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Just to be sure, this black wire that you labeled "1" goes to C918 (Connector B) pin #1, which turns to brown, and goes to the seat back?
What does black wire connects to on the male side of connector on this picture?
In your post #33 you are using correct connector and pin numbers, but wrong colors. (take a look at stuff in blue [representing "Connector A"] in post #35)
Looking at female Connector A (one that is unlabeled on my diagrams):
- pin 1 should be green yellow
- pin 2 should be white blue
- pin 3 should be black
(just like you wrote)
Pin 2 to pin 3 is cushion resistance.
Pin 3 to pin 1 is seat back resistance.
Pin 1 to pin 2 is total of cushion and seat.
Your cushion resistance is quite high compared to back seat.
26 ohm means at 12V you have ~0.5A running through the heater, meaning like 6W of power. I don't think that's enough.
In comparison you have 5 ohms at the seat back, meaning at 12V you have 2.4A which gives ~30W.
I bet that this resistance goes higher as you pass some current through it and that's why cushion doesn't work.
At high, seat back will see 12V, and will get hot. Bottom will also see 12V but high resistance means low power means low heat. At low, cushion's high resistance prevents the whole seat from warming up.
If I get bored tomorrow I might measure my seat.
Your diagram that you posted might be incorrect. In Post #16, Pin 1 on the A connector is black. Pin A2 is blue/white, and Pin A3 is green/yellow.
On Connector A, which, as I said previously, had three wires (black, white/blue, and green/yellow), the black wire is connected to the black wire on the female side of Connector A.
As for the colors, this is what I have in my car: There are three wires coming INTO Connector A: Black connected to black ( Pin A1) Red/Gray connected to blue/white wire (Pin A2) Gray connected to green/yellow wire (Pin A3)
Please do measure your seat resistance and voltage. I measured 10.9V going into the cushion on LO and HIGH.
The service manual, at least that I know of, does not say to test resistance, only continuity (which is the same thing using a DMM). Technically my seat cushion is getting continuity, but the resistance is still too high, which would, as you said, make the wattage low. I wonder... Let me know what ohm reading you get between Pins A1, A2, and A3. It bugs me that the seat heater element is $186, not including shipping, and that the thermostat and breaker are not separate parts.
#16 photo of service manual - they are numbering the pins looking at the back of female connector.
Info that I pulled from Alldata, including different version of the OEM manual, numbers female terminals looking at the front of the connector.
That is what identifix and alldata consider a OEM circuit diagram, and that is what I most often work with.
That's the connector view, looking at the front, with wire colors for male and female.
Seems like both sources are right - they are just different. It's important to mention which "system" is being used when naming stuff.
Because post #16 service manual was first, I should have kept numbering and naming present there. However I couldn't find wire color data and connector info in service manual pages that we have at this forum, and that's why I went to Alldata.
10.9V that you measured is your key on engine off battery voltage? Kinda low.
That's the correct diagram as far as I know. I have no idea why all of the sources draw those diagrams wrong but at least procedure for checking the circuits in the service manual is correct. Guess Acura must messed up. I took apart the wiring between female connector A and male connector B (918) to make sure the wires go where I drawn them.
I went over this diagram three times, but if there is still something wrong let me know and I will fix it.
It is weird to see 11.5V at the heaters connector when battery is at 13.5, but that must be due to collective resistance of switches and wires going from the battery to the heaters.
At HIGH, pin #2 (white blue) is grounded by the switch, yet there is still 1V of difference between body ground and ground through the switch.
My seat works so I'm assuming all measurements as "Known good". Brand new heaters might be different, but 1 or 2 ohm of difference doesn't really matter. If you measure 20 ohms then something is wrong.
Resistance for Connector A is measured with Connector A disconnected, Connector B connected.
Resistance for Connector B is measured with Connector B disconnected.
That should be all. Again, making this diagram is stupidly overcomplicated task compared to what a simple circuit (of basically two resistors either run in series or parallel) it is.
Thank you for measuring the voltage. If your seat heaters work, then the voltage must be right. Even though I'm getting continuity between pins A2 and A3, it should be much lower for the bottom seat heater. It bugs me, but not enough to spend $186 on a heating seat element. Then again, I spent $320 4 months ago to get a new silver interior dash trim piece by the radio.
This was on my AV6, but should be similar on the TL. My seat bottom was not warming up, also not the seat back, I was actually getting continuity for seat back and seat bottom pins. But I did not see the issue until I tore open the seat back. The wire toward the top left shoulder area inside the seams had burned, most likely from me getting out of the car "elbowing" on the seat back to prop myself out frequently. The old seat back heating element was nasty with peeling material so I bought a new element, it's well worth it by the way. The seat bottom started working also, the burned wire in the seat back element was causing periodic shorts to the entire circuit including the seat bottom. If you don't want to spend that type of money then use a soldering gun and a new small section of wire to repair the break and it should work. You will need a set of hog ring pliers + a bunch of hog rings to attach the leather back.
11-21-2020, 11:12 PM
Let me know what ohm reading you get between Pins A1, A2, and A3. It bugs me that the seat heater element is $186, not including shipping, and that the thermostat and breaker are not separate parts.
