kramttocs Posted May 5, 2020 Author Share Posted May 5, 2020 Took a look at this one. It reminded me that I actually bought some BA15D's awhile back to try for this. Cheap, junky ebay ones. They are too long for the underhood light cap to go over but even so they don't light up. Even if I rotate the contacts. I did notice when I looked at a similar ebay listing just now that it shows both bottom contacts are positive and the base is negative. I haven't tested the underhood light to know how it's wired. The link you provided I see it is polarity insensitive but don't see if the contacts are + or +/-. Looking here it has the comment about: Note that as with common 1142/BA15D/GE90 marine bulbs, the 2 bottom contacts are the power and ground, and the base shell is not connected. Not for use with antique automotive applications which use a different wiring configuration. Which if that is the real case and the underhood lamp needs the contacts to be + and - that would explain why the ebay leds don't work. Just chatted with a superbrightleds support tech and he confirmed that listing had + and - bottom contacts. Seems to contradict the polarity insensitive part though. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 5, 2020 Share Posted May 5, 2020 Just chatted with a superbrightleds support tech and he confirmed that listing had + and - bottom contacts. Seems to contradict the polarity insensitive part though. Marine bulbs don't use the shell as ground. The contacts are spring loaded and less prone to corrosion than the brass part of the socket. I have to assume he meant the contacts are both sides of the connection and that the bulb will still light either way. I hate having to test T style bulbs for polarity. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted May 5, 2020 Share Posted May 5, 2020 The lights from Superbright are the ones I used for my under dash lights, and they work really well. My truck is all LED inside, and if you turn on the footwell lights, dome light, and the map lights, it's daylight in there! I source my LED bulbs from ebay as I go for a 5 chip led bulb set. The ones that you typically find are forward firing and don't provide a nice uniform even lighting. I got a set of blue T10 wedge bulbs in my truck and I cant remember the one for the radio but when I pull my radio to service it I got a new led bulb that has two side firing LED chips and one forward firing that should help even out the lighting. I also got a set of warm white BA9S 5 chip led bulbs for my '56, but I might get something different cause on full brightness the bulbs are way too bright I think the low setting is about the right brightness for full brightness. and the lowest brightness setting Link to comment Share on other sites More sharing options...
kramttocs Posted May 5, 2020 Author Share Posted May 5, 2020 Marine bulbs don't use the shell as ground. The contacts are spring loaded and less prone to corrosion than the brass part of the socket. I have to assume he meant the contacts are both sides of the connection and that the bulb will still light either way. I hate having to test T style bulbs for polarity. Good point Jim. I'll pull out a spare underhood lamp and test the contacts to see what's going on. Based on that I'll feel more confident placing an order. Hey Rusty - Love seeing the photos of the dash lights (esp the 56) but let's avoid too many other bulb numbers floating around in this thread since it's specifically for the underhood light. There is a really good thread on dash lights here if you want to share your experience/feedback/results. As more of us go that direction, it's always nice to see what others have used. Link to comment Share on other sites More sharing options...
