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Technical Using a trailer wire converter "relay" for use with a 3 wire turn signal switch?

Discussion in 'The Hokey Ass Message Board' started by F&J, Sep 12, 2016.

  1. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    I'm having problems trying to use on of those electronic adapters that lets you use a trailer with only 2 filaments per side, on a car that has separate wires for brake, RT and Left.

    That would be just like my build which has a separate wire for brake, and one for right turn and one for left signal, but using only two filaments per side...like a trailer

    I hooked up the car exactly by the writing on the unit. I've got brake wire going in, r and l going in, and tail going in, and a ground wire properly grounded.

    The other end only has 4 wires out. One for tail, one ground, on R and one L, just like what I need for my twin 41 chevy lights.

    I only get taillights working.

    Yes I have new bulb contacts, new wires, and I verified the grounds are good and sockets/bulbs are good, as I can feed 12v to each taillight pigtail and get them to work, both tail and bright filaments, and both work, even both at once by jumping both pigtails

    There is no power coming out of this converter on R or L wires. I jumped the brake switch and see 12v at the input but nothing coming out. Also set T/S switch to each side and have power going in, but nothing coming out.

    Ok, defective converter? I already took one back to A-zone, got the same unit, same results. So I just got one from NAPA, same Hopkins brand, but this one has the flat 4 wire output plug attached. The AZ ones have no plug, just wires to splice.

    Weird thing: If I set TS to one side and leave brakes off, then put a test light on that side's TS wire, the rear light does have the bright filament working, Why does it take a bit of resistance to do that?

    But just trying brakes alone, I can use test light and neither brake filament works

    What am I doing wrong here?
     
  2. Are you using LED or non-standard lamps? You may not have enough current flow to let the convertor work....
     
  3. Hnstray
    Joined: Aug 23, 2009
    Posts: 10,602

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    By chance, I have just installed two of theses converter units within the past few days. One each on a couple of my OT vehicles. It sounds like you have the converter connected correctly.

    Nevertheless....on my vehicles the wiring for the individual lights is....White/ground.....yellow/turn....green/turn.....brown/taillights......red/brake lights

    output is.....white/ground.....yellow/turn&brake.....green/turn&brake......brown/taillights

    On one vehicle it was a new installation. No issues getting it working. The other was necessitated when I was renting a trailer this weekend and could not get the left signal/brake light on the trailer to function correctly. The towing vehicle worked fine. Close examination revealed a burned/melted spot of the OE converter. I bought a new Hopkins at O'Reilly's, cut out the old one, wired in the new one and it functioned fine.

    I can't imagine you are getting a series of bad converters, though I suppose anything is possible. But my guess is there is an as yet undetected glitch in your wiring or cross connected wires or a bulb with filaments touching internally, etc., etc.....something is amiss. At this point you can't take anything for granted. I'd begin again by separating the vehicle harness from the converter and testing each circuit individually......then do the same with the trailer wiring.......

    Ray
     
  4. tim troutman
    Joined: Aug 6, 2012
    Posts: 187

    tim troutman
    Member

    those trailer converters will only work on negative ground systems I have one on my 40 12volt had to wire a1156 bulb in the dash on both sides to get it to work
     
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  5. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    The converter says do not exceed 2.1 amp per side, and says only trailer with 2 taillights...not more

    All I have for bulbs on the back is 1034 dual filaments...one per side..no front signals wired yet

    I just came back in after trying things...

    I disconnected the R and L inputs to the converter, but have tail and brake inputs hooked up. I jumped BL switch. Then a VOM on the outputs for R and L which show 12v but bulbs are still off !...but when I use a test light on the disconnected inputs for R and L, the test light stays off, but the tail light bulb comes on strong, when test-lighting either side...either bulb then works.

    So is the converter needing some resistance? on the R and L?

    The reason I decided to disconnect R and L input: This vintage TS switch has 3 wires. One in from flasher, the two (for R and L sides). But it has a mini-bulb indicator lamp built in, that comes on in R or L position but off when centered. I took the mini bulb out, no change on the problem, but I suspect some odd way in the switch to have the lamp work? I mentioned a few days ago that I did not know how an indicator can do that on a 3 wire TS

    so, do I need to take the TS apart to disable some contact, if that is the problem? I just checked the R and L disconnected wires going into the trunk from TS. When TS is centered, I still show .o2 V and each wire

    I am thinking the converter won't work unless all inputs are hooked up, and no random trace voltage coming from TS?
     
  6. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    Ray and Tim; I tried putting more lamp load on the ouputs, but it did nothing.

    see my last post about my TS switch. Might be the issue?
     
  7. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    Just a thought? If the brakelight will work if I use that testlight "upstream" but the testlight stays off as it does do...

