One of the more common complaints from 4th Generation Monte Carlo SS owners is the dim gauge cluster. If you're like me, you have to squint to see your fuel level or other gauge readings at night.
The problem is the result of a combination of a few different factors. The lamps used to illuminate the gauges are not the brightest to begin with. The stock lamps (8 type 168 bulbs) are rated at 3 candlepower. In addition the gauges are not directly lit by the lamps. They are illuminated by reflected light from the back of the gauge cluster faceplate. The rear of the faceplate is a bluish color that darkens with age. Both these factors, combined with a few burnt out lamps make the gauges very dim at night.
There are a few things that can be done to alleviate the problems stated above. Correcting the dim gauge problem is quick, easy and cheap. This write-up details the following upgrades:
- Replacing low brightness and or burnt out lamps with new, high brightness lamps.
- Cleaning of the lamp connectors to ensure they are not resistive.
- Improving the reflection factor of the gauge cluster face plate.
There are a total of 8 lamps that are used to provide illumination to the gauge cluster. All but 3 of these are very easy to get to. The 3 in question are behind the speedometer. Removing the speedometer to get to these is not outlined in this write-up. To get to these 3 lamps, the speedometer would have to be removed, which requires disconnection of the speedometer cable. You can fix 90% of the dim gauge problem by just replacing the 5 easy to get to lamps. We recommend you start with those 5 first, then if you want more illumination, you can go after the remaining 3 lamps behind the speedometer.
When you expose and remove the gauge cluster, Tachometer and Speedometer as described in this write-up, DO-NOT attempt to clean the face of any of the gauges, the Tachometer or Speedometer with any form of cleaner or even water! The white paint used on the gauges, Tach and Speedo is water based and will instantly smear and disappear if you attempt to clean it with any liquid. At most, use a light dusting brush. Be very careful not to touch any of the pointers. They break off easily!
In addition, remember that the dash and electrical components become brittle over time. Do not force any part or over tighten any screw. Take your time and do not rush. If a part or fastener is stubborn, do not force it! The lamp sockets are especially prone to being severely brittle. Use caution when removing and installing the lamps.
The stock lamp type used in the gauge cluster for illumination is type 168 which has a rating of 3 candle power. There is one alternative for brighter lamps:
- Sylvania type 2825 lamps which are rated at 5 candle power. (Alternate part numbers: Wagner 17177, Philips 12961, GE W5W)
We recommend using the type 2825 lamps in this write-up. They are significantly brighter than the stock type 168 bulbs. You will want to turn down your brightness control (that's right.. turn down) when you use these to ensure bulb life and to reduce the amount of heat generated in the gauge cluster. The Sylvania 2825 bulb can be purchased at your local Pep-Boys or Autozone as well as other well stocked auto parts stores. In my case, I used one type 168 bulb, and 4 type 2825 bulbs to replace the 5 easy lamps on the cluster.
The following tools were used in the process of this write-up:
- Phillips head screw driver
- Stubby phillips head screw driver
- 7/32" hex nut driver
- 9/32" hex nut driver
- 1/4" hex nut driver
- Small wire brush (the type you clean battery contacts with)
- Very thin nail file or emory board
- Needle nose pliers
- Optional: Electrical Contact Cleaner
- Tooth brush to clean out cluster pod
The following are step-by-step instructions for disassembling the instrument gauge cluster:
- If you have a tilt steering wheel.. tilt it fully downward.
- Gauge Cluster Trim Plate Removal
- Image 1
Remove the four phillips head screws on the bottom of the cluster trim plate.
- Image 2
Remove the three phillips head screws on the top inner edge of the cluster trim plate.
- Image 3
Remove the cluster trim plate. If you have either the rear defrost switch and/or the passenger side mirror control attached to the trim plate, do not remove them, just rotate the trim plate to the right out of the way.
- Plastic See-Through Shield Removal
- Cluster Gauge Face Plate Removal
- Image 6
Remove the 7/32" hex head screw holding the upper right side of the cluster.
- Image 6
Remove the short 9/32" hex head screw holding the lower right side of the cluster.
- Image 7
Remove two short 9/32" hex head screws holding the transmission gear indicator on the lower left corner of the gauge cluster.
- Image 9
Gently remove the gear indicator by slipping it down and away. It is attached with a string to the steering column. Do not stress this too much.
- Image 9
Remove the gear indicator face plate by sliding it down and away. (now is a good time to marvel at the fact that there is another 3 speed non overdrive set of indications below it.)
- Image 7, Image 8
Remove the 1/4" hex head screw holding the left air-conditioning duct in place.
- Image 9
Remove the left air-conditioning duct.
- Image 9
Remove the 7/32" hex head screw holding the upper left side of the cluster.
- Image 9
Remove the 7/32" hex head screw holding the lower left side the the cluster.
- Image 10
Remove the cluster face plate.
