Rolls-Royce and Bentley Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
80 Posts
Discussion Starter #1
90 Bentley Turbo R.

Dash lighting does not work..

The rotary panel lamp dimmer seems to be the initial problem. Looks like it came undone and the entire dimmer switch rotated to the point where the three wires to the dimmer switch all broke off the terminals on the back of the dimmer switch.

Getting the dimmer switch out involves a lot of dash/center console dis assembly that i am working through. I can see the three wires torn loose with a light but gettting the switch out has not been accomplished yet. Working on it.

I sourced a brand new rotary dimmer switch just to be safe. It has three terminals, marked "b", "c" and "a". Found a wiring diagram and identified "purple/red", "blue/green", and "red/green" as the relevant wires to the three terminals on the rotary dimmer but no idea as to which wire goes to which terminal.

Any suggestions?

Paul LeClair
 

·
Registered
Joined
·
80 Posts
Discussion Starter #3
How do you know this? Yes, perfectly answers the question I spend about four hours yesterday searching through every resource I could find. Thank you very much!!

now I just have to get at the back of the switch, the center console between the seats needs to come out to get at it, which involves having to remove the fascia of the dash of all things. Working on it, carefully.

Thanks again!

Paul LeClair
 

·
Registered
Joined
·
80 Posts
Discussion Starter #5
got the old switch in, new switch wired and in place. Cut the heck out of the back of my right hand and the car learned a few new swear words. Unbelieveable how much disassembly is required to get the center console detached to get at the panel dimmer switch from underneath, the upper dash has to come apart, the car is put together like a tightly fitting jig saw puzzle. Have mnot reconnected the battery yet to test the new dimmer, I am already in so deep there are a few other things thta need doing in the dash "while I am at it I might as well......"
28157
28158
 

·
Registered
Joined
·
80 Posts
Discussion Starter #6
sorry for various typos in previous post, including saying got the old switch in, meant to say got old switch out, etc. Apologies.

Next step is taking instrument cluster out for some needed attention, which appears to require taking the dash roll top off as the top brackets of the instrument cluster go under the roll top, Need to take the dash roll top off anyways to try to get at whatever the source of the climate control squealing noise is when it is adjusting itself, must be some sort of actuator/stepper motor or something, time to spend a few morehours with the various online manuals
 

·
Registered
Joined
·
25 Posts
Hello,
I took out main instrument cluster (this with speedometer, dip and tachometer) lately. To do it, there is not needing to put roll top off. But you must be very gently with wires and connectors. There are three of them - white, yellow and blue...


28159
 

·
Registered
Joined
·
80 Posts
Discussion Starter #9
thanks all helping me to get to this point. I had to remove the screws for the dash roll top as the top brackets of the instrument cluster were trapped under the top end of the roll top.

Once i got the instrument cluster out it was readily apparent I am not the first person who has been in there. The instrument cluster in my 1990 Turbo R has a date sticker on it of June 1995....

Of concern is someone has not been very kind to the instrument cluster wiring on the yellow plug, including tapping into what looks like a red(maybe brown)/green wire/ with a ScotchLok insulation displacement connector, and further evidence of tampering with other wires into the plug. I need to follow the larger white wire tapped in and see where it goes, as well as figure out how to take the yellow plug apart and check its internal connections.

third image inserted below is of a disk shaped object connected to a crank mechanism. There is another further to the right behind the center console. I am guessing these are the actuators for climate control? If so I am guessing they are what makes a horrible screaching noise when the climate control is adjusting temperature/function? If so, can they be lubricated or rebuilt? Any information or suggestions welcome, I will have a look at the online manuals on the weekend and see what I can find.

I tested my dash lighting before I took the instrument cluster out. With a new dimmer switch the dash lights still do not work. I have now ordered a new to me (used) ECU for the dash illumination from IntroCar, will be interesting to see how long shipping England to western Canada will take in the time of CoVid 19. I sent a parcel from Canada to the UK March 21 paying for 3 - 5 day international delivery, as of April 8 it still has not made it to its destination on the UK, good thing I paid for insurance......

28160
28161
28162
 

·
Registered
Joined
·
25 Posts
I am convicted that green-brown wire has +12V when the key is in ACC or Ignition-On position. Probably one of previous owners connected there any accessory...
Red-yellow (I see it is wrapped in duct tape) is a speed signal from ABS module (there is no other speed sensor in gearbox like in other cars), I believe.
 
1 - 10 of 10 Posts
Top