• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR5/TR250 Problem Hooking up trailer lights in the TR250

Share this page

Got_All_4

Got_All_4

Luke Skywalker
Country flag
Offline
Going to the Roadster Factor Party next week and hooking up trailer lights to the small utility trailer I pull with camping gear. Problem is that I can't get full power to the trailer turnsignal lights with out pulling the terminals for the bulbs for the car. With running lights on you can't see the trailer bulbs flashing. I have cleaned every connection several times along with grounds. Check grounds with my OEM meter with the same results.
Interstate battery is 1 month old. alternator is 50 amp Bosch so plenty of power to push through. At wits end.
PS
I hate trailer wiring!!
 
Easy check, do the turn signals on the car fade out with the trailer connected? If not, the problem has to be the trailer or the wiring to it.

What are you doing for the 3 filament to 2 filament conversion? Triumphs use two separate bulbs for turn signals and brake lights (3 filaments counting tail lights); while every trailer I've ever seen wants to use the same filament for brake and turn. There is no way to just wire them together and have all the lights work properly, you have to either add lamps to the trailer or use an active converter box.

Keep in mind that turn signals draw a fair amount of current. A bad connection may pass enough current to let your voltmeter show 12 volts with nothing connected, but not enough to run the turn signals, etc. You'll get a much clearer picture if you test with the bulbs connected.
 
I did use a 4 wire to a 3 wire converter. In fact it is the same one that I use in my Tr3 and 7 in past years. I just used quick connects/disconnects and swap the pig tail between cars. This is the first year pulling a trailer with the 250. With that being said I think I kinda did what you suggested Randall? I pulled the solid green wire that goes to the tail light fixture from the harness coupler so no steeling of current, so it goes directly to the trailer. The results were that the trailer lights were much brighter then the car alone. Back to the TR3. It has a much weaker electrical system although dimmer lights there was a noticeable difference in the brightness of the designated flashes.
I think I'm going to pull the flasher from the TR3 (I think it is heavy duty) and give that a try. If it works then I'll go to parts store and get one. If not back to the brain storming.
 
Yep that fixed it. However walking out to the 3 I was thinking it is a 3 wire flasher and that's correct. Just went to the parts store and bought an electronic one that has circuit boards in it for $11. Installed it and a nice consistent flash and i can hear the clicks too. Although there is something about that lazy flash of the originals. This is a nice change though. With the trailer lights facing the sun you can't miss the signal. Thanks Andrew and all that chimed in.
 
Back
Top