- Image 10
Remove the Green turn signal film and foam from the pegs
- Gauge and Tachometer Removal
- Image 10
Remove three 7/32" hex head screws holding the center pod of four gauges (fuel/volts/temp/oil)
- Image 11
Remove the center pod of gauges by gently rocking it back and forth while pulling outward.
Image 12, Image 13
This gauge pod has prongs on the back which plug into a set of electrical clips mounted on the gauge cluster. Take care not to damage the gauge needles.
- Image 11
Remove two 1/4" hex head screws that hold the tachometer in place.
- Image 15
Remove tachometer by again rocking it back and worth while pulling outward.
- Image 14
At this point, you should be able to see the 8 lamps that illuminate the gauge cluster. 5 that are easily removed, and 3 behind the speedometer. You can turn your dash lights on at this point to see if any of them are burnt out. This image shows the location of the 5 easily removed lamps.
- Remove the lamps by gently rocking them back and forth while pulling outward. Take care not to aggressively rock the lamps as the lamp sockets can be brittle and may break. There is no twisting action to remove the lamps, they simply plug into sockets.
- Once removed, inspect the sockets to make sure they are in good condition. Take the small nail file or emory board and slip it between each contact of each lamp socket (make sure lights are off). This will clean the contact and remove oxidation which can cause lamps to be dimmer than normal. Again, use gentle small movements to ensure no damage is done to the sockets.
- Plug in the new lamps one at a time. Ensure they are seated all the way in each socket.
- Turn on your dash lights and confirm that all are lighting up.
- At this point I recommend you clean the gauge pod and tachometer contacts using a small wire brush. If you have access to some electrical contact cleaner, spray the prongs and wipe clean with a cloth. This will ensure that you have a good connection when they are reconnected, and will solve a lot of the low and erratic gauge readings that are common on the SS cluster. Also, make sure that the nuts holding the contact prongs to the rear of each gauge is secure. Take a needle nose plier to each to tighten them up. Again, a common cause of erratic voltage readings.
- Next, take the thin nail file or emory board and clean the electrical clips for the gauge pod. A few swipes on each side of each clip is sufficient to remove any oxidation that can cause erratic gauge readings.
One of the problems with the design of the SS gauge cluster is the fact that it is illuminated via reflected light off the rear of the gauge face plate. This face plate is blue in color and does tend to darken with time.
Image 16, Image 17
A great way to improve the reflection coefficient of the face plate is to paint the rear of it with a highly reflective paint. I chose a silver paint (Testors Model Paint). You could use white or a very light blue. Which ever color you choose, will be somewhat reflected on the gauges. My gauges no longer have as much bluish color to them, and have a more white illumination with the silver paint.
One step further would be to also paint the cluster sections around each lamp with the same reflective paint. This would improve the reflection coefficient more, although I chose not to do this, and it proved not to be necessary. If when you get done, you still want more illumination, this is an option to you.
Another suggestion offered up by Brian McMillan is to adhere aluminum foil to the reflective portions of the dash with 3M Super Trim Adhesive. If you go this route, make sure to keep the foil away from any exposed electrical connections. I don't recall there being any exposed electrical points, but just keep it in mind. This would certainly be the best reflection coefficient of all. If you try this, please let us know how it turns out.
Yet another suggestion offered up by Dan Grostick is to paint the lamp sockets with some highly reflective paint, instead of painting the rear of the face plate. Dan reports that this provides excellent luminesence of the gauges when combined with the lamp upgrade. Make sure you mask off the lamp socket contacts while you paint.
One suggested optional improvement is to remove the cluster housing by removing the four pal nuts that secure it to the car. Turning the cluster housing over reveals the printed circuit board. The light socket and gauge connections rely on a tension fit to the PC board. By soldering the connections to the board with a 25 watt soldering iron and rosin core solder, the lights will be even brighter and the gauges (particuarly the voltmeter) will no longer behave erratically. As mentioned earlier, since plastic parts can be extremely britle after many years of heated operation, use extreme care when handling and soldering the contacts. This suggestion comes from Joe Milko. Thanks Joe!
Before you close everything back up, make sure all of your indicator lamps (right side of the cluster) are working. To do so:
- Set your parking brake
- Ensure your seat belt is not connected
- Turn the ignition to the "ON" position, but do not start the car.
- Turn on your high beam headlights.
With all of the above conditions set, all of the indicator lamps should be on (BRAKE/OIL/CHOKE/SERVICE ENGINE SOON/HIGH BEAM/SEAT BELT). If any of them are not on, try wiggling the lamp to see if it will come on. If it does, remove the lamp and clean the contacts of the lamp socket, then replace the lamp. If the lamp does not light, replace it with a type 194 lamp.
Turn your turn signal in each direction to ensure the indicator lamps are working. If not, replace with type 194 lamps.
To reassemble everything, just reverse the order of the disassembly instructions listed above.
That's it! As you can see, it is very simple, quick and easy to do. The difference in illumination will be obvious when you get done. If you have any comments or suggestions that would make this procedure easier, or if you spot an error, please drop me a note. When I get back from my business trip, I'll add pointers and remarks to the images contained in this write-up.
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