The fan will only work on the highest setting after smoke was emmitted from the heating ports inside the car, could you inform us on possible problem and location of replacement part.
My car is a 1994...
The fan speed resistor pack has burnt out, a very common fault on a huge number of makes and models. Top fan speed works as that's the only switch setting where the resistors aren't used.
I'm on the wrong side of the Atlantic to be familiar with your model, but on most cars the resistor pack is on top of the fan motor intake box behind the glove-box (which may need to be removed for access). Usually it's in a similar area to the cabin air filter, and looks like a small plate with a four wire (for a four speed fan), single electrical multi-plug going to it and typically held in place with a couple of screws.
The resistors are usually just very primitive coils of resistive wire, and if there's not enough airflow over them then they overheat and burn out. There's always one less resistor than the number of fan speeds, so for a typical four speed fan there are usually three resistors. The resistors work in series, so on a four speed fan, the slowest speed passes the fan motor voltage through all three resistors, the second slowest uses just two resistors, third uses one and top speed (for a four speed) bypasses them all. Each resistor causes an approximate drop of 3 volts and dissipates around 4.5 Watts.
The fix is to replace the resistor pack, but if you have soldering skills then you can replace the resistors with something better for less money. I typically use wirewound resistors with a minimum rating of 10W, and ideally rated at 1.5 Ohms but for the last few repairs have used 1 Ohm examples instead as they're all I could easily get. the end result may have slightly different fan speeds to before but will work.
When you fix the fault, make sure that the airflow is unimpeded. Clean out as much debris as you can and replace the cabin filter. It's usually a choked cabin filter which causes the fault to start with.
If you have to get the job done professionally then it's normally a quick repair (under half an hour) on most models, but if there's more dismantling needed to get at the work-site then it will cost more. In the UK a resistor pack typically costs up to around £30, so total repair costs will be about £70. When I fix this myself with my soldering iron the repair takes around 45 minutes and costs me about £10. A replacement resistor pack from a wrecking yard typically costs £10-£15 if you don't like soldering.
Jul 06, 2011 |
Lincoln Town Car Cars & Trucks