I just installed Nick Heiny's LED dome lamp upgrade in three of my cars and it works spectacularly, all for about $4 each. Does anybody have a good solution for the reading lamps in front of the dome lamp? They are anemic at best and would benefit from a a bright LED. But what fits? Ideas?

I posted Nick's solution to the new (yet unpublished) FAQ.
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See the 700/900 "FAQ" at the menu bar top screen left side.

Steve -

I plan on making a similar upgrade soon and will post my results (my parents are using the 940 at the moment so it may be a few weeks). From what I recall and based on the parts selector on Rock Auto, I think a 194/5W5/T10-type wedge bulb will replace the map light bulb. I plan on buying directional LEDs similar to these:

http://www.amazon.com/Wedege-Power-HYPER-WHITE-Lights/dp/B002JSFH3G/ref=sr_1_4?ie=UTF8&qid=1358656264&sr=8-4&keywords=led+194+bulb

http://www.amazon.com/Oracle-Lighting-T101L1CW-White-Wedge/dp/B0050VGVQQ/ref=sr_1_13?s=automotive&ie=UTF8&qid=1358656316&sr=1-13&keywords=led+t10+wedge+bulb

http://www.superbrightleds.com/moreinfo/miniature-wedge-base/194-led-bulb-1-smd-led-wedge-base/204/


I also plan on rehabbing the map light rotary switches. Mine are broken and pushed in. It seems to bee a common problem. From what I can tell, the original design had a piece of metal fastened to two plastic posts that held map light socket in place. This fastener resisted the upward pressure exerted when rotating the map light switch that acts directly on the map light socket. When this flimsy metal thing breaks, the map light rotary switch gets pushed up into the base of the dome light. If I can do some barn door engineering to get them functioning normally again, I'll also post another update as we find map lights essential when traveling with a little one in the car.

One other idea I've been mulling over was to add a 4th brake light at the top of the tailgate. For enhanced visibility, Volvo raised the height of the center high mounted stoplight (CHMSL) and other signal lights on the 850-forward. With more and more SUVs on the road, the 940's CHMSL at the bottom of the tailgate glass is only as high as some bumpers. I'd like to get something higher up to catch the eye. Daniel Stern has an ~$80 LED replacement piece, but I'm hesitant to remove pieces from the OEM brake light setup - I'd rather just add. I'm thinking about grabbing a LED CHMSL from another vehicle at the junkyard and seeing if I can install. Many people use the trailer hitch to add a 4th brake light, so I don't think it would be unusual or attract attention from the local gendarmes to have a 4th brake light.

Would I ruin anything by tapping into the existing CHMSL wiring? I can't see anything in the FAQ that would indicate the brake light circuit must have a certain amount of resistance to disengage cruise or anything weird like that and the additional amp draw would be inconsequential.

I added a center brake light to the 164 several years ago and if you
use two diodes to isolated them and connect one to each side so there
is the same amount of current drawn from each side it will not
light the warning light. It looks for a unbalance between sides.

I had mine apart yesterday to install the LED dome lamps. You are correct about the slide switches. They press against the bulb holders which in turn are held in place by a metal strap secured by flimsy plastic posts with hot-melted ends. This is guaranteed to snap off. There may be a way to use fishing line to secure the bulb holders against the underlying frame. There may also be a way of gluing a holder across the top of the bulb mounts to keep them from moving upwards when the switch is pressed from below.
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See the 700/900 "FAQ" at the menu bar top screen left side.

The brake light upgrade idea is noble but I have a feeling it will cause the lamp out relay to activate.
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See the 700/900 "FAQ" at the menu bar top screen left side.

"Would I ruin anything by tapping into the existing CHMSL wiring? I can't see anything in the FAQ that would indicate the brake light circuit must have a certain amount of resistance to disengage cruise or anything weird like that and the additional amp draw would be inconsequential"

Not sure about affecting cruise but it is almost guaranteed pop the brake failure warning light. The trailer wiring kit supplies supplemental voltage just for this reason,

Also keep in mind that the passive safety features of the Volvo are part of what keep us safe as well. Try not to limit any of our exceptional rear visibility )actually better that the 240).

Thanks for the info on the bulb failure light issue - I didn't think of that.