Does anybody have any idea how to make LED 1157 tail/turn signal/brake and front parking/turn signal lights work on a 1974 K10 pickup? I've tried Sylvania and several other brands to no avail. I understand how LEDs work and that the current has to pass thru them in only one direction. Has any body experience the same thing and make them work? If so, what did you do.

Thx for any help.
Dan Brown

 

Did you install load resistors?

 

All load resistors do is stop the hyper flash which isn't my problem. I want to install old style bayonet mount 1157 bulbs and make them work 'plug and play' and not have to worry about swithching the polarity in the light emitting DIODE. I can't understand why Sylvania and others bother to make LED replacement bulbs when they won't work 'plug and play'.

 

They could make polarity independent LED replacement bulbs, but you wouldn't pay for them because they would be cost prohibitive. It is the DIODE part of the LED that is prohibiting the backwards flow of electricity as compared with a filament bulb which can handle current in both directions and work perfectly fine. It is this very fundamental design element of incandescent bulbs that the circuit designers utilized in your truck and many others like it through the years that makes LED replacements incompatible. It isn't so much the fault of bulb manufacturers as they are making a bulb that functionally fits & in most cases works. It was the auto manufacturer that played tricks with the electrical circuit flip-flopping power/ground signals making LED bulbs incompatible.

 

I fully understand all the diode talk you mentioned. What I really fail to understand is why Sylvania makes the LED 1157 bulbs and don't tell you on the package that 'THEY WON'T WORK ON OLDER VEHICLES', so why make them at all? I've talked to Sylvania about this and was told that their ZEVO brand 1157s would work. Bought some, and guess what, no worky. One option I'm considering is to change the sockets to the new style which use, I think it's 3157 bulbs, so if it doesn't work the first time I install it I just turn it around and reinstall it and it'll work.