Is the correct LED replacement for the brake and reverse lights 1156 or 1157?

Thanks

 

Reverse lights are 1156.
Tail/brake lights are 1157.

 

 

Before putting LEDs into the tail lights be aware that they are NOT directly compatible with mechanical flashers.

If replacing only the stop/turn/tail lamps you'll need to install appropriately sized load resistors lest they flash much too slowly.

You can also replace BOTH flashers (turn and hazard).

If you replace the front turn/marker lamps with LEDs you must also replace the front side markers with LEDs as they operate in an odd push-pull fashion when flashing.

Also don't forget that you must use LEDs of the same color as the final color seen (i.e. red for the tail lamps and amber for the front). If you use "white" LEDs in the rear the color you see will be very washed out red despite the red lenses.

Finally be aware that to my knowledge there are no legally approved LEDs for use as turn signals, tail lamps, flashers, headlamps or marker lamps in most older cars to certainly include C3s. No problem with backup lamps.

 

So far I bought LED bulbs for the stop/tail/turn, backup and front signals. I got red bulbs for the brakes, white for reverse and orange for the front signals. Is the load resistor still necessary if I change all the bulbs in the back? I did not know that I have to change the front side markers if I'm changing the fronts. Do you know what the bulb size is for those? I'm assuming the 2 front side and 2 rear side are all the same size bulb?

Why would it not be legal to use LEDs in older cars?

 

The side marker lamps are #194

You cannot use the LEDs unless you install either load resistors on ALL lamps or electronic flashers.

Mechanical flashers in older cars work by heat of the current flowing through a very sensitive bi-metal strip. The current required for LEDs is so little that you will be extremely slow or no flashing. Mechanical flashers have the advantage of acting as effective lamp proving circuits as when one or more lamp in the circuit is out the dash indicator will show either a very slow or no flash.

I've read here of problems in the front when LEDs are used. The complication is that the front and side markers operate in a push-pull (one off while the other is on) manner when flashing. I seem to remember that even with all LEDs and electronic flashers the circuit will not work. I could be wrong in this but I am certain it is a real complication.

The reason that LEDs aren't approved in older cars is that there are very specific requirements for mandatory exterior safety lighting that include angle of view, intensity, color and likely other measures. The fixtures and lenses for incandescent and LED lamps are often greatly different because of the greatly different light spreads of LED and incandescent lamps. The major automotive lamp manufacturers like Sylvania and Phillps sell both LED and incandescent lamps. If LEDs are listed on their websites as suitable for use in older cars it's because they're been APPROVED. Most other places selling LEDs will not claim that the replacements are approved by any authority--only that they are physically compatible with the socket and most enclosures.

 

Thank you for the information. I'll test it out once the lights show up, otherwise i'll just return them and stick with the halogens.

 

 

As reported here before, LEDs and C3s often produce unusual results. That said, something tells me that your front and rear lamp harness grounds need a SERIOUS cleaning.

 

I guess it really is hit and miss with how these cars handle LEDs. The main reason I wanted them was to make the brake lights brighter, so I'm removing the front signal LEDs fixes the problem i'll leave it at that.

What do you say the grounds need cleaning? Can you tell me where the lamp harness grounds usually are so I can take a look at them?

 

No joke here. The reason your tail lights are dim is very likely due to a corroded ground connection.

The rear lamp harness ground is near the antenna. Look for the big black wire in that area.

 

The lights aren't dim, they perform like a normal halogen should. They're just not as bright as LEDs of course.