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Re: I always set it to 3, and I removed the temp sensor! Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Wed, 30 Oct 2002 13:35:49
In Reply to: I always set it to 3, and I removed the temp sensor!, Jeff Cunningham, Wed, 30 Oct 2002 12:59:36 Members do not see ads below this line. - Help Keep This Site Online - Signup |
I don't remember the circuit well enough to know what an open temp sensor will do. It should default to either full heat all the time or no heat ever. If you are getting heat, well that probably is about the best.
If you wanted to be absolutely sure you're getting every last Watt, grab a volt meter and slide the seat forward. With the car on, the meter set to Volts, put the negative on a good ground, and check both the high side (yellow, from memory, but don't quote me on this) and the ground to/from the heating element. You should see pretty close to battery voltage on the high side. If you've got more than a few hundred millivolts (0.2 to 0.3 volts) less than the battery voltage, then there is a drop in the system. This could be the relay in the dash controller, contacts on the back of the controller, or wiring to/from the controller.
The return (black) line from the heater should be no more than a few tens of millivolts above ground - basically, zero volts. If not, clean up those ground points.
From my first post, one way to get more heat is to apply more volts. If you've got voltage drops on the way to or the way out of the heater, you're stealing voltage. If you have some bad contacts you could be losing 1 or 2 volts in a bad ground. That may not sound like a lot, but it's WATTs that warm your buns, and watts increase with the square of voltage (power = voltage squared divided by resistance).
So 13.5 volts through a nominal 3 ohm heater is 60.75 watts. Lose a volt down to 12.5, and that's only 52 watts - a 15% drop. So make sure you're getting every last volt you deserve.
Quite frankly, I find the best part of the seat heater to be the back, not the seat bottom. If you feel the same, one possibility would be to wire out part of the seat cushion heater - basically, find a section that you don't mind running a little cooler, and wire across it with some 16 gauge wire. You don't want to get too out of hand, because you're increasing the current, and at some point you'll exceed the current rating of some component. But that would heat up the seats faster.
I *guess* you could put some heat reflective material below the heating element, below the foam. That would drive more of the heat up towards you, and less to heat up the underside of the seat. I would just be careful to electrically insulate it from the heating element wire. Yes, the wire is insulated, but that insulation can fail. Of course, avoid anything that will insulate you from the heater, like extra seat covers.
posted by 192.249....
, Wed, 30 Oct 2002 12:41:10, Wed, 30 Oct 2002 13:35:49 <-- Viewing This Message
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