Heated Seat Project Question

[Altec103]

I recently purchased a 1999 Toyota Avalon XLS Platinum Edition with the knowledge that the heated seats were not working. However, I am aware that it is an expensive venture ($500 minimum at a Toyota dealer) to fix it with professional help.

This leads me here. I was wondering if there was anything that I could do myself to attempt to fix the problem. Here is what I have done so far...

1) Checked the fuses (None are blown)

As you can see, not an impressive list, but it is mainly because I do not know how to execute on the knowledge I have. My questions are as follows...

1) How do I check to see if electricity is getting the heating element? I mainly am looking for a guide or schematic on how to see if the actual element is broken or if it is a relay to the element. (If the element is not broken, I assume it would be an easy fix)

2) Are there any guides on removing the seat or can I do anything without removing the seat?

3) Does the Avalon have a separate bottom and back heating element with different connectors? I have read a few guides for other cars and something just the heating element for the butt goes out, but if you re-wire the connections one can have it so just the lumbar (back) heating goes on.


Thanks for the help. I am not 100% set on actual making the repairs, but I want to troubleshoot everything so I can at least pinpoint the failure in the system.

[fourwheeler]

I would use either a volt/ohm meter, or a continuity checker and start with the switches. Check to make sure power is getting to the switches, check to see if the switches work. I think you can check for continuity through the heating element, open circuit would mean the element would need to be replaced (broken wire) and resistance (unsure how much) would at least indicate a continuous circuit. You can check youtube for instructions on using a continuity checker or just get a cheap volt meter.

[BMR]

Yeah, what fourwheeler said above.

The heater resistance will probably be quite low. Power = V^2/R. Rearranging terms; R = V^2/Power. Looking at the aftermarket ones, wattage is typically 50 or so. Assuming 12 volts, resistance calculates out to be 2.88 ohms. So if you see anything over 4 or 5 ohms, something's probably wrong.