Heated Seat Solution
#107
OK, FWIW let me throw in my $.02. I took delivery of a G35S 6MT 10 days ago. After reading this thread and the tech bulletin I did some checking.
First, the bulletin applies only to cars manufactured before mid-December 2006, and below a certain serial number. Mine was manufactured in January 07 and is above the serial number; so presumably the seats should function correctly.
Both the driver's and passenger's seats definitely get warm in the "high" position. It seems like the seat bottom gets warmer than the back, but then I tried it without my jacket on and sure enough the back got warm too (but seemingly not as much as the bottom). They seem to sustain heat in the low position, too. However, the seats are slow to heat up, nothing like the seats in the "brand X" 335i I test drove.
Out of curiosity (I'm an engineer, I can't help it....) I pulled the seat heater fuze and measured the heater current draw, as shown below. Also included is the wattage, assuming a 12 volt supply. Yes, I verified that there was no current draw when neither seat was on, just in case there was some other load on the fuze.
Driver side
Low 1.8 amp 21 watts
High 5.4 amp 65 watts
Passenger's side
Low 1.3 amp 15 watts
High 4.3 amp 52 watts
It's curious that the passenger heaters deliver less than the driver side heaters. But note that in both cases the low setting is about 1/3 of the high setting. Also, the differing currents and my "seat of the pants" (literally) lead me to believe that the high/low heating is working correctly.
It would be interesting to know similar current consumption figures for a pre-fix car that is not working correctly. I would expect there to be a far smaller difference (if any) in the current between high and low settings.
First, the bulletin applies only to cars manufactured before mid-December 2006, and below a certain serial number. Mine was manufactured in January 07 and is above the serial number; so presumably the seats should function correctly.
Both the driver's and passenger's seats definitely get warm in the "high" position. It seems like the seat bottom gets warmer than the back, but then I tried it without my jacket on and sure enough the back got warm too (but seemingly not as much as the bottom). They seem to sustain heat in the low position, too. However, the seats are slow to heat up, nothing like the seats in the "brand X" 335i I test drove.
Out of curiosity (I'm an engineer, I can't help it....) I pulled the seat heater fuze and measured the heater current draw, as shown below. Also included is the wattage, assuming a 12 volt supply. Yes, I verified that there was no current draw when neither seat was on, just in case there was some other load on the fuze.
Driver side
Low 1.8 amp 21 watts
High 5.4 amp 65 watts
Passenger's side
Low 1.3 amp 15 watts
High 4.3 amp 52 watts
It's curious that the passenger heaters deliver less than the driver side heaters. But note that in both cases the low setting is about 1/3 of the high setting. Also, the differing currents and my "seat of the pants" (literally) lead me to believe that the high/low heating is working correctly.
It would be interesting to know similar current consumption figures for a pre-fix car that is not working correctly. I would expect there to be a far smaller difference (if any) in the current between high and low settings.
#109
Originally Posted by PiDD
How do you check the current draw? I have a voltmeter and I have the heated seat problem. Just need the know how.
1. Retrieve the fuze puller from the fuze panel on the left panel under the dash on the driver's side
2. Remove the battery cover panel and the fuze cover under the battery cover. (see owner's manual)
3. Using the fuze puller, remove the 15 amp (blue) fuze for the heated seats. Fuze locations are shown on the diagram on the fuze cover.
4. Press the "start" button twice to turn on everything (but don't step on clutch/brake, so car does not actually start). Instrument lights and display should be on or no power is being supplied to seat heaters.
5. Turn on driver's seat heat to "high". Yellow light will not come on because fuze is pulled.
6. Using the pointed probes, carefully connect to the two sockets on the fuze block that the fuze would normally contact. To get a good reading, make sure the two probes do not touch each other (This is a bit tricky). If they do happen to touch no harm occurs; the meter is in effect replacing the fuze so we can get a current reading. Oh, and note the reading. If the electronic meter indicates "minus" amps, don't worry, it's just the polarity you chose.
7. Repeat steps 5 and 6 for driver's side low heat. Then turn off driver's side heat and repeat steps 5 and 6 (twice) for the high and low settings on the passenger seat.
8. When you're done, press the start button once more to turn everything off, replace the fuze and the two covers.
I don't mean any offense, but if you are inexperienced and/or uncomfortable with electronic measurements using appropriate meters, I suggest you recruit a friend who understands how to use the meter and what is being measured.
BTW there is no danger of shock, the car system is only about 13 volts. However, you should remove jewelry (e.g., watches, rings, neck chains) when working around any auto electrical system as the battery can deliver enough current to melt a ring or watch band.
