I am curious about my rear seat heaters in the '05 VDP.

I talked to the PO and he said they stopped working (switches didn't light up red when pushed, no heat in seats) when he was driving the car. He took car to an indy garage and they said the fuse was blown, so they replaced the fuse and the switches lit up again. However, months later when he drove a passenger in the back, they said there was no heat to the seats, though the switch did light up to indicate it was on. He didn't do anything about this.

So I had complaints from back seat passengers about the seats not heating up. So I sat in the back and turned on the switch, and the switch would cycle through the 3 positions, but no heat to the seat. Same on left and right seat/switch.

So, as relates to my other post about getting dealer estimates for fixing things, this item was on my list for a quote. The dealer tech said the fuse is good, but no current gets to the seats. He said he tried bypassing the switches and feeding current directly to the seat heater, and the heater DID heat up from the current. So his conclusion is the switches must be bad, as they aren't giving the current to the seat heater (despite the fact that the switches light up and indicate they are doing so). His conclusion was to replace the switches, ordering new switches from the UK and he would install them which would fix the problem. The price quoted is $712 for parts and labor.

How can both switches fail simultaneously? The PO said he hardly ever had anyone use the left side seat heater switch, though the right side one was used frequently. The tech this week told me the switches do not light up red when pushed, but they do. I went to the car in the dealer parking lot, sat in the back, turned them on, and, while no heat, the left and right switches both lit up red. Went inside and told the tech they do light up red. His response: "No they don't". Well they do. Whatever the problem was originally caused the fuse to blow. Fuse was replaced. Why would a faulty switch not delivering any current to the heaters, blow the fuse? I would think a thermostat in the seat itself might be faulty, and could blow a fuse. The tech said as soon as he noticed the seats hating up when bypassing the switch he stopped the experiment and concluded the problem was with the switch. My concern is what if I replace the switch and the seats get current, heat up, blow the fuse (and the switch internals) and I am back at square one.

Anyone have any experience with your rear seat heaters on the X350 cars? Was the problem switch related? The tech's insistence that the switches were not illuminating when they have illuminated every time I've pushed them since I got the car doesn't inspire me with confidence that the switch is the real problem. The tech said that since the seats started heating up when he applied current to them it means they are fine and the actual heater is not the problem, just the switch controlling the current.

 

The switches might close a relay for the heater.. I don't have an electrical schematic but the fuse box diagram might give a clue.

 

If the tech is telling you the switches don't light up when you tell him you just checked and they DO light up, he is saying either, "I don't care, I don't want to spend time finding the trouble," or, "You are an idiot." I'd find another dealer.

 

Did you got the problem fixed?

I got the same problem. Every connection has been cheked, switches work, but no power to the heating elements.

 

Hi,

The tech sounds like he doesn't know what he is talking about.

The rear seat heaters are not controlled by a relay or the switches themselves, but by the REM (Rear Electronic Module). The switches send a signal to the REM, which processes that signal to turn the heaters on/off.

If you want to work on it yourself, make sure you download the Electrical Guide and look at the schematic.

If you want to find a tech who does know what he is talking about, find a Jaguar independent shop who has the IDS/SDD tool/system because he might better be able to diagnose the issue.