

| Subject: | Re: Resistor for LED turn signal |
| From: | David Beierl |
| Date: | Tue, 27 Aug 2019 02:14:58 -0400 |
An 1156 or 1157 lamp is 27 watts, and the running light filament in the 1157 is about 8 watts. We know that if the 1157 is reversed in the front turn signal, the resulting ~35 watt load is not enough to put the flasher in slow-flash mode. If you want to pretend to be a pair of 27 watt lamps you will have to dissipate 56 watts of power, which is your give or take 2R5 resistor. Undoubtedly you could get away with a higher value, as the flasher threshold is somewhere between 35 watts and 56 watts. And of course you get to subtract the actual draw of the LED lamps which helps a bit. This is a power circuit and simply doesn't notice resistance in the hundreds of ohms. Yrs, d On Mon, Aug 26, 2019 at 10:38 PM Richard Koerner <rjkinpb@sbcglobal.net> wrote: > David...do you mean more like 2.5 Kohms instead of 2.5 Ohms for the inline > resistors? Otherwise, I am confused. > > > > On Monday, August 26, 2019, 7:16:02 PM PDT, David Beierl < > dbeierl@GMAIL.COM> wrote: > > > Best to do as Alistair suggests. 470 ohms wouldn't even be noticed -- > you'd need more like 2.5 ohms with a 50 watt or better rating, to simulate > the load of a pair of turn signal lamps. Wouldn't have to be at the > lights, just anywhere in the circuit. > > YRs, > d > > On Sun, Aug 25, 2019 at 4:19 PM Stan Shapiro <mail@stanshapiro.com> wrote: > > > 1977 Baywindow, 2 liter, Fuel Injected. > > > > > > > > I installed new LED bulbs for my parking/brake, backup, and turn signals. > > Lighting is MUCH improved. I even added silver reflective HVAC tape on > > the > > inside of the light boxes. > > > > > > > > All work well, and the turn signals blink rapidly-as I pretty much > > expected > > they would. > > > > > > > > Suggestions on thesamba was to install a 470 ohm resistor to cure the > > rapidly blinking turn signals. What is the easiest way of doing > that?? > > I thought about adding a resistor, inline between a male and female > spade, > > and then patching that in right at the turn signal. I am thinking that > it > > has to be done on both sides? Electrical is not my strong point-and I > > may be totally off base, so don't laugh to hard. > > > > > > > > Any suggestions. > > > > > > > > Thanks > > > > stab > > >
Have something to add on this topic today? Revive this thread in the forum »