← vanagon.com home · Continue the discussion in the forum
VanagonEuroVan
Sort by authorSort by posting dateSort by topicChronological orderMost recent firstShow authorHide authorShow table of contentsHide table of contentsBack to main VANAGON pageJoin or leave VANAGONSearch
Subject:Re: Resistor for LED turn signal
From:David Beierl <dbeierl@GMAIL.COM>
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
> >
>

← Previous in thread
Back to August 2019, week 4
Have something to add on this topic today? Revive this thread in the forum »