SCFlareside Posted May 11, 2020 Share Posted May 11, 2020 Good point Jim. I'll pull out a spare underhood lamp and test the contacts to see what's going on. Based on that I'll feel more confident placing an order. Hey Rusty - Love seeing the photos of the dash lights (esp the 56) but let's avoid too many other bulb numbers floating around in this thread since it's specifically for the underhood light. There is a really good thread on dash lights here if you want to share your experience/feedback/results. As more of us go that direction, it's always nice to see what others have used. How does the mercury switch work, so that the light comes on when the hood is open? "Silver" has the underhood light... I replaced the bulb, connected the wire and ,,, nada yet. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted May 11, 2020 Share Posted May 11, 2020 Good point Jim. I'll pull out a spare underhood lamp and test the contacts to see what's going on. Based on that I'll feel more confident placing an order. Hey Rusty - Love seeing the photos of the dash lights (esp the 56) but let's avoid too many other bulb numbers floating around in this thread since it's specifically for the underhood light. There is a really good thread on dash lights here if you want to share your experience/feedback/results. As more of us go that direction, it's always nice to see what others have used. Bulb in my underhood troubleshooting light is a GE90 bulb. The socket style is a BA15D which is how you can find a better selection of LED bulbs. Honestly there are not a whole lot out there option wise that would be very bright in my opinion. The best one from Superbright LEDs would be the following. https://www.superbrightleds.com/moreinfo/led-vehicle-replacement-bulbs/1142-led-bulb-w-stock-cover-12-smd-led-ba15d-retrofit-car/1978/ If you want to go else where this place is a marine site but they have the bulb and it has the larger chipsets which will emit more light. Those chip sizes are the same sizes found on the bulbs I stock for my personal vehicles. https://www.defender.com/product3.jsp?path=-1|65136|2312540|2312566|2312568&id=2363799 Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 11, 2020 Share Posted May 11, 2020 How does the mercury switch work, so that the light comes on when the hood is open? "Silver" has the underhood light... I replaced the bulb, connected the wire and ,,, nada yet. There is a glass ampule with two contacts in one end and a blob of mercury rolling around in there. Tip it up so the mercury covers both contacts and electricity can flow. You may have seen this in the ubiquitous Honeywell dome thermostats. A bimetallic spring, just like a choke housing, and the bulb on the end. It was an iconic bit of product design. I keep a few for using in projects. Link to comment Share on other sites More sharing options...
kramttocs Posted May 12, 2020 Author Share Posted May 12, 2020 There is a glass ampule with two contacts in one end and a blob of mercury rolling around in there. Tip it up so the mercury covers both contacts and electricity can flow. You may have seen this in the ubiquitous Honeywell dome thermostats. A bimetallic spring, just like a choke housing, and the bulb on the end. It was an iconic bit of product design. I keep a few for using in projects. Ordered the superbrightled one so will see how it works out. It's a tad bit longer than the ge90 but shouldn't cause any fits. Decided to see just how far the light would reach last night. Well it went pretty far but didn't want to go back in so ended up pulling if off, taking it apart, cleaning it, greasing it, and adding some extra tension to it. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted May 12, 2020 Share Posted May 12, 2020 Ordered the superbrightled one so will see how it works out. It's a tad bit longer than the ge90 but shouldn't cause any fits. Decided to see just how far the light would reach last night. Well it went pretty far but didn't want to go back in so ended up pulling if off, taking it apart, cleaning it, greasing it, and adding some extra tension to it. how hard was it to take apart and put back together? My wires were too short and I am not too happy with the leads I was able to solder on. Been wanting to take it apart and redo it but been apprehensive about taking it apart. Link to comment Share on other sites More sharing options...
kramttocs Posted May 12, 2020 Author Share Posted May 12, 2020 how hard was it to take apart and put back together? My wires were too short and I am not too happy with the leads I was able to solder on. Been wanting to take it apart and redo it but been apprehensive about taking it apart. Nothing to it at all. I was going to take some photos but there's really not much in there. Once you drill out the rivets the two halves come apart without fuss. Inside there is a white pulley made of two halves. On mine the two halves of the pulley came apart while I was pulling the case apart so the spring tried to escape but even if it does, no big deal. One half of the case will have a white lever that is the locking (clicking) mechanism and that's it. The other half has the mercury capsule and wiring. The pulley splits with some locking tabs. All I did on mine was wind the spring back in the center of the pulley (since it came out on me), put some dielectric grease on the contacts, and wrapped the light cord back inside the pulley. The spring center post on one half of the case has slot in it that the spring fits into. After putting the pulley back in I gave it a few revolutions until I liked the tension on it. Put the light socket in the holder and then put the other half of the case back on. I used SS button head m3 x 8 bolts with nyloc nuts and a washer. Reading that is probably more confusing that actually opening it Link to comment Share on other sites More sharing options...
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