I can't seem to get the instrument lights in my '67 Duetto to glow brighter. I purchased some new bulbs, and replaced one of the gauge lights, but it wasn't any brighter than the rest. Any suggestions or advice?
I would suspect a poor connection or corroded conector somewhere. You might try using a voltmeter(if you do not have one pick one up a Kragens for about $9) and measure the voltage at the dim light socket(should be 12V), from there you can work your way down the chain of lights and find where the voltage drop is. Also look closely at your grounds, they also could be corroded and providing more resistance to ground, and thus causing a voltage drop at the light socket.
Pepboys also sells ectrical terminal cleaner, and sealer. Might be a great time to clean all the connections under the dash, and then seal them.
Instrument lighting in Alfas was dim, at best, so don't expect much. Some of the bulbs were only 2w. Take one of the bulb out of the socket and run it directly off the battery and see how bright it is, compared to how bright it is installed. As Keven says, a poor ground is the usual suspect in these cases. I just got finished putting my dash back in after cleaning every single connection I could find, including wirebrushing grounding points, spade & ring terminals, etc. After 30 years under a dashboard with moisture evaporating from wet insulation, it's no surprise that unless cleaned up, these cars are going to have electrical corrosion.
If all the electricals check out OK, higher wattage bulbs can be installed. Since I thought the gauges were dim when I was young(er), I'll be putting in brighter bulbs myself. I researched this different bulb thing a while ago but after a quick look, I can't find it. D'oh! If interested, I'll dig a little further.
While goofing off a little at work, I found this thread on instrument bulbs. It looks like the size of the bulb depends on whether the bulbs are for a Jaeger or Borletti instrument; T3 1/4 minibay for Jaeger and G3 1/2 minibay for the Veglias. I'm not 100% sure though. You'd have to pull the bulbs and match 'em up. The T3 bulbs are available in 3W, trade size 1891/BP2 and 4.3W, trade size 1893/BP2. Haven't found a higher wattage G3 bulb yet but a G4 may fit (slightly smaller globe). Trade size 57, a G4 1/2 minibay bulb, is 3.1W, #257 is 3.5W as is an 1895/BP2. Then again, www.osram.com may have a higher wattage bulb too.
Thought about this.. can be done but there are a few issues..
1. LED's need some way to limit current.. i.e. a resisitor of the right value in series. Just hooking them up to 12v will blow them up. You pick one to give you the right current for the voltage you have (12v), different color LED's vary somewhat of what that value would be.
2. The mounting issues.. You need a way to hold the LED in the right position.. making a package that would fit in the bulb socket would be difficult for a DIY'er, and LED's tend to emit in a beam, narrow or wide, rather than a near 360deg pattern that a bulb does, so your light may not go the best places.. A more powerful LED could compensate.. The resistor could be spliced in the wire that powers the light.. more hassle and possible lack of reliability.
I guess you could make short resistor jumpers with fastons on each end, so that you dont' have to cut the original harness.. and take old bulbs and break off the glass, then solder the leads on the wires and epoxy the LED body to the socket for your replacement bulbs.. Hmmm.. may not be as bad as I first thought.
I could reccommend some mega bright wide ones, perhaps the amber would be a good color, there is a sort of turquoise (stoplight green) that is one of the higher output colors, and then there are the white ones, tend to be sorta bluish and not quite as powerful as the other two. Many sources for LED's but for the most powerful you need to look around... Try www.ledmuseum.org for more info on LED's than you want to know.. he's a freak about them, but in a good way...
Not sure if the cooler LED's would help or hurt with the gauge lens fogging problem.. I'd almost think that a higher wattage than normal bulb like mentioned up thread might work better by heating the gauge more.. Then again, very little heat and you may not move what water vapor is in the gauge around to end up condensing on the cool glass.. Overall, should be possible to end up with more light than a regular bulb.. Have to put this on my to do experiment list...
Hmmm... I just found out from Papajam's post above, I am talking about a different kind of light bulb here. My 73 GTV use the same light bulbs in the gauge pod as the one in the auction. In fact, I took one of the bulbs and match it to the LED one, the socket was an exact match, and the LED is slightly smaller in size.
I just didn't take the time to disassemble my gauge pod and put the LED one on. Maybe I should get some and try them on.
Quick question -
what does a T3 1/2 socket and a G3 1/2 socket look like?
Spent some time this morning pulling light sockets out of Jaeger and Veglia gauges as well as the sockets from the dashboard idiot lights. As applied to the 1750 cars, both brands of gauge use a G3 1/2 minibay bulb and the idiot lights use a T3 1/4 minibay bulb. Here's a pic of a G3 socket;
Geez. I wonder if I'll ever get this bulb & socket thing right. It seems I've reversed the bulb and socket designations. The socket in the first pic is a '1/2 minibay'. The 'G3' bulb Alfa uses in it refers to the size and shape of the bulb. The second pic is of a '1/4 minibay' socket that Alfa fitted a 'T3' bulb to and the 3rd pic is a '1/4 wedge' that also uses a 'T3' bulb, in this case, a #194.
Bulb sizes are NOT to scale.
the dash on my 72 GTV has two different size bulbs; the one or two if you will are a standard 18mm wedge bulb but the others, about the size of a pencil lead. What are the numbers for the brightest bulbs for each application and where can I find them please and thank you?