Help with Bulb ID and LED Replacement

[DBG8492]

Working to convert my interior 12v lights to LED.

The bulbs in there now are clearly marked 12v15CP. They appear to be standard 12v dual-contact bulbs. However, I don't see anything marked with those numbers/letters in the LED world - I see 15D or 15S.

Figuring that the "D" for "Double Contact" was the only thing that likely mattered, I bought a pack of five 15D to test, but they didn't work.

Does anyone know what will replace these bulbs?

 

[C lectric]

Talk to the vendors. They should be able to help guide you.

I did mine over 10 yrs ago.

Polarity matters with LED bulbs. Did you ensure the polarity is correct?


I think all that 12V15CP refers to is the operating voltage an the candle power of the bulbs.

 

[CharlieJ]

Enter m/n in Amazon search box...hundreds of candidates. Be careful to order the correct base configuration. Some double locking bases have offset locks.

 

[DBG8492]

Enter m/n in Amazon search box...hundreds of candidates. Be careful to order the correct base configuration. Some double locking bases have offset locks.

That's how I got the ones I had - ended up sending them back to the seller who even told me they should work and if they didn't there was something wrong on my end.

That may be the case, but all the fixtures work with the current bulbs so...

 

[DBG8492]

Talk to the vendors. They should be able to help guide you.

I did mine over 10 yrs ago.

Polarity matters with LED bulbs. Did you ensure the polarity is correct?


I think all that 12V15CP refers to is the operating voltage an the candle power of the bulbs.

You may be right - but those are the only numbers on any of the bulbs that I have to use to ID them.

The seller I bought mine from on Amazon assured me they would work and then said it was my equipment that was not working correctly.

 

[oguidry]

Contact:

https://www.doctorled.com/

Great website

 

[CaptTom]

Did you check the polarity? With incandescent lights it doesn't matter, so the fixtures could be connected randomly. I had to re-wire a few of mine when I went to LEDs.

 

[jgwinks]

Did you check the polarity? With incandescent lights it doesn't matter, so the fixtures could be connected randomly. I had to re-wire a few of mine when I went to LEDs.

Some builders even used the same color wire for + and - on lights. With incandescent it simply doesn't matter. The highest priced LED's have polarity correction circuits inside, but I don't think Amazon has those.
Some bulbs can simply be turned around in the fixture, but if yours can't, you'll have to take the fixture down and switch the wires around. Before doing that I'd connect the bulb to a 12v source and bare wires to make sure it actually works. Quality control on the cheapest ones isn't too good.

 

[C lectric]

Check the polarity. LEDs are polarity sensitive.

I ran into this years ago when friends were replacing the incandescents with LED and none of the LED would work UNTIL we reversed the feed wires polarity.

Then they worked.

 

[Flatswing]

Check the polarity. LEDs are polarity sensitive.

I ran into this years ago when friends were replacing the incandescents with LED and none of the LED would work UNTIL we reversed the feed wires polarity.

Then they worked.

You can also buy polarity insensitive LEDs cheaply on Amazon etc. but though these work great in my RV, I don’t use them on my boat because many cheap LEDs are prone to VHF & AIS interference per the USCG. For my boat, I use Marine Beam or Dr LED who sell quality replacements which are higher in price but do not cause radio interference and also are not polarity sensitive.

 

[ranger58sb]

Working to convert my interior 12v lights to LED.

The bulbs in there now are clearly marked 12v15CP. They appear to be standard 12v dual-contact bulbs. However, I don't see anything marked with those numbers/letters in the LED world - I see 15D or 15S.

Figuring that the "D" for "Double Contact" was the only thing that likely mattered, I bought a pack of five 15D to test, but they didn't work.

Does anyone know what will replace these bulbs?

Check out potential replacement bulbs on marinebeam.com. If nothing looks obvious, give them a call...

-Chris

 

[CharlieJ]

To help isolate the problem, use test leads and test the LEDs when connected to a 12VDC battery.

 

[backinblue]

Can you post a picture? I replaced all mine with LED from Amazon. Many of the new replacement bulbs will work with regardless of polarity. I also replaced some fixtures because the lens was cracked. Also from Amazon.

 

[DBG8492]

Can you post a picture? I replaced all mine with LED from Amazon. Many of the new replacement bulbs will work with regardless of polarity. I also replaced some fixtures because the lens was cracked. Also from Amazon.

