I currently have the front passenger seat removed from my vehicle (2003 HSE) due to some electrical faults. I have found and rectified the cause of the fuse blowing when reclining (wiring loom had rubbed on the seat frame), but am still problem solving the seat heater fault.

I have tested power - i.e. when the seat heater button is engaged power goes from the vehicle to the seat wiring loom.
I have checked the continuity of the heating elements - both are complete with no breaks in the wire. I have checked the resistance - 0.9 Ohm for the back and 1.5 Ohm for the base.

There is a potential issue in that the power input goes through the module - basically I have no continuity between the OW orange/white input wire into the AWR5160 module and the K pink wire output.
Testing the pins on the module indicates this is where the circuit breaks.

I know that the module is controlled by the thermostat switch which is part of the heater element for the seat base. Anyone aware of how this works? It's not on the circuit diagram in Rave - it inconveniently skips over the thermo sensor and module!

So what I am unsure of is whether the issue lies with the module or the thermosensor in the heater element.

 

Anyone know the difference between the two part numbers for the base heater element? Microcat lists AWR3418 to (V)3A824320 and HGT500040 from (V)3A824321. But some parts suppliers are advising that AWR3418 has been superseded by HGT500040?

It looks to me like HGT500040 has two wiring looms and so is not a straight replacement for AWR3418.

 

Ignore the above - I looked up the incorrect part numbers - those listed are for non-electric seats. Correct part number for electric seats is HGT500020.