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Relay window voltage module C082M6531F required

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Help, just blew up the window relay.

can't find a new window voltage module anywere pn. C082M6531F, everywhere obsolete.
Also I have being looking for a alternative but don't know where else used. And as it is obsolete I think it might be Esprit specific. Only brand reference is BMI moulded in the plastic.

Any thoughts.

VAN DER LEE Turbo Systems     -

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  • 2 weeks later...

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Hello Jaap

Many apologies, I missed your post.

The window voltage module is indeed a mysterious device. It can be bypassed with some limitations apparently:

Does it have any part numbers or references on it at all, apart from BMI? It is extremely unlikely it was only manufactured for Lotus and I would be keen to find alternatives for the greater good as it indeed used on the S4, GT3 and V8. Actually, I will pull mine and have a look as well.

It is not completely obsolete though, you should still be able to get one from Lotus Garage in the US, $60 plus shipping and import duty I would guess?

Hope that helps.


I tempted my Esprit V8 IS in bits...(sob)

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  • 1 month later...

Lotus description: "Relay, window voltage module"/"Window logic module"
Lotus part number: *082M6531F
Manufacturer: BMI
BMI part number: 01210E
Cross references: None, specific to the Esprit
Status: Obsolete, SJ Sportscars, the Elise Shop, etc. may have stock


Module pic.jpg


Board layout.jpg





Car diagram RHD.jpg

Car diagram LHD.jpg

Car diagram US.jpg

"Window Logic Module. The windows are operative under any of the following conditions:

Non-USA cars;
- Whenever the ignition is switched on;
- During the period between switching off the ignition and a door being opened and closed;
- When either door is open;.
- When the transmitter key is used to arm the vehicle alarm, both door windows will automatically close
(unless the intrusion sensing has been switched off).
- When using the mechanical key to lock the car, if the key is turned and held at the locking position for a moment, both door windows will close automatically.

USA specification cars;
- Whenever the ignition is switched on.

Obstruction Sensing: On non-USA cars, a safety feature is incorporated into the window closing mechanism, such that if an obstruction is sensed (increased resistance) during the last third of the travel, the motor stops automatically and reverses window glass movement for a moment. This feature may be manually overridden to cope with frosty conditions and the stiffer window action which may result. An override button is provided in the tunnel top switch panel, and must be pressed together with the window switch. If difficulty is experienced in lowering or raising a window in extremely cold conditions, use a windscreen de-icer spray along the door to glass seal. Do NOT use radiator anti-freeze solutions, as these could seriously damage the paintwork.

WARNING: On non-USA cars, if the battery becomes discharged or the power supply interrupted (e.g. battery disconnected), the window system must be re-programmed after power reinstatement or neither the obstruction sensing or ‘one touch’ features will operate. To re-programme each window: Lower the window fully and keep the switch pressed for 5 to 10 seconds until a ‘click’ is heard. Then raise the window fully and keep the switch pressed until a ‘click’ is heard. Repeat the procedure for the opposite window."


US models do not use this module and window power is ignition switched.

Also info: at

This effectively turns RoW cars into US spec!


Remove the module and short pins 5 and 8 on the relay base with a jumper wire.

Workaround jumper.jpg

The windows and the switch illumination will work, but only with the ignition turned on.

Workaround pic.jpg

  • Like 1

I tempted my Esprit V8 IS in bits...(sob)

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  • Gold FFM

Nice one Alan.

why do folks over engineer things - can't wait to see if my logic thingy works. I kind of expect the Windows only to work when the ignitions on !!

Only here once

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  • 3 years later...

It looks like there is a small discrepancy between the board layout drawing and the circuit diagram. In the board layout Pin 3 (Collector) of the TR2 is connected to D1 and R6 and in the circuit diagram the same pin is connected R1/R6/pin 14 IC1/ etc.

I believe the board layout is correct.

Attached is the schematic I made (hopefully no mistakes) according to the board layout.



Windows Logic Module C082M6531F.pdf

And the corresponding PCB layout.


Window Logic Module PCB.PNG

Esprit Freak

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