Added a pic.

Also, gonna check the polarity - didn't think of that, but I bet that's the issue.

 

[DBG8492]

Welp...

Just tried running them straight to a battery - known good 12v source checked against an existing 12v15CP bulb.

Nothing - no matter which way the polarity was flipped.

 

[Bmarler]

Welp...

Just tried running them straight to a battery - known good 12v source checked against an existing 12v15CP bulb.

Nothing - no matter which way the polarity was flipped.

You’re saying the bulbs you bought don’t light at all?
Are you using the right contact configuration? If it’s a double contact bulb, there can be a couple of ways to power it. Either it’s powered from the two contacts on the bottom, or contact to base. I’d contact the vendor for clarification.
Changing to led shouldn’t be tough. I had to change some things on my fixtures as they were grounded to the case. The leds wanted to be powered at the contacts. So, some, but not all of my fixtures needed new bulb bases put in. Easy and inexpensive to do.

 

[C lectric]

Yes, contact your supplier.

Either there is some quirk about these bulbs wiring needs which you don't need or they are likely faulty.

Have you actually checked for voltage at the holders with a DMM.? I assume you have but one never knows. Maybe the supply circuit has a problem.

 

[Comodave]

Yes, contact your supplier.

Either there is some quirk about these bulbs wiring needs which you don't need or they are likely faulty.

Have you actually checked for voltage at the holders with a DMM.? I assume you have but one never knows. Maybe the supply circuit has a problem.

See post #15.

 

[Bmarler]

FWIW, the bulb style is a ba-15. If it has a single contact in the center of the base it fits a ba-15s if it’s a double contact on the bottom and the little keepers are parallel, it fits a ba-15d base.
Pretty sure it’s ba for bayonet, 15 for the diameter in mm, s for single d for double.
Offset keepers like an 1157 bulb take a different dual contact base. I’d have to look it up.
A single contact bulb uses the base for the ground, the double usually uses the second contact point for ground. Polarity can be an issue.

 

[DBG8492]

FWIW, the bulb style is a ba-15. If it has a single contact in the center of the base it fits a ba-15s if it’s a double contact on the bottom and the little keepers are parallel, it fits a ba-15d base.
Pretty sure it’s ba for bayonet, 15 for the diameter in mm, s for single d for double.
Offset keepers like an 1157 bulb take a different dual contact base. I’d have to look it up.
A single contact bulb uses the base for the ground, the double usually uses the second contact point for ground. Polarity can be an issue.

The original bulb has dual contacts - I think I said that earlier, but I'm not sure. And the keepers are not offset - they are the same height from the bottom of the base. The LEDs are exactly the same - dual contact, non-offset keepers.

With the original bulbs, they light by touching + and - to the contacts in either configuration.

With the LEDs, they don't light regardless of which side goes to which contact or if they go to any combination of contact or base including either polarity to both contacts and the other to base.

I sent the Amazon seller a message several days ago - before even posting here - but I haven't heard back.

I made the switch to LED on the sailboat using these exact same lights, and the original bulbs on this boat look exactly the same as the ones on the sailboat - they look like standard automotive dome light bulbs to me - which is why I was shocked they didn't work.

 

[rwaldrop13]

Here was a good site for LED bulbs- came from a similar thread. This links to a specific light but you can get to their home page from here

https://www.12vmonster.com/products/ac-dc-12v-24v-9w-120x-3528-cluster-led-light-bulb-e26-e27-screw-fitting-lamp-12volt-24volt

 

[rwaldrop13]

Another supplier site

Highly recommended

https://www.lumiteclighting.com/

 

[Circumnavigator]

Note that while you can use any bulb that fits for illumination, nav lights usually depend on a vertical filament to provide sharp cutoff at the edges of the visible sector as required by the COLREGS. It would be best to replace those with bulbs made for the purpose.


Jim

 

[DBG8492]

Note that while you can use any bulb that fits for illumination, nav lights usually depend on a vertical filament to provide sharp cutoff at the edges of the visible sector as required by the COLREGS. It would be best to replace those with bulbs made for the purpose.


Jim

Roger that

Right now, I'm just trying to replace all the interior bulbs. Nav lights will be at some point down the road.