Heated seat switch bulb replacement

To diagnose a failure of the fasten safety belts indicator refer to Symptoms - Seat Belts .
Fasten Safety Belt Indicator/Chime Inoperative
Step
Action
Yes
No
Schematic Reference: Seat Belt Schematics
Connector End View Reference: Seat Belt Connector End Views
1
Did you review the Diagnostic Starting Point - Seat Belts?
YES - Go to Step 2
NO - Go to Diagnostic Starting Point - Seat Belts
2
Did you perform the Diagnostic System Check - Instrument Cluster ?
YES - Go to Step 3
NO - Go to Diagnostic System Check - Instrument Cluster
3
Turn ON the ignition, with the engine OFF.
Observe the seat belt indicator illumination during bulb check.
Does the seat belt indicator illuminate during bulb check?
YES - Go to Symptoms - Seat Belts
NO - Go to Step 4
4
With a scan tool, observe the Driver Side Belt Status parameter in the SIR scan tool data list while buckling and unbuckling the driver seat belt.
Does the seat belt parameter change state?
YES - Go to Step 8
NO - Go to Step 5
5
Test the signal circuit of the seat belt switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 11
NO - Go to Step 6
6
Test the ground circuit of the seat belt switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 11
NO - Go to Step 7
7
Test the seat belt switch for an open or high resistance.
Does the seat belt switch have an open or high resistance?
YES - Go to Step 9
NO - Go to Step 10
8
Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.
Did you complete the replacement?
YES - Go to Step 11
--
9
Replace the LF seat belt switch. Refer to Front Seat Belt Buckle Replacement .
Did you complete the replacement?
YES - Go to Step 11
--
10
Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
Did you complete the replacement?
YES - Go to Step 11
--
11
Operate the system in order to verify the repair.
Did you correct the condition?
YES - System OK
NO - Go to Step 2

You have probably burnt up the element as it is a 17 year old seat now. The elements are replaceable, but the labor is pretty spendy. To test it you will need a multimeter to check for continuity across the connectors that go to the seat heating elements and check for voltage at the car side of the connector. If you have 12v to one side of the connector and continuity to ground at the other side, and do not have continuity to the seat side between the connectors, you know it is a bad element.

Heated Seats
This system allows the electrical heating of the front seats on passenger demand.
The components of the system are:

• the seat heating elements located in the seat cushion and backrest.
• the heated seat control switch, located on the seat side trim panel.
• temperature sensors located in the seat cushion heating elements.
• heated seat relay.

Do both front seat heaters not work ? Do you know how to test electrical circuits with voltmeter ?
PINPOINT TEST J: THE HEATED SEAT IS INOPERATIVE Test Step Result / Action to Take J1 CHECK HEATED SEAT SWITCH OPERATION

• Key in ON position.
• Press the heated seat switch on the driver and passenger seats.
• Are both heated seat switch indicators illuminated?

Yes
If both indicators illuminate, Go To Pinpoint Test K . If only one indicator illuminates, GO to J5 .

No
GO to J2 . J2 CHECK THE HEATED SEAT RELAY CIRCUITS

• Key in OFF position.
• Disconnect: Heated Seat Relay C3250 (located under the driver seat).
• Key in ON position.
• Measure the voltage at heated seat relay C3250-86, circuit 1003 (GY/YE), harness side and ground; and between C3250-30, circuit 566 (DG), harness and ground.
  
• Are the voltages greater than 10 volts?

Yes
GO to J3 .

No
REPAIR inoperative 1003 (GY/YE) or 566 (DG) circuit. TEST the system for normal operation. J3 CHECK HEATED SEAT RELAY GROUND CIRCUIT

• Key in OFF position.
• Measure the resistance between heated seat relay C3250-85, circuit 57 (BK), harness side and ground.
  
• Is the resistance less than 5 ohms?

Yes
GO to J4 .

No
REPAIR circuit 57 (BK). TEST the system for normal operation. J4 CHECK THE HEATED SEAT RELAY

• Install a fused jumper lead between heated seat relay 3250-30, circuit 566 (DG), harness side and heated seat relay C3250-87, circuit 1064 (YE/LB), harness side.
  
• Do both heated seat indicators illuminate when pressed?

Yes
INSTALL a new heated seat relay. TEST the system for normal operation.

No
REPAIR circuit 1064 (YE/LB) to switches. TEST the system for normal operation. J5 CHECK INOPERATIVE HEATED SEAT SWITCH INPUT

• Key in OFF position.
• Disconnect: Heated Seat Switch C320 (Driver) or C321 (Passenger) for the inoperative heated seat.
• Key in ON position.
• Measure the voltage between heated seat switch C320-2 (driver) or C321-2 (passenger), circuit 1064 (YE/LB), harness side and ground .
  
• Is the voltage greater than 10 volts?

Yes
GO to J6 .

No
REPAIR circuit 1064 (YE/LB). TEST system for normal operation. J6 CHECK CIRCUIT 57 (BK) FOR AN OPEN

• Measure the resistance between heated seat switch C320-4 (driver) or C321-4 (passenger), circuit 57 (BK), harness side and ground.
  
• Is the resistance less than 5 ohms?

Yes
INSTALL a new heated seat switch. TEST the system for normal operation.

