Mattias78 Posted August 7, 2014 Report Posted August 7, 2014 Hi! When i turn on my heater fan, the switch under the dash starts smoking:( Has anyone done a rebuild on one of these? Or can i find a replacement (new?) i have looked on eBay an found nothing! Thanks! Quote
linus6948 Posted August 7, 2014 Report Posted August 7, 2014 There is also the possibility that the fan motor itself has a problem and the switch is heating up as a result of the possible resistance created by the bad motor. This is an electrician`s angle on a smoking switch, we would always look at the motor first. 2 Quote
Don Coatney Posted August 7, 2014 Report Posted August 7, 2014 What might cause this? Is perhaps the heater fan blade dirty? Is the heater motor in need of lubrication? Are the circuit grounds up to snuff? Is the wiring broken down causing a higher than normal amp draw? I suggest you investigate a bit further and find the source of this issue. Quote
linus6948 Posted August 7, 2014 Report Posted August 7, 2014 Here is a Switch http://www.ebay.com/itm/1946-1947-1948-plymouth-dodge-desoto-chrysler-NOS-heater-switch-/121375106418?pt=Vintage_Car_Truck_Parts_Accessories&hash=item1c42852572&vxp=mtr Quote
Mattias78 Posted August 7, 2014 Author Report Posted August 7, 2014 I had the motor out and did some re-wireing on it, and as far as a can tell the fan moves easily. I did run it straight of the battery! Ran fine. I did however notice that the rpm went up and down on the motor! when i got it back in the car! Linus, i did see that switch! mine looks a bit different, mayby that dosen't matter! /Mattias Quote
james curl Posted August 7, 2014 Report Posted August 7, 2014 I assume you are still running 6 volt system, because if you are running 12 volts the resister coils on the switch that drops the voltage for the two lower speeds are getting too hot. Quote
Mattias78 Posted August 7, 2014 Author Report Posted August 7, 2014 Yes! Still 6 volt! Forgot to write that the 2 first speeds isn't working! Only the third! This problem should be the switch, right? Quote
greg g Posted August 7, 2014 Report Posted August 7, 2014 (edited) the switch controls voltage going to the fan, 6V= high speed, lower speeds are lower voltage maybe 4 and 3, voltage is dropped by the switch through resistance prior to the motor. Resistance = heat, too much heat = smoke, to much smoke = don't work no more. high turning friction will also cause higher than normal resistance at the motor and a poor ground will add even more. So start with the ground and make sure it good, then check the fan w/o power to see if it spins freely. If it doesn't clean and lubricate it. Then check the wire tothe motor make sure its in good shape with good connections. then check the power into the switch to make sure its getting the full 6 V from wherever the supply comes from. You can jump the fan motor direct to power,it should turn at full speed and the connections of the jumper wire should stay relatively cool to touch. If they get hot then the motor might be dragging or dirty. Edited August 7, 2014 by greg g Quote
Mattias78 Posted August 7, 2014 Author Report Posted August 7, 2014 Will check my wires again tomorrow! Thing i'm going to disconnect the switch untill i have worked this out properly! Don't want start a fire! Thanks! 1 Quote
meadowbrook Posted August 9, 2014 Report Posted August 9, 2014 It has been proven that all electrical devices are powered primarily by smoke, once it leaves the device, it no longer works. Speaking of this, my 50 has a 2 speed switch and on low, it does get hot, and it is from the one big resistor attached to it. No smoke, but if you reach beneath it and touch the resistor, you will get a surprise. 1 Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.