2014 Big Horn - Struggling with LED pod foglight power/flickering

[Mechatricity]

I've gone several rounds with my LED pod foglight retrofit trying to supply clean power. The foglights are not monitored by the BCM with a bulb out strategy, so i first assumed i could use foglight power directly. This resulted in a very faint but noticeable erratic flickering from the LED pods. I assumed the foglights have some PWM control strategy and the LED pods didn't like that.

So for round two, i moved to a relay triggered from one of the foglight positive leads and the LEDs powered directly from the battery. Much to my surprise the flickering got even worse, although only when the truck was running. I started probing around with my multimeter and noticed that the + side of the foglight (my relay trigger) sees battery voltage (~12.3v or whatever) when key ON engine OFF, but as soon as i start the truck, the voltage on that leg drops to ~10v. This appears to be right at the lower limit of the trigger input voltage for the relay, resulting in the relay firing on and off as the voltage fluctuates around 10v.

So ultimately i guess my question is, is there a default strategy in the BCM that drops the voltage to the foglights if the foglight circuit isn't complete? i'm wondering if i tied in the foglight ground into the relay ground if that would resolve the issue as the BCM should see a complete foglight circuit in that case. I'm really trying to avoid having to switch these manually when there is a perfectly good foglight switch in the cab.

Thanks!

 

[Spud2388]

Try adding a canbus module or anti flicker module on each light and see what happens. They're pretty cheap on Amazon and definitely worth a shot. What kind or relay did you use by chance? The normal Bosch relays sold at the local auto parts store should trigger well below 10v I would think.

 

[Mechatricity]

Try adding a canbus module or anti flicker module on each light and see what happens. They're pretty cheap on Amazon and definitely worth a shot. What kind or relay did you use by chance? The normal Bosch relays sold at the local auto parts store should trigger well below 10v I would think.

Thanks for the response. Yeah these are standard Bosch style relays, just some random brand from amazon that had good reviews. If i were still powering the pods directly from foglight power i would consider adding canbus modules, but it would be a lot of work to go back to that configuration now, so i'm going to continue to try to figure out why the foglight circuit is behaving like it is. I'm going to try plugging in a foglight bulb (connectors are still in place) and see if completing the circuit changes the behavior.

 

[magician]

It’s my thought that the BCM is monitoring the current draw and when it either gets to high or to low it drops the output for circuit protection. I’ve seen this on a work truck we were outfitting with lights and radios. Actually saw a Chevy have to be towed when he keyed his radio with all the strobes and beacon lights on. In any case, an unused keyed on 12 podcast source should clean everything up for you. Good luck.