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So far, so good... Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Thu, 21 Dec 2000 10:01:01
In Reply to: Ari, I tried your suggestions and..., DET, Wed, 20 Dec 2000 23:11:04 Members do not see ads below this line. - Help Keep This Site Online - Signup |
So far it appears that the seat heater is operating properly. That 'click' was the relay in the controller opening, taking power from the seat heater element. The controller obviously believes that the seat was up to '3' temperature. You don't feel the seat is hot enough - this isn't a fault, just a difference of opinion.
Your note states that the seat heating element (yellow/white to black) measured around 160 ohms. Are you sure? The element should be on the order of 2-4 ohms.
Remember, the seat doesn't get that hot in open air. Stick your butt & back on it, and it will feel a lot warmer. I turn my seat heater on to '3' and go off to scrape the windows - when I get into the car, the seat doesn't feel warm until I've sat for a bit.
However, the seat may not be getting hot enough for you, and that's all that matters. If sitting in the seat, after 5 minutes or so you don't feel the seat is warm enough, you'll want to increase the heat. The seats don't come up to temperature in seconds - it takes a while to heat up the cushions and the surrounding material. You could futz with the seat controller, but there's a different way-
I'm pretty sure the temperature sensor is a Negative Temperature Coefficient variable resistor. What that means is the resistance decreases as temperature goes up. Don't worry about the voltage on the sensor (4-6 volts) - that's just the controller's way of measuring the sensor's resistance. What you want to do is fool the controller into switching off at a higher temperature. To do this, all you need to do is add some resistance between the sensor and the controller. Basically, find the Blue/white wire which comes from the sensor, cut it, and add some resistance. This will fool the controller into thinking the seat is colder than it really is, and it will keep the relay closed longer - i.e., a hotter seat.
How much resistance to add? Good question. The sensor should be at about 1000 ohms at room temp. I don't know the type of sensor, but based on experience, I'd say about 200-300 ohms should be worth about 10 degrees C.
Try this - go to Radio Shack, and buy a small 500 ohm potentiometer. Wire it in series with the sensor (break the blue/white wire). Set the potentiometer at about half and see if you find the seats get hotter. Play with the setting until you find one you like - then pull out the potentiometer, measure its resistance, and replace it with a standard resistor of close to the same value. Or just tape the potentiometer's shaft up so it won't turn and leave it be. Now you can decide how hot '3' is.
Good luck!
, Wed, 20 Dec 2000 15:59:06, Thu, 21 Dec 2000 10:01:01 <-- Viewing This Message, Thu, 21 Dec 2000 13:25:18, Fri, 22 Dec 2000 08:55:43
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