Steering Wheel Heat Mod?

Hi there:

Everyone knows about the steering wheel heater turning on until it burns, then thermally shutting off for a few minutes and starting over. But today I was thinking about how easy it would be to provide a mod that would provide three "levels" of heating, low, med and high without shutting off. The idea came from other posters mentioning how they manually cycle the switch to keep it warm. I noticed that with different time cycles (x min on, y min off) you can easily maintain different temperatures. And this would be really easy with a digital micro-controller.

Only thing is I do not have any idea how the switch is wired. I am assuming it must be "logic control" not a direct wire for the switch and the LED. It would be very easy to intercept and put in a control, including visual feedback. I was thinking of having a quick on/off hit be a "medium" setting, while holding for longer period allowing the setting to be changed.

Thoughts? Can anyone provide any info on the wiring?

Thanks.

Interesting.

It can be done obviously, although it may take some experimentation to get the timing correct.

Unless you want to build a circuit from scratch, the easiest way would be to use an Arduino board, and interrupt the on/off signal right from the switch.

Switch on, Arduino system on.

That way you would not have to dig into the guts of how the system works.

If you were clever, you could hook up a thermocouple (temp sensor) to the Arduino as an input, and program the system to modify the on/off times based on ambient temperature.

Good luck

KillaWhat said:

Interesting.

It can be done obviously, although it may take some experimentation to get the timing correct.

Unless you want to build a circuit from scratch, the easiest way would be to use an Arduino board, and interrupt the on/off signal right from the switch.

Switch on, Arduino system on.

That way you would not have to dig into the guts of how the system works.

If you were clever, you could hook up a thermocouple (temp sensor) to the Arduino as an input, and program the system to modify the on/off times based on ambient temperature.

Good luck

Click to expand...

Thanks if I can get the info I would preferring making a small board from a PSOC type controller, just to minimize the board footprint. Was thinking of temperature sensor but I am trying to prevent visible wiring. A small board should fit behind the switch itself.

Been playing with timing manually, a 30 second on/off cycle mahesh nice medium heat...

My plan, if I ever get around to it, would be to put a 12vdc to 9vdc converter on the line feeding the steering wheel. Does anyone know what the steering wheel actually pulls amp wise? I would think it would get warm enough and not hit the hi temp limit and shut off. I would much rather have a warm wheel all the time than a hot one once in a while.

BrockWI said:

My plan, if I ever get around to it, would be to put a 12vdc to 9vdc converter on the line feeding the steering wheel. Does anyone know what the steering wheel actually pulls amp wise? I would think it would get warm enough and not hit the hi temp limit and shut off. I would much rather have a warm wheel all the time than a hot one once in a while.

Click to expand...

Well what is interesting is that even when I cycle the wheel heat on/off manually and not allow for temp to get to high it STILL shuts off. I wonder if its just a timer?

There is also a timer that shuts off the steering wheel heater after 30 minutes. The timer circuit pulls in a relay, which connects the +12 volts to a thermostat in the steering wheel.



I think that perhaps the easiest way to reduce the heating power is a simple pulse-width modulator circuit inline with the ground (-) leg of the heating element: