The rheostat on my light switch get very hot when I turn the down the instrument lights. They're way too bright at full on.
Every other aspect of the switch works good.
Is there a switch with a better rheostat, or another solution?
Separate instrument light control?
How about lower wattage instrument bulbs?
Here is the switch.
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Try inserting a resistor between the switch rheostat and the dash lights.... This will lower the curent throughout the rheostat and dim the dash lights a little or a lot depending on the size of the resistance.... wattage should be something over 25 watts I believe..... Toyota trucks (Tacoma), and others, use a thumb wheel rheostat that snaps into a rectangular dash opening... over the counter dealer (expensive?) part.... Take a curent reading on the dash lamp amperes, multiply that by 13.2 v and you have the required wattage for your problem.... If still in doubt, go larger... An Ohm meter reading across the present rheostat will tell you where to start looking for your dropping resistor.... Hope this helps...
Thanks for the reply, Leon.
I'll break out my multi meter and do some measuring.
Too bad Radio Shack pulled out of our town, now I'll have to venture out further for resistors.
CG
Most complain about not enough light in gauges! There are replacement LED bulbs for the gauges - which wouldn't take much effort by the rheostat (so not heat buildup) to regulate them. You can get them in different colors too - amber, blue, green, ....
They're so bright, they reflect off of the windshield. Kinda like a cheap heads up display, but annoying.
The LED idea sounds good, but I don't know if LEDs will work with a rheostat?
Carlos, I posted about this when the heat from the dimmer finally burned up my switch.
I chose to do what Leon suggests - put a resistor in series with the dash lights to dim them. VS sent me a new switch, but it was the same low quality as the first, so I didn't want to risk using the dimmer circuit in it again.
Leon's right - you need a resistor with a very high wattage rating. I used a combination of four 8-watt resistors to distribute the heat.
There are a few different things contributing to the problem:
- First, my gauges came with five-watt bulbs - way too bright, and the six of them together use 30 watts - almost as much as an old school sealed beam headlight. One-watt bulbs would be more appropriate, but they're harder to find. LED bulbs sound like the best solution, and if you find the right brightness, you won't need to dim them.
- Original VW's had only two (or three) bulbs - a speedo and (later) a gas gauge. Our cars have six bulbs. More bulbs = more watts, more heat, and a lot more power to be dissipated through whatever you use to dim them.
- The switches on original VW's weren't made in China by the lowest bidder.
If you search here, you'll find a lot of threads about failed headlight switches. While it's a very good idea to add relays so that the heavy current for the headlights doesn't go through the headlight switch, I'm convinced it's the heat from the dimmer rheostat that makes most of our cheap, repop switches fail.
Once you determine what resistance and wattage you need, you can order it (them) from ALLIED ELECTRONICS over the net using your credit card, and delivery isn't a real deal breaker as ALLIED is way cheaper than the normal retailer.... Good luck with the project....
LEDs would have an extremely narrow "window" of adjustment with the stock rheostat.
LED brightness is usually controlled by changing the duty cycle, that is by flashing them on an off at a high rate that isn't detectable to us. The ratio of the time the LED is on to when it is off determines how bright it appears. Doing something like that would require a digital controller that would be more trouble than you want to deal with. This is a place where old school is much easier.
I removed 3 of the 6 lights in the gauges and I think that might work. I had to go out to do a road test of course.
Mine are 4 watts, but I found some on the web that are 2 watts.
http://www.elightbulbs.com/Osr...utomotive-Light-Bulb
I might try them out.
I do want to add brake lights behind the grills and reverse lights in the rear. I'll use LEDs for those.
I might use two of these for the brake lights behind the grills. They have a cool turn signal feature to them, and they're the same width as the grills.
http://store.ijdmtoy.com/LED-B...al-Lamp-p/50-075.htm
CG
Beautiful car Carlos.
I added a third brake light behind my grill and used a similar product but without the turn signal option. I would have but I didn't see them in the store. Anyway, here is a link to what I did if you need some ideas:
Carlos, nice ride! I added a frame under the grill and a couple big round truck lights and hooked them up to the brake circuit. Definitely helps. I was rear-ended in the Spyder back in 2006, so I thought they were very necessary.
RE: the rheostat, I got a old Bug 6v headlight switch. It is much more robust(read German quality) and can handle more current than that cheap 12v one in your hand in the picture at the top.
And for all you Speedster folk, the Spyder doesn't have anywhere near the dash eyebrow that Speedsters have. So glare can be a real issue at night. Carlos, if you do dim it, you will still see the glare. No way to eliminate it without extending the dash. After a while you get used to it. I don't even notice it anymore, but that is close to 40,000 miles of experience talking.
Oh, and FYI Lane, you can make a really cheap PWM(that's pulse width modulation) generator for about $10 to drive those LEDs. And you could use the OE dimmer to do it.
Carlos, I added reverse light as well. My battery is in the left rear. Under it I mounted a small halogen clear driving light, the 55 watt kind. Also a relay to trigger it, reverse light switch is grounded on one side, other side of switch grounds the relay. 12v switched from up front to the relay coil. 12v from battery to hi-amp contact on relay.
It really lights up where you are backing, but you can't really see it, unless you are laying on the ground.
LED dash light bulbs are out of my price range, but nice product. Walmart sells small "driving lights" which will make for good reverse lights, if mounted under the body. They come in 35 and 50 watt ratings, I believe. Or, if you find a good used set of chromed housing reverse lights, only used on the 1967 Beetle, those mount easily and look good and are study German units. Steel housing, not plastic.
