has 12k miles on it.

Thanks,
Dave

Just had the same problem on my 2003 986S. Turned out to be the electronic half of my ignition switch. New switch from pelican, a couple of hours of my life and a trip to the chiropractor later and it was all working again.

In my case I confirmed it as when I turned the key a fraction of a degree (counterclockwise in my case) made the AC work again. FYI when my AC didn't work neither did my headlights and other electrics

CB

Thanks I'll look into that. Doesn't sound the same - everything else is the car working fine.

The fan/blower does not work at any setting (low speed, high speed, auto, manual, or defrost). Mine acted in just this way


The AC snowflake symbol does not light up either. Mine acted in just this way

Also new strange behavior, when in manual the fan speed bar graph will change by itself but obviously the fan is not responding. Not sure what you mean by "by itself", but on mine could make the bar graph change with no change in output of the fan, which wasn't worling at all

The car is new to you (congrats!). Ignition switch is absolutely notorious for causing weird stuff to happen. It's $15...replace it and report back (that your A/C and fan work again!).

Lots of write ups online, including one from me on this forum. Well worth reading, I know it saved me a lot of $. Porsche dealer didn't sell the cheap part anymore ($15-30, depending on where you buy it and who makes it, mine was a mid price part from pelican). The dealer only stocks an improved part at about $270 that is a more time consuming install. So a trip to the dealer will set you back about $500 (270 plus a couple hours of labor at the dealership rate). My first one lasted 13 years so I'm willing to do the job again in 2029 for the savings. This is one of those tasks that can reduce the cost of Boxster ownership dramatically

Thanks for the help.

I will update as this develops and hopefully when it is fixed.

After 500 miles of no fan or AC it's working again for no apparent reason. Ignition switch seems likely.

What happens when you jiggle the switch or turn it slightly?

Wiggling the ignition key, both running and not, does not cause any symptoms. It's functioning normally for now.

It's not fixed....You have a classic sign of a bad ignition switch. Again, since the car is new to you, change out the electrical portion of the switch and you'll solve your problem and know the status of you ignition switch. This is a good DYI...a little challenging but not that difficult.

Back in 2011 bought a 2 owner local 98 Boxster for $4,800. The car was dirty but not really neglected. The owner was tired of paying big $ to have all the little things things fixed.

Two problems he disclosed was AC that worked great sometimes and other times would not work at all and a stereo that did the same thing. Before buying the car, I told him about the ignition switch, to give him a chance to see if wanted to try to get the car fixed. He was done.

The day I bought the car, the AC and stereo were working fine. The next day, the AC wouldn't come on but the stereo worked. Later the same day, good AC and no stereo....you get the picture.

I purchased a new ignition switch from local NAPA dealer for $15. Having gone through this drill on my 2000 Boxster, the R/R took about 20 minutes. Both problems solved.

I have bought three other CL Boxsters since that one in 2011. I replace the ignition switch each time just so I'm not chasing my tail trying to solve weird problems. Cheap insurance!

Update - Happened again just before my battery died. New battery installed and all is well (for now).

Ignition switch purchased and on the to do list, but was thinking that a low voltage level might also cause the HVAC control to flake out.

Nope. It's still your ignition switch (I promise).

Working on the same problem. It's not your ignition switch if your rear window defogger works, or your windshield wipers work, or your headlights work.
I was down to the heater resistor and blower. The heater resistor can be bypased by pulling the plug. (You'll have to take out the glove box Passenger side vent and Passenger side vent duct) the resistor is red and above and to the left of the blower. The plug can be released by pressing in the 2 inner tab and pulling it out, or removing the resistor for better access. Make a jumper out of a fuse or a short piece of wire and 2, 1/4" spade connectors. Turn on your key, if the blower runs it's your resistor. If the blower does not run check for 12VDC on the Blue Black wire on the blower plug and the brown red wire. If there the blower has failed. If the 12 VDC is not there check the heater relay No 18 bottom row left relay under dash. My blower died.

As a note the AC snow flake will not light if the motor is not running.

After removing the blower found a rusted broken spring that pulls the + brush against the armature.

A new blower motor installed and Mine is fixed. Napa 6552715. it was $103.20 after buying a Napa shopping bag promotion that gave 20% off the entire purchase.

Help!
 

Reviving the this thread as it most closely describes what I am experiencing. A/C was blowing warm so I had my local Independent correctly evacuate and recharge the system. Worked perfect and blew ICE cold. 2 days later I hop in the car and the display works but no fan and no snowflake. I’m mechanically ok to wrench on things but electronics are my kryptonite. Diagnosing this on about a 5th grade level. Hopefully you guys can help. Checked the fuse(s)? The diagram showed 2? Either way fuses are fine. Reading up on relays now...

So happy
 

Switched out the engine fan relay with the a/c relay AND IT WORKED!!!! So happy right now.

Good thinking...and something I wouldn't have thought of until I was about 8 hours into stabbing around with my multimeter. ;)

Help with diagnosis, please....
 

I've got the same issue where the blower fan doesn't work. I tested the fuses and swapped the relays. No difference.

I got to the fan and tested the voltage on the 2 leads to the fan = 12V. So the fan has to be toast right? So I install a new cheap fan and it doesn't work either. I confirm 12V.

I did a few more measurements. I get 12V at the 2 terminals and a 1000-ohm resistance. I've got no idea about the resistor value. 1K-ohm seems like it's likely in there to prevent the fan from going.

Logic says the new fan is bad too. I don't have a 12V power supply to test the old one. Can there there be something else wrong. Is this too much resistance. The fan should be getting 0.012Amps. Not enough?

Thanks.