aradileepan
New member
Hi,
I'm having trouble with the heaters in the seats from a Discovery 2. The seats are installed in a 1988 Landcruiser. The motors work but the heaters don't.
A single 30 amp fused relay powers the seat adjusters. The relay is triggered with the ignition in the ACC position (first click). Both seats' heaters are also powered by a single 30 amp fused relay. That power is spliced into pig tails from the factory seat control/heater switch harnesses.
Each heater switch (also stock that I took from the donor) has four wires: black, red, green with white stripe, and blue with gray stripe (left side) and blue with pink stripe (right side). I ran the power from the fused relay to the green with white stripe, then connected each blue wire with its respective seat. I grounded the black and red wires. I was told that the red wire is to illuminate the switch with the headlights, but I haven't done that so I just grounded them (could this be the problem? Are the reds supposed to be connected somewhere?)
When I press the heater switch, the amber light comes on to tell me it's powered, but I get no heat. I've traced power all the way down to the heater module and beyond back to the connection to the heater elements.
This picture shows that connection to the elements: pink with white stripe, light green, black, and pink, which is also shown here in the diagram:
When the switch is activated, here are the readings I got across the terminals at this connection (measured from each colored wire to the black ground):
1. pink with white stripe to black: 0
2. light green to black: 1.59v and a click at the module
3. pink to black: 12.5v but no click
Below is what the Land Rover Electrical Library explains:
Power is supplied to the electronics within the LR or RH seat heat module by the feed from the LF or RH seat heater switch. This allows the feed to pass through the module and is connected to the LH or RH seat cushion heater on a PINK wire.
The LH or RH seat squab heater is connected in series from the LH or RH seat cushion heater on a PINK?WHITE wire. The LH and RH seat squab heaters are connected to earth header C0708 on BLACK wires via splice joint 1.
The earth from the LH or RH seat heat module is connected on a LIGHTGREEN wire to a temperature variable resistor contained within each of the LH and RH seat cushion heaters. As the temperature of the seat cushion heater increases, the resistance of the resistor changes. This is sensed by the seat heat module which varies the power supplied to the LH and RH seat cushion heaters, raising or lowering their temperature accordingly.
The resistors are connected to the LH and RH seat heat module on BLACK wires from the LH and RH seat heat modules to earth header C0708 on BLACK wires via splice joint 1.
So, if I'm getting 1.59v across light green and black, does that mean the resistor is working? I'm getting 12.5v at the pink, which is the powered wire, so I think I'm good on that.
Should I connect the red wire at the switch to something? Any other ideas to test?
I'd appreciate any help.
Thank yo
I'm having trouble with the heaters in the seats from a Discovery 2. The seats are installed in a 1988 Landcruiser. The motors work but the heaters don't.
A single 30 amp fused relay powers the seat adjusters. The relay is triggered with the ignition in the ACC position (first click). Both seats' heaters are also powered by a single 30 amp fused relay. That power is spliced into pig tails from the factory seat control/heater switch harnesses.
Each heater switch (also stock that I took from the donor) has four wires: black, red, green with white stripe, and blue with gray stripe (left side) and blue with pink stripe (right side). I ran the power from the fused relay to the green with white stripe, then connected each blue wire with its respective seat. I grounded the black and red wires. I was told that the red wire is to illuminate the switch with the headlights, but I haven't done that so I just grounded them (could this be the problem? Are the reds supposed to be connected somewhere?)
When I press the heater switch, the amber light comes on to tell me it's powered, but I get no heat. I've traced power all the way down to the heater module and beyond back to the connection to the heater elements.
This picture shows that connection to the elements: pink with white stripe, light green, black, and pink, which is also shown here in the diagram:
When the switch is activated, here are the readings I got across the terminals at this connection (measured from each colored wire to the black ground):
1. pink with white stripe to black: 0
2. light green to black: 1.59v and a click at the module
3. pink to black: 12.5v but no click
Below is what the Land Rover Electrical Library explains:
Power is supplied to the electronics within the LR or RH seat heat module by the feed from the LF or RH seat heater switch. This allows the feed to pass through the module and is connected to the LH or RH seat cushion heater on a PINK wire.
The LH or RH seat squab heater is connected in series from the LH or RH seat cushion heater on a PINK?WHITE wire. The LH and RH seat squab heaters are connected to earth header C0708 on BLACK wires via splice joint 1.
The earth from the LH or RH seat heat module is connected on a LIGHTGREEN wire to a temperature variable resistor contained within each of the LH and RH seat cushion heaters. As the temperature of the seat cushion heater increases, the resistance of the resistor changes. This is sensed by the seat heat module which varies the power supplied to the LH and RH seat cushion heaters, raising or lowering their temperature accordingly.
The resistors are connected to the LH and RH seat heat module on BLACK wires from the LH and RH seat heat modules to earth header C0708 on BLACK wires via splice joint 1.
So, if I'm getting 1.59v across light green and black, does that mean the resistor is working? I'm getting 12.5v at the pink, which is the powered wire, so I think I'm good on that.
Should I connect the red wire at the switch to something? Any other ideas to test?
I'd appreciate any help.
Thank yo