No
REPAIR circuit 57 (BK). TEST the system for normal operation It's not that simple , being a fuse . It's probably the relay or the heating element .
PINPOINT TEST K: SEAT DOES NOT HEAT BUT THE HEATED SEAT INDICATOR ILLUMINATES WHEN PRESSED ? Does it ?
Your best bet would be to take to a qualified repair shop .
Do

Sounds like you have had a lot of fun with this rig
#1 - replace the stereo - that's cheaper than sending yours out for repair.
#2 - Make sure your cooling system is full. You can get an air lock/bubble in the heater core that is really difficult to resolve sometimes. When the cooling system starts to get low on coolant - the heater core is the first to get starved. Physically feel the temperature of the heater hoses at the firewall - they should both be hot - if one is hot and the other not - there is a restriction in the heater core. If neither are hot - your coolant level is probably low. With the engine running you can pinch the upper radiator hose which should force flow through the heater core. Try those things - if you get sufficient heat from other modes - i.e. DEF VENT then your coolant level is not an issue. your controls are your problem - and is this a Auto Temp control system (digital) or manual?
#3 sounds like the ground circuit for Pass side Brake light is not sufficient. Works OK until the park light is turned on. I presume a bulb from the drivers side that worked ok doesn't on the pass side (known good bulb) - the ground circuit needs repair.
#4 the illumination issue - Dash lights/buttons/switches - all those should illuminate together (dimmer controlled)
Radio buttons - refer to #1
Console symbols - wiring connections for the bulbs
Dome lights working ok from rear doors and not the front - probably issues with the front door switches
that's a lot of different things for one car

When you are talking about "indicators" we could assuming that your are refer about signal lights. This work with "flashers" devices.

For 1996 Audi A4 2.8L SFI 6cyl the Flasher is located in front seating area, driver side, under dash, behind dash lower panel, mounted above driver side of steering column.

About generic fuses, open the driver side door. Remove panel on left side of dash. Fuse box is behind panel:

Fuse # / Description / Amps
1 / Heated washer jets / 5
2 / Turn signals flasher unit / 10
3 / Headlight washer, illumination of glove compartment, engine compartment, climate control, automatic transmission, instrument cluster / 5
4 / License plate light / 5
5 / Instrument cluster, seat heating, test connection for cruise control, bulb monitor for auto-check control, Automatic transmission display, switch lighting, mirror switches and actuators, airbag warning light, outside temperature indicator, Climate control / 10
6 / Central locking system / 5
7 / Anti-lock brake system / 10
8 / Vacant
9 / Mirror heating / 10
10 / Vacant
11 / Cruise control (automatic transmission) / 5
12 / On board diagnostic system / 10
13 / Brake lights / 10
14 / Interior lights, reading lights, anti-theft alarm system, vanity mirror / 10
15 / Instrument cluster, power windows, climate control, automatic transmission / 10
16 / Anti-lock brake system, Anti-Slip-Regulation / 5
17 / Heated door locks / 10
18 / High beam right / 10
19 / High beam left / 10
20 / Low beam right / 15
21 / Low beam left / 15
22 / Tail and side marker right / 5
23 / Tail and side marker left / 5
24 / Wiper and washer system / 25
25 / Blower for heating, climate control / 30
26 / Rear window defogger, mirror heating / 30
27 / Rear window wiper / 15
28 / Fuel pump / 15
29 / Engine timing / 20
30 / Sun roof / 20
31 / Tail lights, cruise control, automatic transmission / 15
32 / Engine timing / 20
33 / Cigarette lighter / 15
34 / Engine timing / 15
35 / Trailer receptacle / 30
36 / Fog lights / 15
37 / Radio / 20
38 / Luggage compartment light, central locking system / 15
39 / Emergency flasher / 15
40 / Horn / 25
41 / Anti-lock brake system / 25
42 / Vacant
43 / Vacant
44 / Seat heating / 30

Hope this helps (remember to rate and comme this free answeer).

Possibly.... the only way I know to diagnosis this issue is with an amp meter in the circuit that heats the seats. Compare LH & RH seat heating current draw. If you find the pass seat is NOT drawing the same amount of current, further troublshooting is required. There are TWO heating elements installed in the seats -- seat bottom & seat back, and they are connected in 'SERIES'... so if either element goes/is 'OPEN', then it's component replacement time. There is a thermostat in the heating elements -- it regulates the seat temperature. One must isolate the two elements & check each one individually (seat bottom - checking resistance... and seat back - checking resistance). whichever one (or possibly both) are 'OPEN'. If you find resistance is normal (3 to 5 ohms), then the problem/cause may be in the switch (or its contacts). Using a test light (12 volt bulb), check for power (battery voltage) at the heating element connector to ground (chassis). If the bulb lights up, you know you have power at the switch and is sending it to the heating elements.

The marker lights are removed by depressing the tab (arrow) with a thin bladed tool. Take care not to scratch the paint

1. Disengage the bulb and socket assembly from the lens housing.
   
2. Gently grasp the light bulb and pull it straight out of the socket.
   

To install:

1. Before installing the light bulb into the socket, ensure that all electrical contact surfaces are free of corrosion or dirt.
   
2. Line up the base of the light bulb with the socket, then insert the light bulb into the socket until it is fully seated.
   
3. To ensure that the replacement bulb functions properly, activate the applicable switch to illuminate the bulb which was just replaced. If the replacement light bulb does not illuminate, either it too is faulty or there is a problem in the bulb circuit or switch. Correct as necessary.
   
4. Install the socket and bulb assembly into the lens housing.
   

Not uncommon for the LED in the switch to "burn out". If the seat heater function is normal and the only problem is with the switch illumination a switch is available seperately and can be easily replaced.

check the rail system on the seat. sometimes it pulls the wire out and it doesn't get good enough connection

take the wires off the switches on the pedal and touch together if the lights come on the switch is faulty