logic circuit help with tail lights

[Woodbutcher]

I am asking this question in referance to the thread below. Its the one that says "trailer blinker lights" .I started it a long time ago and am just now doing the lights. Since I got no replies I thought I'd try a new thread........


Well I don't know if this is the oldest reply to a past post, but I am on Teardrop time. I am nearing the end of my build. I followed Sonetpro's diagram as best I could. I can not get the logic circuit do break up the 2 lights into stop and blinker.

Right now I have all running lights working. I have the 2 black tail light leads (on each side)connected to the brown wire from the harness. The yellow to the 2 red leads on the tail lights (they are the stop/turn wire out of the tail light). With the running lights on, everything lights up including all 4 tail lights. When the blinkers are on, both lights on each side blink. This is where the problem is. I want only 1 of the 2 lights to blink, leaving 3 brake lights on with 1 blinking tail light. I have had no luck with the logic circuits at all. I can't tell if the brake light works while the blinkers are on. I am doing this alone and trying to see everything in a mirror hanging on my garage door.

Can anyone offer any help? Next trip is to DMV I hope. Thanks in advance.

[Dale M.]

Keep it simple.... Only have two brake lights, one on each side and two blinkers one on each side....

IF you want anything else you need some electronic magic... Maybe something as simple as a couple or relays to BLINK turn signal element while other lamps stay on (brake).... Only problem with relay is lamp will not be powered to blink when brakes are off... ( you are only using blinker circuit to operate relay with this concept)

Other scheme may be to use out side bulbs as blinker /stop using using 3 element to two element converter box available most any where and run separate brake light only circuit from tow vehicle to illuminate "inside" bulbs... Only problem wiring gets complicated and will be incompatable to any tow vehicle other than the one you have specifically wired to work this way...

Dale

[bobhenry]

One man trailer brake light check ....

Equipment needed 1 old yardstick

optional equipment 2 couch cushions

Depress break pedal with hand place end of yardstick on pedal
depress back of seat and place other end against seat back
if yardstick is a bit short place couch cushions as needed to maintain pressure on brake pedal.

[Alphacarina]

Using the brake lights (or 4 way flashers) to connect trailer lights can still leave you with grief when you try the turn signals - The left and right side brake lights are not the same and need to be wired to the correct light on each side of the car

If the 'running lights' are working, then attach the wire for the low wattage filament of your tail lights (the tail light wire) to the running lights on each side and you should have tail lights

The remaining wire from the 'tail light' is for the brake light and turn signal filament and you need to find that connection with the blinker on . . . . not the 4 way flasher or the brake lights. Get the left side working and then move to the right side and when your trailer lights blink with your blinker lights, then your 4 way flashers will work . . . . automatically

Two (or 3 or 4) tail lights per side is no problem - Add them in parallel to the ones you now have working and they will work fine too

Don

[bobhenry]

You have indicated your lights have 2 red and 1 black lead.
This indicates to me that the black is a dedicated ground and the 2 reds are turn and tail. ground the black wire and take a jumper wire and touch each red to the 12 volts 1 at a time . The brighter light is your turn/brake elements.

You have not told us what you are towing with if it has seperate turn and brake lights you will need a converter box.

Rewire with the black as ground the 2 less brite reds should be coupled with the brown harness wire the green to the right turn and the yellow to the left turn. ( This is providing your tow vehicle is wired standard)

And if it still don't work let us know we will guess again

[bobhenry]

Went back to old thread sorry I jumped in before I looked at it.

You want what I'm trying to do. I'm mounting a brake light only , in the center of the hatch door about 42" high. In order to do this without it blinking when either turn is on you have to bring in a seperate brake hot wire. I have not done it yet but the switch above the brake pedal makes a 12 volt connection only when the pedal is depressed. I intend to feed off of the down side of this switch ( only hot when pedal is depressed ) and run a seperate circuit to the center brake light.

I'd just run a wire from the switch back to the light and see. I'd just lay it in the grass and if it works then go to the trouble to route it thru the harness.

[brian_bp]

...I'm mounting a brake light only , in the center of the hatch door about 42" high. In order to do this without it blinking when either turn is on you have to bring in a seperate brake hot wire. I have not done it yet but the switch above the brake pedal makes a 12 volt connection only when the pedal is depressed. I intend to feed off of the down side of this switch ( only hot when pedal is depressed ) and run a seperate circuit to the center brake light...

This may seem obvious, but recent Jeeps should have a Center High Mounted Stop Lamp (CHMSL, or "third brake light") of their own. Rather than getting into the brake switch wiring, I would tap off of that, since it's exactly what you want to duplicate on the trailer. If the Jeep is old enough to not have a CHMSL, or they are still not used in the U.S., I would look at a newer (or Canadian) Jeep to see if it is practical to get the parts to build it in properly.

At least use a relay, if tapping into the brake switch wiring.

[Woodbutcher]

Each of the 4 (LED units) have 3 wires ...Black says Tail the white wire says ground and the red wire says tail/stop. The only way I have been able to get this to work leaves me with both lights on each side blinking. What I was trying to do was get 3 brake lights and 1 blinker. I have 2 logic circuits that were recommended in my old thread. But they don't do anything. Any Ideas? I hope I have made it a little clearer. This is not my strong suit.

[Dale M.]

Solution already posted...

Going left to right on back of trailer

Lamp "A" brake light/tune signal work through standard "converter".
Lamb "B" works on separate stop lamp circuit from tow vehicle (same circuit as lamp "C"). Maybe tap on CHMSL

Lamp "C" works on separate stop lamp circuit from tow vehicle (same circuit as lamp "B". Maybe tap on CHMSL
Lamp "D" brake light/tune signal work through standard "converter".

All 4 "tail lamps" tie common and are not issue....

Dale

[Woodbutcher]

Thanks, I'll try it again. If I understand what you are saying the logic circuit is inline on one stop/turn wire on 1 light. The directions on the logic circuit says yellow wire to left light, green wire to right light , and the blue to third brake light. Are you saying to run the leed wire into the yellow wire through the logic circuit and out the green wire to the start/stop wire into the light? Sorry to be a pain but this confuses me.

Thanks in advance.
Steve

[Dale M.]

Not knowing exactly which logic circuit you are using wire logic circuit as per instructions for SINGLE tail lamp application on trailer (one on each side) lets call then bulbs A&D....

Simply wire second pair of STOP lamps (one on each side) to "third brake light" circuit. Probably NOT taking them through any logic circuit, just wire direct from vehicle wiring. These will be tagged as B&C

You are simple creating two separate stop light circuits ...

You need to divorce operation of lamps A & D from operation of B&C and wire each set separately ...





Dale

[Woodbutcher]

Thanks Dale very much! One last question , what does HCMSL mean in the diagram? I promise this will be the last question.

Steve

[Micro469]

Thanks Dale very much! One last question , what does HCMSL mean in the diagram? I promise this will be the last question.

Steve

HCMSL=CHMSL Center High Mounted Stop Light

[Dale M.]

Thanks Dale very much! One last question , what does HCMSL mean in the diagram? I promise this will be the last question.

Steve

HCMSL=CHMSL Center High Mounted Stop Light

Yep...Twisted the acronym around a bit in senior moment...

Dale

[Woodbutcher]

Thanks Dale....I got it.