the fan that is supposed to blow air for the defroster, the heater, the AC will just stop working intermitently. No pattern to when (hot cold wet dry turning going straight etc) it chooses to not work. When it works, i have the correct temperature air at the correct variable speed for whatever setting I put it. The local shops and dealership won’t do anything until they see it not work and, of course, I haven’t been able to show them broken. I’m thinking electrical short but don’t know which pieces to start replacing to find the short. Suggestions?
First, you need to use/understand the correct terms.
It’s not a “short.” A short is when a circuit is completed in a way that it shouldn’t be. A short causes excess current to be drawn and fuses to be blown. It could also start a fire.
What you have is an intermittent “open.” That’s a loose connection somewhere that opens up the circuit and prevents (in this case) the blower motor from getting current.
Intermittent problems are very hard to diagnose. If it won’t fail while they are looking at it, then anything they did would just be guessing and throwing parts at it. I assume that it is not in the failed state very often. You may have to wait till it fails completely or at least frequently before you can get this fixed.
Your car should be under warranty. You don’t want to loose that warranty before you get this problem resolved. Lemon Laws protect you from having a warranty from running out, before the problem is resolved.
If I choose not to do that so I can see out the window(defroster needed) and not freeze in the coming mid-west winter(ended up with fronstnip on two toes driving home last year), do you have a suggestion of an order of least expensive parts to start changing to eliminate the intermittent open?
Unfortunately, it is now out of warranty(mileage- very long commute) and I still haven’t been able to show the mechanic at the dealership “broken” so they claim they are not responsible.
Do you have electronic climate control?
Blower speed control.
Electronic climate control head.
Be warned that there is a good chance that it is a $5 connector somewhere instead.
In fact, you should start by disconnecting and reconnecting all connectors involved.
(Which ones are involved? You’ll need the factory wiring diagrams for that.)