If it would help, I can take/post some pictures tomorrow.
#110
I just talked to my dealer here in Denver. He had no idea about the bulletin and called back saying he couldn't find it. I gave him the URL for the website and he called back saying he has ordered the parts and they'll fix it next week. I shouldn't reallly know more than the dealer, should I???
#113
Originally Posted by GumboChief
bkrider, I have a G35x built in January, and the passenger seat gets MUCH hotter than the driver's
The current measurements I described above could be revealing, especially if they show the passenger seat drawing significantly more current than the driver's seat. My G35 is a Sport, it's possible that even when fuctioning correctly the non-sport seats may draw different current. But I would still expect the measurements to be in the same range, and have about the same 3:1 ratio between high and low settings.
Good Luck.
#114
Bringing this thread back from the dead just in time for Summer, I've just had the heated seats "fixed" today. While the drivers seat seems to work in both high and low settings the passenger seat is a tricky one to test. I put the seat on high while I drove home (about an hour) and tested it when I arrived to find it cold. Before pulling everything apart I figured I'd measure the current through the circuit to confirm something was happening. On the driver side, high draws about 5 amps and slowly drops to 2 over a period of about 15 mins. Low starts at about 1.25 amps and drops very slowly to about 1.15 amps over the same time period. Fair enough. The passenger side starts around 4.7 amps on high and gets hot noticeably quicker than the drivers side. Over 5-10 mins it drops to about 4.2 amps and then turns off. No current. The lamp is still lit on the switch but the current drops to zero and the seat starts to cool down. I let it cool for about 20 mins expecting the heater to cycle but nothing happens. As soon as the switch is set to low, the seat starts getting warm again and draws about 1.3 amps dropping very slightly. Looking at the diagram in the service manual there seem to be two switches/sensors. Can anyone confirm this operation or let me know how the seats are supposed to work before I start pulling stuff apart?
#115
#116
Originally Posted by NewMexicoG
Bringing this thread back from the dead just in time for Summer, I've just had the heated seats "fixed" today. While the drivers seat seems to work in both high and low settings the passenger seat is a tricky one to test. I put the seat on high while I drove home (about an hour) and tested it when I arrived to find it cold. Before pulling everything apart I figured I'd measure the current through the circuit to confirm something was happening. On the driver side, high draws about 5 amps and slowly drops to 2 over a period of about 15 mins. Low starts at about 1.25 amps and drops very slowly to about 1.15 amps over the same time period. Fair enough. The passenger side starts around 4.7 amps on high and gets hot noticeably quicker than the drivers side. Over 5-10 mins it drops to about 4.2 amps and then turns off. No current. The lamp is still lit on the switch but the current drops to zero and the seat starts to cool down. I let it cool for about 20 mins expecting the heater to cycle but nothing happens. As soon as the switch is set to low, the seat starts getting warm again and draws about 1.3 amps dropping very slightly. Looking at the diagram in the service manual there seem to be two switches/sensors. Can anyone confirm this operation or let me know how the seats are supposed to work before I start pulling stuff apart?
#117
Email from Dealer
Originally Posted by douglas555
I had mine "fixed" also and get the exact same results. Drivers side seems fine but passenger side doesn't seem to heat up much at all. When my wife was riding in it she felt it cycled - hot and not. Haven't talked to the dealer yet, but I'm taking it in next week to have the sunroof finisher fixed, as well as hopefully the voice tags and roof noise.
Me: Also, the fix to the heated seats didn't seem to make much difference in the heat (that may be just the way that they work).
Service: As far as the heated seat that is they way they are going to be, there was a difference in temp when the repair was completed of about 5 to 10 degrees.
#118
Before I brought in my car for service, I told my dealer that I wanted the heated seats fixed. I even gave them the bulletin number, and I told them they should order the parts to ensure that they'll be there for my appointment 2 weeks later. I brought my car there, and when I picked it up, they said they didn't have all the parts. This was around end of April. They said the parts were in national back order. Either that's the case, or they didn't order the parts correctly like I requested 2 weeks earlier. Anyway, with the heated seats not yet fixed, when I turn on the heat, it feels warm, unlike before. But, it's now mid-May, so they heat up a lot better than in the middle of winter. I supposse the true test for the fix is to see how it behaves (e.g. feels) in the middle of winter. I wonder if I should just wait until, say, next December to request for the fix. By then, they should have ironed things out and the dealer would have more experience fixing heated seats (unless everyone else like me decides to wait until next winter).
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