| Author | Message | ||
     Edward Mckinley New User Username: ed_mckinley Post Number: 7 Registered: 2-2013 |
I have no instrument lights or gear selector lights operating on my 89 corniche. Wondering if the diode panel behind the fuse block is a probable suspect? The other interior lights are working fine | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 666 Registered: 6-2009 |
Ed, That's a possibility, but I'd check ground/earth issues first. I had entire "chunks" of lighting that was non-functional on my Shadow II that was due to nothing more than corrosion where the ground straps connected to the metal part of the dash that all the lights in those "chunks" used as the common ground. Sorry I can't be more specific, but this fix is about five years behind me. Brian | ||
| Edward Mckinley New User Username: ed_mckinley Post Number: 8 Registered: 2-2013 |
Thanks Brian, I was hoping someone might know where The actual ground connection is before I go taking the whole dash apart. | ||
| Mark Herbstreit Prolific User Username: mark_herbstreit Post Number: 112 Registered: 5-2005 |
Hope I'm not stating the obvious but have you checked you haven't just knocked the instrument light dimmer to its lowest setting? | ||
| Edward Mckinley New User Username: ed_mckinley Post Number: 9 Registered: 2-2013 |
I have definitely check that :-) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 667 Registered: 6-2009 |
Mark, never hesitate to suggest "checking the obvious" because it is so frequently and easily overlooked when stress sets in. Also, as rheostats age and collect dirt they often get "wonky." If you get irregular flickering when adjusting this, or if the lights suddenly come on when you get to the "full on" setting when turning, but then go off when you let go, suspect a bad rheostat. These often respond very well to a squirt of TV tuner cleaner and a few turns to get everything working again. Brian, who often reacts badly (in private) to those suggestions simply because they turn out to be correct! | ||
| Edward Mckinley New User Username: ed_mckinley Post Number: 10 Registered: 2-2013 |
According to TSD 4701 there is a panel lamp electronic control unit which seems to have commonality with the lamps which are failing, although I'm not sure exactly what it does. From the manual it is located in the far right lower area behind the fuse panel | ||
| Bill Coburn Moderator Username: bill_coburn Post Number: 1525 Registered: 4-2003 |
Edward/ You get the bottle of Scotch! I managed to short out this unit when replacing the speedometer on my '84 Spur. I handed the problem to my resident genie who pulled the unit apart and it was U/S. Somehow he connected it up so that my dash lights come on full blast and cannot be dimmed. Since the lights are equivalent to the bum of an incapacitated fire fly I haven't bothered replacing the unit. | ||
| James Feller Grand Master Username: james_feller Post Number: 324 Registered: 5-2008 |
Such a common and bemoaned problem Edward by a lot of us. I too have replaced the dimming restat in my 86 Spirit as it was giving such poor illumination it was annoying and almost unreadable at night, I checked fuses and relays and nothing cured it till I replaced the reostat. As Bill suggests the instruments even on full intensity are frankly not brilliant in either light intensity or readability at night compared to modern cars. My 89 Turbo RL dimmer or rheostat has only ever been on full intensity with no 'dimming' via the knob, so rather than replacing this I left it well alone as frankly dimming was not desired anyway. So the upshot Edward is if you cannot get the reostate working with some lubrication then I suggest it may need a working exchange part. Just a question....occasionally I did blow the instruments fuse when fiddling as I have a want to do at times.....thus no instruments or the lights at all till I put another fuse in...I think its the I.C.E fuse 10amp....you do have working instruments yes? anyway some great suggestions for you here to get cracking on with. Let us know how you get on. Cheers J | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2940 Registered: 4-2003 |
If you don't mind them bright all the time with only limited dimming possibilities, fit LEDs. With white LEDs they can look rather smart, and the narrow light bandwidth at around 4500 Kelvin they are not too dazzling. Go for multicoloured LEDS if you are game !! RT. ps: on 1987+ cars there is an adjustment on the dimmer ECU located behind the fuse panel. If you turn the tiny knob clockwise it ups the range of intensity with conventional incandescent bulbs. I don't know whether pre-'87 cars have the same ECU but shall check. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2942 Registered: 4-2003 |
