'98 SL500; Can Fuel Gauge illum bulb be changed 'in situ'?

[daidnik]

I saw a thread here that said left-hand instrument cluster bulbs could all be accessed from underneath once knee bolster cover was removed.

I see all the warning lamps @ bottom and they are easy, but the cluster illumination bulbs are mounted higher and the plastic cover on the back makes thing tight and visibility is blocked. I got one changed that was higher and seemed like it was about centered on the fuel gauge but it wasn't the right one either.

I look at the view of the back of the instrument cluster in the service dvd and I see where the one I want is. I think I must have got the fuel reserve indicator lamp.

Can that left-most cluster illumination bulb be removed from underneath?

Is it covered up by the plastic cover?

I may have to make some of the puller tools if all else fails. I could get slight movement by pushing on the left side, but I see that the puller tools ARE required to get that cluster pulled forward.

Am I wasting my time with trying to do it from underneath?


David

[tecqboy]

I have pushed my cluster out from behind without the tools. I have a set of tools, but they are difficult to get aligned in the proper place and there is the extreme danger of scratching the plastic lens cover when using them. Try lowering the stering column all the way down, then disconnect the battery and push the cluster out from underneath. You can slide a credit card around the outside edge of the cluster to loosen the seal.

[daidnik]

Since you have seen the back of the instrument cluster, can you tell me if the plastic cover covers up the illumination bulb?

I may try pushing it forward again in a bit. I sure don't want to break that cover window.

I've also read that for simply changing that bulb, disconnection of the battery & harness connector to the cluster is not necessary, i.e. you can get it forward enough to get to the bulb.

Is this correct in your experience?

[tecqboy]

I've always just removed the cluster from the dash to change bulbs. What I've experienced is that it's not all that difficult to remove it. Once you do this for yourself the first time, you'll understand. And, I usually change all the bulbs while I'm in there. There are several high level integrated circuits on the VDO and I don't risk surge damage to them by disconnecting the battery. There are no mechanical connections to the cluster, just a big electrical plug and socket arrangement. There is a cover over the circuit board, but I don't recall if you need to take it off to get to the bulb in question. Last time I had it out, I changed the soldered in bulbs for the temp readout also. What I'd like to know is if anyone has replaced bulbs with LED's? There are now direct replacement LED's for most auto lamps.

[daidnik]

I can't seem to get enough push to get it past the spring clip on the bottom side.

I noted this sort of spring clip on the bottom side that has to come up over a ridge on the instrument cluster. I couldn't get it past that. I can only push on the left side as the key/steering lock pretty much blocks access on the right side.

I'll have to revisit this later.

Regarding replacement with LED's, I don't think these will be forthcoming soon. The form factor of the bulb & holder is pretty small. The LED can certainly be made small, but bringing the voltage down from 12V to under 2V would be quite a drop across a simple series resistor and the LED has a non-linear I/V curve so that complicates things.

The aftermarket 12V LED replacement bulbs that I have seen use a series-parallel connected array of LED's to better deal with the large voltage difference. I have bought some of these and ended up sending them back because they don't work well at all in reflectors not designed for them.

Hi power LEDs are definitely the way to go, but these are in new cars. They can last a long time, but I know the replacement assys are expensive. A $300 taillamp assy to balance with the $300 headlamp assy.