Increasing brightness of car interior lights?

I've come to the conclusion that the interior lights my truck has are pathetic. They're not bright enough to see by and they are very yellow. I don't really want to go through the trouble or expense to put in LEDs. I think the bulb that is in there is halogen, it's about an inch long, and there are contacts on each end. Does anybody have anythoughts about a bulb that might fit in there and be brighter? Maybe a lower voltage bulb?

Ah man... trouble and expense are what it is all about! I made mine substantially brighter and at the same time more efficient. But it was QUITE expensive and time-consuming. The unfortunate fact here is that I have no answer for you, but I'm always looking for an excuse to post this picture /ubbthreads/images/graemlins/tongue.gif

Wow...I bet that is pretty bright. I would do LEDs, but I plan on selling this truck in a few months...

If the vehicle is old and you are discussing the overhead lights, try and take a look at the switch. My old car's overheads were a little dim, but I didn't really notice it until I pulled the switch one day and cleaned up the contacts. Better contacts created more flow, created bright light! Basicall for most cars, there will be two switches - one overhead that's marked Off/Door/On and one in the door. The one I pulled was the overhead O/D/O and it was basically a lever with a ball bearing on it that completed different circuits as it was moved. The ball and the contacts were oxidized badly. A little time with some metal polish and a toothbrush made everything much brighter.

Check the voltage at the terminals for the bulb. It should be 12.8 (car off) or more. Then check it again with the light on. A drop of 1 volt is common because of the length & poor connections of the wire used for these. If the drop is much more than that, then there is a serious (series!) resistance somewhere. It could be that the interior lights run off your dash dimmer (bad plan!). Cleaning connections like Blackbeagle suggested could pay off. Sometimes you can connect more directly to a power source & drastically reduce voltage drop. Most of these are about an amp load so a relay won't really help. But one of the cheapest easiest fixes is to convert the bulb to LED. I've used 3 white LEDs with about a 80-120 ohm resistor soldered in series to the dead festoon bulb terminals (superglued to the glass). Darell's setup works good for even more light.

The standard rule of thumb in checking voltage drop in automotive applications is no more than .1v drop per connector or switch. This does not refer to the reostat. I hope this helps.

Dan
ASE Master Mechanic 1982-2000