Forum: WHALER
  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Trailer Lighting

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Trailer Lighting
otpjam posted 04-12-2008 08:14 PM ET (US)   Profile for otpjam   Send Email to otpjam  
[I] just installed a set of trailer lamps and am having a problem with the way the lamps operate. [I] know everything is hooked up right and everything seems to work correctly until [I] turn the parking light on. [T]he marker lights do work but then when [I] step on the brake they both go off. [I]f [I] run either turn signal they both blink and the marker lights dim with the blink. [A]ny suggestions?
davej14 posted 04-12-2008 08:26 PM ET (US)     Profile for davej14  Send Email to davej14     
What vehicle and year do you have. Did you wire the trailer directly to the existing lights or install a power module? How do you know they are wired correctly?
Chuck Tribolet posted 04-12-2008 11:59 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Probably a bad ground SOMEWHERE. The trailer lights are
grounding through the car's brake lights. When you step
on the brakes the ground path doesn't work any more.

The bad ground could be at the truck, or the trailer.

Dave's questions are good ones -- there are some vehicles with
some quirks.


Chuck

jimh posted 04-13-2008 09:18 AM ET (US)     Profile for jimh  Send Email to jimh     
quote:
...everything seems to work correctly until [I] turn the parking light on.

I am not familiar with parking lamps on a trailer. Generally there are only three circuits of lamps on a trailer: marker lights, left turn, and right turn. They use a common ground. As Chuck suggests, most problems are related to poor grounding.

quote:
[T]he marker lights do work but then when [I] step on the brake they both [i.e. marker and brake lights] go off.

The resistance of the ground connection is high. When you step on the brake pedal, voltage is applied to the brake lamp circuit. This drives up the voltage at the ground connection so high that the other lamps extinguish. Because the off-resistance of an incandescent light bulb is so low, the resistance in the wiring that is supplying the voltage must be correspondingly low, otherwise most of the drop in the applied voltage will not occur across the lamp, but across the high resistance in the wiring. That is what is occurring in your situation.

Chuck Tribolet posted 04-13-2008 08:53 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Jim, he didn't sway the trailer had parking lights, he said
the trailer lights work correctly until he turns the parking
lights on.


Chuck

jimh posted 04-13-2008 09:21 PM ET (US)     Profile for jimh  Send Email to jimh     
Chuck--Go for it, you seem to be able to read him better than me.

Post New Topic  Post Reply
Hop to:


Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.