Whelen ssfpos high side flasher issue


Original poster
May 21, 2010
Trying to troubleshoot a problem. I have this flasher installed on my pickup. I had it installed on my old pickup as well, no issues. The only difference is I installed aftermarket LED bulbs, versus the factory halogen on the old truck.

Now, after activating either the brights or the flasher, positive power seems to be creeping thru the wiring and the bulbs stay lit, albeit, at a lower intensity. The only way to get them to turn off is to pull the flasher plug or the fuse for the flasher.

Would installing something like turn signal resistors fix this? Or is there something inline to install to each bulb? Or some other electrical wiring feat??



Junior Member
Aug 22, 2013
Ok - don't laugh at me too much, but I work on cb & ham radios from time to time and saw a "similar" problem with a cb radio where they install LED's and the channel display glows when the power is shut off because LED's are so energy efficient. The cb glowing issue was caused because the power switch on that cb is turned on/off through the ground instead of the hot wire which allows a small amount of current to flow even when it's turned off, causing the glow. One repair video I saw, the cb repairman used a 12 volt relay to solve the issue. The relay will shut off the power and of course, turn it back on later when it's turned on.
I'm not saying this is the correct way (or will even work for this) but it reminded me of it so thought I would comment. I will try to link the cb repair video below, but if you have free time to watch it maybe it will help give you an idea on how to fix your light?
Also in this video the cb repairman talks about using resistors, but in this cb radio scenario a person would have to use a good sized resistor, like 5 watt, because a resistor can get hot so thought that might be helpful to bring up, too, since you mentioned resistors. I don't know if this will help or give you any ideas, but I'm hoping it does!

The video link is:
Hopefully someone will know the correct way to fix the issue, but do hope this gives you an idea or two to consider.



Original poster
May 21, 2010
Thanks for the info. But, I don't know that that will work here.

I tried wiring this in both manners below, the isolated and non-isolated (with diodes attached to the factory wiring to prevent backwards power feed). As, the high beams in the isolated manner, as I wanted it installed, then get their power from the flasher power and the white wire, hooked to the factory switch, simply turns them on. Cut the power with a relay, no power for brights. When I hooked it up in the non-isolated manner, same result. So, power is trickling thru from the main power wire of the flasher, as when other wires were disconnected, the lights still stayed on.
I was able to overcome this, at least temporarily, by wiring this, in the non-isolated fashion, both the power wire and flasher turn on to the switch, thus cutting the power to the flasher when it wasn't turned on, while maintaining the ability to turn on the brights with the factory switch.

Ideally, I'd like to wire this in the designated manner, but might just have to live with this as I have it now.

Whelen HLF.JPG

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