Dave said, "Some people just end up bypassing them."

I would do this before anything else. Who wants to dim these anyway? They're not bright enough under the best of conditions. Might as well be at max full time.

As far as LEDs go, I'm sure they have come a long way in 17 years but the ones I bought in 2005 for my '89 wagon were not nearly as bright as the halogens. I expect they are better now, though.


--
'79 242, '84 DL 2 door, '80 DL 2 door, '89 DL Wagon, '15 XC70 T6 AWD

How hard is it to get at the back of the 240 instrument cluster?
Thanks to Kittysgrayvolvo 240 photo it looks like the same lamps used in 740/940/850

You can buy new dash illumination "lamps with socket"
Goto Ebay and search: "CEC PC194"

Better and cheaper is to just yank the wedge bulb out of the socket and replace only the bulb with: Goto Ebay search "CEC 193" The socket never burns out.

CEC #193 Bulbs, 14 V, 4.62 W, W2.1x9.5d Base, T-3.25 shape (Box of 10) $6.08

Another option is to replace with LED wedge lamps that go in two ways and only
one way works (Since they are diodes)

Look at the options at Ebay for 193 LED wedge lamps. If it's easy to get at them then give a try. Dunno if they are dimable, I doubt it.
But they might be what you want and they are cheap.
Notice some have a printed circuit board base, and others have a molded plastic base with the wires for a contact. Maybe the PCB base is better, I don't know.
They also come in different colors.
If you like to tinker, try out the LEDs and report back.

For the idiot warning lights its the same story, buy with or without socket.
Replace only the lamps with "CEC E37"

Happy new year, Bill

Volvo RWD dash lighting, especially of that vintage, was notably not bright, presumably some kind of engineered intention so as not to affect night vision. I do recall them getting worse with age, presumably from rheostat contact wear/oxidation from repeated temperature change more so than actual use. Have you tried a good contact cleaner? Some people just end up bypassing them. There were a number of slightly different types used. In one I had, I think was a 140, I recall being able to file/bend/adjust something to get the contact wiper inside to go a little further that made a slight improvement. New replacements are available, probably better than going for used. I don't recall anything in the way of an electronic component on them, perhaps just a heat sink that shouldn't change with age.

I don't recall that this applies to 240s, but in the 700/900s the instrument cluster bulbs are spec'd as 5W, but often 3W is what's commonly available and used for replacement (3W is spec'd for the door markers). Although 3W is acceptable at night on dark roads, I'm now going back to 5W when I can find them as I find them better on well lit city roads. If you do a little research, you may be able to find a slightly higher wattage using the same bulb base in your 240. You should also pull a few bulbs to see if they've darkened/blackened from heat over the years. Then of course there's our aging eyes.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

There may be an electrical problem but it's also possible dirt on the bulb or the fixture is reducing the light. 40 years worth of dirt may be substantial. - Dave