Exige S HVAC Control Panel Removal

[LotusPilot]

Hi folks - can anyone provide some guidance on removing the HVAC Control Panel assembly from an Exige S?  This assembly appears to be one something that the otherwise very thorough Service Manual doesn’t provide any indication at all as to how it is fitted - or how to remove it from should controls need to be repaired.

The heater control panel backlight seems to have completely failed.  Despite turning the dash illumination to maximum, to ensure that power is reaching the panel, my heater controls remain as dark as soot.  As is, in the dark, you can’t see where the control knobs are positioned.

[GFWilliams]

Did it ever light up?   I didn’t think the Exige S was lit at all 

[LotusPilot]

Yes.  It has always previously been lit, with variable brightness - until now!

The Lotus circuit diagrams indicate that the panel is fed directly from the main instrument cluster.  I am hopeful that it’s simply a dry joint - in the HVAC panel - that can be fixed.  However, I have to get the panel out to fault-find - hence my question here...

Edited December 7, 2019 by LotusPilot

[Kristof Thys]

10 hours ago, GFWilliams said:

Did it ever light up?   I didn’t think the Exige S was lit at all 

I was wondering the same.  I guess I haven't driven my car more than once a year in the dark, but last week I was thinking "well didn't that panel used to be illuminated?"... then again, the wiring diagram does read on connector A10, pin 6&7 for back light of the instrument cluster.

 

16 hours ago, LotusPilot said:

Hi folks - can anyone provide some guidance on removing the HVAC Control Panel assembly from an Exige S?  This assembly appears to be one something that the otherwise very thorough Service Manual doesn’t provide any indication at all as to how it is fitted - or how to remove it from should controls need to be repaired.

The heater control panel backlight seems to have completely failed.  Despite turning the dash illumination to maximum, to ensure that power is reaching the panel, my heater controls remain as dark as soot.  As is, in the dark, you can’t see where the control knobs are positioned.

There should be two screws on the bottom (through the alu thingy) to remove and then you need to push on the top, 2 clips left and right for it to pop out.

 

 

Edited December 7, 2019 by Kristof Thys

[Kristof Thys]

As a follow-up, seems that if you have the instrument cluster illumination turned down all the way (like I have), but not completely out on the dash, the HVAC controls don't light up.

 

Increased illumination level and presto, HVAC controls lighted.

 

[LotusPilot]

Thanks for the replies.  As I said, all used to work - with variable backlight controlled via the dimmer.

Kristof - screws are already out, but nothing budges.  Can you expand upon what/where/direction to apply pressure to release the clips?  I’m reluctant to get to feisty without knowing the “knack”.  From experience, I known that some bits of trim can be fragile.

Update - with screws out, the top two clips have been located and unclipped.  The panel housing (part #7 in Section 14.05 of the parts list) seems to be somehow fixed to the curved support section (#8)  that sits below the control panel housing (into which the two screws, already removed, engage).  The parts listing shows the support section and the control panel housing to be two distinct separate parts, but not a clue on how they are fixed together.  Unless they can be separated, I can’t see how it will ever be extracted as a single unit - and until its out, you can’t reach the connectors inside the housing.

Edited December 7, 2019 by LotusPilot

[LotusPilot]

Okay, for anyone reading this thread, the key to getting the HVAC panel out is to not remove the two screws under the dash.  Leaving them in is necessary - as it keeps the HVAC Panel and its support structure correctly aligned.

To remove the HVAC panel, gently apply downward pressure on the top edge of the panel, about a centimetre from either end, whilst pulling slightly forward to unlatch the hidden clip - then repeat on the other side as there are two clips in total.  Sliding a credit card into the gap at the top edge might help prevent the clip from re-engaging at this point.

Whilst the clips are unlatched, you need to simultaneously wriggle and slide the HVAC Panel housing directly towards the rear of the car - keeping it level throughout.  Some significant “persuasion” may be necessary as the HVAC panel is tightly engaged with the support panel; provided that the lower screws remain in-place, with application of sufficient force, the panel will “slide” off the support panel - the latter remaining captive within the trough.  

Once out, you’ll note that their are two longitudinal slots on the bottom of the HVAC Panel housing that engage (are an interference fit) with the edges of the captive support panel.

If you do subsequently remove the support panel, you should note that each screw has a nylon washer/spacer between the aluminium trough and the plastic support panel.  This needs to be replaced as found.

Replacement of the HVAC panel is essentially the reverse process - aligning the edges of the support panel with the slots in the underside of the HVAC Panel - wriggling and sliding (actually more akin to heavy persuasion than sliding) the panel back into place.  
Finally, on the top edge of the panel, push back and up to reseat the clips.

 

Having removed the panel, I managed to confirm that the backlight is indeed an EL backlight, positioned on the front side of a thick aluminium plate.  All panel switches and rotary controls pass through the backlight panel and the backplate.

In my case, reseating the relevant connectors did not resolve the backlight issue - suggesting that either the inverter module, located on the back of a PCB mounted on the back of the aluminium panel, may have failed - or the circuit that drives the inverter from the Instrument Pack is itself faulty.  More investigation will be necessary.  It is worth noting that the inverter module circuitry and EL backlight are represented as a single “lamp” symbol on the Lotus circuit diagrams!