    Should I stop right now, and wire the front signal bulbs first? That would give the same effect as using the test light, right?
     
  8. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    Well, hooking up my miniature front signal bulbs R and L, that are 4.6 watt number 1893, makes the signal circuits work, as well as both brake lights. Who knows why the signal bulbs in the front need to be hooked up to make the BRAKE lights work??

    But it works. And if a signal bulb ever burns out up front, one of my brake lights will go out too. Not very safe IMO.

    My last question is a flasher that will trip with one rear 1034 and one mini bulb up front on each side?
    Has to be either super light duty, or can I use the electronic flasher on this type of system with a converter? I tried a few normal 2 prong flashers I had, and they won't trip, due to low draw
     
    Last edited: Sep 12, 2016
  9. What converter are you using?

    I hooked one of these up with an old signal switch and it worked flawlessly.
    Took me a few mins to get my bearings with it though- getting it into my schematic and theirs. Once that happened I was off- like a prom dress.
     
  10. image.jpeg

    I put it mid car, flat 4 connector to the rear lights bulbs
     
  11. Those electronic boxes can be picky about what's hooked to them, I wish I could explain what's going on but I can't.. Hey, it's working...
    You should be able to use a 'any load' electronic flasher, I've used one with this type setup before.
     
  12. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    It's working now, after realizing that there has to be signals up front, for resistance for the converter to work. Brakes and signals won't work without that, as I found out later today

    Hopefully if other rodders use one, they will remember that you must have either "front" signals to make it work.. If you don't want front signals, then you must at least have separate R and L dash indicators, which also give enough resistance for the converter to work..

    Who knew?.. not me, until today
     
  13. Seem to remember reading that internal circuitry of the converter box "grounds" out thru the opposite side bulb (on the car side of the converter), that's why once you added the front lights it worked.
     
  14. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    I know very little about electronics, but the converter box has a dedicated white ground input and a white ground output to trailer plug, but it might be just a wire passing through the box, just like the taillight wire?

    It just seems odd that the brakes won't work either, if the car has no front signals or dash lamps

    If this was used as intended on a towing car, that car has at least 3 resisting bulbs per side: Front and rear bulbs plus dash indicator. So, all 3 would need to be burned out to have no lights working on the trailer
     
  15. What converter are you using ?
     
  16. Hnstray
    Joined: Aug 23, 2009
    Posts: 10,602

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    Frank, are you certain your trailer lights have a good ground path from the bulb hold through the trailer frame an into the white ground wire connection?

    Ray
     
  17. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    Hopkins label from Autozone and the other one was Napa labeled Hopkins with a flat 4 term trailer connector, but same box
    Ray, I'm unsure if you read where it is fixed now, or if you missed the part where this is not being used for a trailer; it is for my hotrod that has a 3-wire T/S switch that normally won't work with a two filament-per-side system. The converter allows use of the old 3 wire T/S, to keep the old taillights that only have two contacts.

    I never would have been able to trace the problem with a VOM. By using the test light, it's bulb supplied the resistance needed for the electronics when I tested "upstream" from the converter. As soon as I tested there, the test light did not glow, but the bright filament on that side taillight lit up. It baffled me for awhile, then realized that if the test light stayed off, but gave resistance, that would be the same as if I had hooked up the front signals "before" I tried the converter. It would have worked if I had, but I was wiring the back of the car first.
     
  18. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    In case other people are not understanding why a converter is needed with a 3 wire turn signal switch, on a car that only has two filaments per side on the rear lights:

    -here is a pic of the 3 wire type and also the 7 wire type switches:
    DSCN0686.JPG

    ^ the older 3 wire type does not have a brake feed wire, and does not have a LF, LR, RF, and RR wires. It only has an input from flasher, and a R wire and L wire.

    These older styles were used for adding signals to a car/truck that never had them, but it required adding another single filament light on each corner of the car/truck.

    On an old time rod or custom, we don't want to add more light assembly's, so if you want the look of an old TS switch, you need the converter.

    If you don't mind the modern look of the repro 7 wire TS, then it can use your old 2 contact taillights without need for a converter.....because the brake feeds into it, and uses the same wire going to RR or LR for both the brakes and the signal.
     
  19. H380
    Joined: Sep 20, 2015
    Posts: 402

    H380
    Member
    from Louisiana

    Absolutely check the white ground wire on the trailer plug. Without that ground on the trailer side the lights will not work at all. I had a friend with a '96 T100 Toyota that needed the box to use trailer lights (Toyota branded box and wiring kit). Actually most of the older Japanese vehicles with amber tail lights need the box. My and all of my friends US trucks had no problem with my trailer. That damn T100 HAD to have the white ground wire attached to the trailer frame. Any US truck the lights work without the trailer ground.
     
