What would cause the fan to work only on the highest setting?
pull the knob off you temp switch and put it on the blower control and see if it works..i had the same problem and it was a bad knob Possible switch, resistor, relay or blower motor. Possible heater blower motor resistor. Most manufacturers let the fan override the resistor when high is selected for safety reasons Most often manufacturers use a resistor block containing bare wound wire resistors to vary the fan speed. The high speed settings simply puts the full 12 volts to the fan motor (no resistor involved). The problem is that - for whatever reason - they also include a thermal protection device that is in line with the resistors that are used to reduce fan speed. These little diode looking devices are located usually in the middle of the resistor group on the resistor block. When this thermal sensor fails, either thru overheating, or age, or design, then the current can't flow through the resistors to provide lower fan speeds - only the high speed position functions. In my personal humble opinion, I suspect that these thermal protection devices are designed to not to last too long!! My assumption is that their purpose is to prevent the resistors from overheating if for some reason the air flow thru the air duct is blocked (leaves, snow, what ever). I've had this happen on newer Fords and Chrysler vans. So now when there is a failure I clip the thermal device out of the block and solder in a small piece of thin copper wire which restores all fan functions. Is this practice dangerous. Yes, IF you allow flamable material to build up in the air duct (not sure how this could happen - but anything is possible).
How do you fix an air conditioner that only works on the highest setting in your 1997 Nissan Pathfiner?
Why will only the high fan work on a 2005 Chevy trailblazer AC Why does only the highest setting on my ac fan on the 2005 Chevy trailblazer?
There is a fan motor resistor board located under the dash on top of the plastic duct housing on the passenger side of the vehicle. It is behind the glove box. Removing the glove box will help you to get to the resistor. The power to the fan motor uses various resistances on that board to get your lower fan speeds, but on the highest setting it bypasses the resistors since they are not needed…
Will setting a Lead Acid Car Battery directly on the ground without an Insulator like a piece of wood cause it to drain voltage?
No. Setting any kind of battery on the ground has no effect on its electrical characteristics. Electrical energy is drawn from a battery only by things that are connected between the battery's positive and negative terminals. Think of this, new batteries are kept on metal shelves. Steel is a better conductor than concrete. So if you could "drain" a battery by setting it on something, a steel shelf would be more efficient.
Your 2005 Grand Cherokee's AC suddenly only works on highest fan setting What if the lower settings do not activate fan nor does compressor light illuminate Only works on high.any ideas?
What would cause the wipers on a 92 grand marquis to only work when set to the highest level and then shut off?
What would cause the Air Conditioning to only blow out the defrost vents in a 1999 Ford F-250 Diesel?
Some ford truck hvac systems will default to the defrost setting if the is a problem with the electrical or vaccum parts of the system. I encountered a ford truck that had a mouse living under the hood and chewed through the vacuum hoses and would only blow on defrost.Do a good visual check including electrical,such as fuses etc...
As you did not say which vehicle this can only be a general answer Unlikely that a faulty coil would cause an engine to knock. Very possible it would cause bucking, if the coil is failing there would be a lack of spark. This would cause bucking/missfire, which may cause the engine to shake on it's mountings possibly causing a knock from contact with the vehicle frame.
What would cause all power windows to only work once in awhile and defroster to go out on 2004 dodge ram?
It is highly unlikely that epilepsy would cause a cough of any kind. Epilepsy affects the brain, and although that in turn causes effects in other parts of the body, it would not cause a cough. The effects of epilepsy would only last during a seizure, whereas a chronic cough would be something that would be continuous. The cause of a problem cough would lie elsewhere.