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  Topic Review (Newest First)
12-27-2014 10:16 AM
JRMedved OK, I spent some time researching this and I have a definite answer. It controls the dashboard panel light dimmer. I realize that there is a potentiometer to the left of the glove box which for adjusting the dimming of the gauges, but this appears to be a dual system for whatever reason.

I tested this by activating the headlights and opening the glove box and accessing this mystery potentiometer. Sure enough, it changes the brightness of the dashboard bulbs, though not as much as the potentiometer/rheostat on the left side of the box. I cannot figure out why there are two, but there are. Try it yourself.

12-25-2014 12:22 PM
guyslp Would someone mind posting a photograph of the fuseboard that's being discussed?

I've attached the calibration steps outlined in IETIS, and while their not undecipherable they're certainly long and tedious. I'd be highly disinclined to mess with that calibration potentiometer if your ICE light is functioning correctly (or even if its never coming on and you live somewhere that's warm).

12-25-2014 11:54 AM
glove box POT

the var.pot. controls the ice alert.I was told not to touch but of course
I have.I'll wait till it's about 2 deg.turn it till if flashes up a warning.
12-23-2014 04:54 PM
guyslp Sorry that I can't answer the question just asked again, but the original poster asked about MasterTech and OBD-II.

As it turns out the basis of the Mastertech diagnostic system is the ISO 9141 standard. Several people have already figured out how to hook up an OBD-II port using a specific subset of pins in the Mastertech plug or via a secondary "bridge connector" that appears to have been on many, if not all, Mastertech equipped cars but that is tucked away and hidden unless the car was delivered to a market that required an OBD-II port as an alternative to the Mastertech port.

I am currently trying to gather more information about what was actually installed on cars destined for delivery markets where OBD-II was not legally required but the car has Mastertech. I'm seeking assistance with the research on the thread entitled, Research Assistance: Mastertech On Board Diagnostics & OBD-II.

Most of the active discussion about what is already known has been taking place on a thread I started on the RROC-Australia Discussion Forums entitled, Mastercheck Port & OBD-II - What do we collectively know?...

Any research assistance or contributions to the existing knowledge base would be most appreciated.
12-23-2014 12:05 PM
JRMedved I've noted that same thing (blue knob) in my Silver Spur. No one can tell me what it's for...everyone is stumped - even a Rolls-Royce master technician.

Curious to know if you ever figured out the answer to this mystery?

[email protected]
08-13-2012 01:02 PM
Brooklands LPT 1997 Potentiometer

Hi All,
Brooklands LPT 1997 glove box fuse board has a small PotentiometerÂ*on its own next to the blade fuse array. (not the dash gauge dimmer)
What does this small pot control ?

Also I have noted that UK 1997 LPT has no OBD II unlike in USA we have Master-Check with an Aircraft spec 34/48 pin round conector.
Has anyone manufactured/produced an adaptor or diagnostic program for this system ?
Or has anyone a contact recommendation for a Master-Check kit owner near Oxfordshire with a reasonable charge for plug in & health status check ?
Any advice welcome.

Best regards
Own a Bentley Brooklands LPT 1997

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