  20. Maybe try 1157 bulbs, the 2 prong flasher on my '35 will flash with only the rear lights connected.
     
  21. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    Yes, it has ground wires and they were connected; if you read back a few posts, the issue was resolved,

    I need to get a "new" flasher, rather than these used ones. I did find one that works with the small load of a 1034 and a front miniature bulb, but it needs to stay illuminated a bit longer each time it flashes. That is because my tiny front signals really need brightness. The bulb is somewhat not fully glowing by the time the flasher kicks off each cycle. I tried a #55 bulb up front by mistake and it was 6v...that was really bright but I bet it won't last.

    I'll find something local. Just trying to get good lights for the other drivers not looking/paying attention. It's hard with tiny front and rear lights we rodders use. Oh well.
     
  22. d2_willys
    Joined: Sep 8, 2007
    Posts: 4,094

    d2_willys
    Member
    from Kansas

    Guess what, I work for Hopkins and the tow converters are my responsibility. What you have is the non powered converter. It needs to have turn signals and brake lights to be incandescent bulbs. This converter will NOT work with LEDS. The converter electronics depends on having grounds thru the bulbs. When brakes are off, the brake light takes care of left or right turn signal electronics getting a ground. When turn signal is off, the turn signal (right or left) supplies the brake light signal electronics ground. We do sell a non powered unit that is compatible with LED turn signals. #48895.
    On newer cars the wiring is so small that the body control module cannot supply more than 1 or 2 loads out of each output. For anything new, the converter is always a "powered" unit.

    Hope this helps.

    Matt F.
     
  23. Hnstray
    Joined: Aug 23, 2009
    Posts: 10,602

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    Matt,

    Thank you very much for that explanation. Of the two converters I installed this past week, one was on my late model DD and was a powered converter......the first I have ever seen. I installed it per directions and, of course, it worked fine. But wondered WHY it was powered.
    Now I know the reason and it will help when choosing a converter in the future for other vehicles!

    Ray
     
  24. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    Wow, that's cool, but I wish you were here when I was messed up :)

    Here is another update that might help if someone was trouble shooting a rod/custom with this box. I was hooking up all my front lights today. You know how most of us hook one headlight or park light, we test it before starting other lights?

    Well, I hooked up the real front signal lamp on drivers side. Tried the signal switch...and the front did blink but nothing on the driver rear...WTH. So I figured it must need the passenger lamp to be hooked up, even though common sense says you are not using that side to test the driver side.

    I used a test light on the passenger side.. the switch on driver side. Now the driver rear and driver front work, but going to pass side the rear was on but the test light was off WTH again.

    Do not do this shi..t when you are tired, or don't have every lamp hooked up properly LOL

    So, if the RT front bulb burns out, and you make a Left turn, the left rear will be out !

    Can you imagine diagnosing a car with this system? We are using a part that is not designed for use in a car, it is made for a trailer, so I'm not complaining. It just would be a nightmare to figure out, unless you remembered this thread? In other words, if the LR signal bulb was not working, who on earth would go test the opposite front bulb to see if it is burned out? Nobody :)

    I'm taking a coffee break first!..then hooking up the real passenger front lamp....and I'm hoping everything finally works

    EDIT: I did get every front and rear light hooked up permanently, and did all the tests like signals by themselves, then signal with brakes on, and then headlights on, brakes on, and signal on, and it all works fine now.
     
    Last edited: Sep 13, 2016
    Hnstray likes this.
  25. d2_willys
    Joined: Sep 8, 2007
    Posts: 4,094

    d2_willys
    Member
    from Kansas


    Next time use Hopkins 48895 or a powered converter. Both have the necessary grounding circuitry and should install much easier.
     
    F&J likes this.
  26. tb33anda3rd
    Joined: Oct 8, 2010
    Posts: 15,008

    tb33anda3rd
    ALLIANCE MEMBER
    1. Connecticut HAMB'ers

    Frank, i wonder if the future "diagnosing problem" would be resolved by adding another two bulbs [side markers or indicators] to the system?
     
  27. F&J
    Joined: Apr 5, 2007
    Posts: 13,177

    F&J
    ALLIANCE MEMBER

    or, in hindsight, If I knew what D2-willys said about the other unit, I would have tried to find one.

    I am shocked that the local stores only had the type for not-so-modern cars? That seems odd, as most people would be getting one for a new car?

    It still works fine though. I do have a huge picture window at the front of the shop, and as I drive by at the angle of the driveway, I can see all my lights in the reflection, each time I take it out.
     
  28. Krash Vegas
    Joined: Jul 18, 2006
    Posts: 437

    Krash Vegas
    Member
    from Dallas TX

    This is the one I used on my Mercury.
    Its pretty simple.

    s-l500.jpg
     

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