pps: on cars with the LED array for the warning lamps and gear range indicator, if you have an airbag NEVER power up the speedo nacelle with either the tacho plug or speedo plug disconnected. That does not trigger or disarm the airbag, but brings up a permanent dreaded AIRBAG warning until it is cleared by the diagnostic hand-held interrogator (if you have one) or by another devious method described in this Forum. Yep, I learned the hard way when fitting LEDs to my Conti R. Remember, when fitting an LED there is a 50% chance that it is back to front first time. Fit them all, reconnect the looms and note which ones are out. Then simply reverse the ones not illuminated. RT. | ||
| Edward Mckinley Experienced User Username: ed_mckinley Post Number: 11 Registered: 2-2013 |
OK, now I'm lost. The manual I have isn't completely clear on the location of the common grounds for the panel lights and I cannot locate anything that appears "open". The light on the console is working correctly as is the jewel light on the ignition. However, all the panel lights on the dash (speedometer, clock, outside temp and the gear selector light) are all out. Any ideas would be welcome Thanks | ||
| Edward Mckinley Experienced User Username: ed_mckinley Post Number: 12 Registered: 2-2013 |
FWIW, when I turn the potentiometer for dimming the panel lights it does dim the light on the console 1989 Corniche II | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 683 Registered: 6-2009 |
Ed, While I'm sure the locations of the ground wires are probably "standard" I don't know what that means for a Corniche. All I can tell you is that it was very easy to locate all of mine once the wood and/or top roll and/or other panels that hide bits in specific areas were removed. I do recall that the lights for the panel above the knee roll had a short ground (or several) that was easily visible once you could see back to the metal structure that holds all of the dash and upper console stuff. Everything you've described up to now just screams "bad ground/earth" to me. I think you're going to have to dig around no matter what, so you'd might as well initiate yourself to taking the dash "decorative" material off so that you can see what's what. Brian | ||
| Edward Mckinley Experienced User Username: ed_mckinley Post Number: 13 Registered: 2-2013 |
I have the dash panel off, as well as the knee roll. I see the common earth point is in the footwell left of the emergency brake and although it looks to be making good contact I loosened it up moved things around and re-tightened for good measure. Still-not lights | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 684 Registered: 6-2009 |
Ed, Well, it could be that the arrangement in my car was secondary to its unusual past, but I distinctly remember the knee roll area had a ground strap much like those found around the chassis that was the grounding point for all those lights and was connected directly to the metal structure of the dash. Have you checked for continuity between the "other end" of the wire/strap and the end you've loosened/tightened? They can go faulty. Also, just for laughs, try checking for continuity between its attachment point and some other point on the chassis. If you could post a picture of the area you're describing it would at least help me to get a clearer picture of "the lay of the land" in your car. Additional front shots of the dash area might lead someone to see something, too. Brian | ||
| Edward Mckinley Experienced User Username: ed_mckinley Post Number: 14 Registered: 2-2013 |
I think I need a correct wiring diagram for my car. The one that I have is for 1988 and there are differences that I am noticing. It appears also that the Corniche follows a different diagram than the Spur, etc. | ||
| Edward Mckinley Experienced User Username: ed_mckinley Post Number: 15 Registered: 2-2013 |
Brian,any idea where I might get a wiring diagram for my car? I have a few manuals but they seem to end at 1988 for wiring for some reason | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 687 Registered: 6-2009 |
Ed, Check your e-mail. If anyone knows whether hard copy is available for any/all years, and from what sources, this would be a good place to list those or an excuse to start a new thread containing same. Brian | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 690 Registered: 6-2009 |
Ed, Have you looked at Section 20 - Instruments & Warning Lamps and Section 21 - Panel Illumination in TSD4701 - Electrical Supplement to the Workshop Manual? The images there appear to be relatively clear. Since I am not good with wiring diagrams they're not "clear" to me, but graphically they're clear. Brian | ||
| Edward Mckinley Experienced User Username: ed_mckinley Post Number: 16 Registered: 2-2013 |
Page 21–13 reveals ground number 39 which I have checked, and also splice 11 however the physical location of splice 11 is not revealed in the corresponding pages so the mystery continues |
