trailer running lights problem

[wil.hansen]

paul, what did you eventually do to fix the problem?

the connection to the TV where the circuit protector connects to the car's running lights, seems legit.

[parnold]

In my case I soldered the connection to the TV running light circuit. I had a splice connector in there, it would read voltage on a meter, and ever power my LED tester, but when actually connected to the trailer, the current draw was too much and the connection failed. It drove me crazy for hours.

[dh]

That 'box' is a relay, (they call it a circuit protector because it protects the vehicle circuits by isolating them from the trailer circits) It has +12v, ground, RT/S, LT/S and marker light wires comming from the vehicle and RT/S, LT/S and marker light wirign going to the trailer plug (powered from the +12v wire) It has power going into it, but not comming out on the marker light leg. So, either it was installed without a fuse, on the +12v or the fuse was too large. My bet is when you shorted the marker light circuit, you fried the contactors.

[bobhenry]

That 'box' is a relay, (they call it a circuit protector because it protects the vehicle circuits by isolating them from the trailer circits) It has +12v, ground, RT/S, LT/S and marker light wires comming from the vehicle and RT/S, LT/S and marker light wirign going to the trailer plug (powered from the +12v wire) It has power going into it, but not comming out on the marker light leg. So, either it was installed without a fuse, on the +12v or the fuse was too large. My bet is when you shorted the marker light circuit, you fried the contactors.

I am guessing the tow vehicle has amber turn signals and the magic box is a converter box. These little boogers are real sensative and fry at the drop of a hat generally a short or overload. You have no recourse but to replace it.

[Dale M.]

That 'box' is a relay, (they call it a circuit protector because it protects the vehicle circuits by isolating them from the trailer circits) It has +12v, ground, RT/S, LT/S and marker light wires comming from the vehicle and RT/S, LT/S and marker light wirign going to the trailer plug (powered from the +12v wire) It has power going into it, but not comming out on the marker light leg. So, either it was installed without a fuse, on the +12v or the fuse was too large. My bet is when you shorted the marker light circuit, you fried the contactors.

Actually its not only a "circuit protector" as stated on box it is a "light converter" for stop/turn signal conversion for three filament (multiple bulb system) to two filament bulb system (trailer).... It does not contain any (mechanical) relays or fuses, it is a "solid state" (component) system and they tend to go "PHEEEET" and quit working when something shorts out or just for the heck of it.... I have "smoked" several because the are just not up to the job.....

Though tail (lamp) circuit should not have any conversion inside box (should be straight through) it still may have a problem inside box.... Check with meter that you have 12 volts going into box on tail lamp circuit and on other side (trailer) for 12 volts ( use pin trick to pierce wire)....

Dale

[wil.hansen]

i really want to just splice and bypass the box. will that present all sorts of problems? don't really want to drop the money/time to pick another one up and install the whole damn thing.

[Dale M.]

i really want to just splice and bypass the box. will that present all sorts of problems? don't really want to drop the money/time to pick another one up and install the whole damn thing.

For tail lamps (and clearance) you can probably do that (at least try it).... But you need "box" for stop and turn signal function...

Dale

[Nobody]

i really want to just splice and bypass the box. will that present all sorts of problems? don't really want to drop the money/time to pick another one up and install the whole damn thing.

Yep, it'll present problems unless your trailer has separate brake (stop) & turn signal lights.

You'll notice on your REESE 'Circuit Protector/Converter' that there are 5 wires going into the 'CAR' end, & 4 wires coming out of the 'TRAILER' end. Your tow vehicle obviously has separate turn signal lights & brake lights so these must be 'combined' in the converter in order to work your trailer lights which normally use a single bulb/filament for the stop/turn signals.

IF your trailer already has separate turn/stop lights then you MAY be able to bypass the protector/converter but, many late model vehicles have on-board computer systems for the electrical/electronics that may also be damaged if you bypass the protector/converter.

If you have power going into the protector/converter thru the 'TAIL' wire, & no power coming out the 'TRAILER' side of the 'TAIL' wire, you should replace the module before doing anything else.

As said by other posters, those little units are FRAGILE (both physically & electronically) & it don't take much to 'fry' 'em. Generic modules aren't terribly expensive but sometimes they're kinda 'proud' of brand name units. I've not observed much difference in durability between either kind.

[dh]

I couldn't read the lables on my cell phone
The tail lights do not pass through the box, as stated, it protects the vehicle circuits by seperating them from trailer circuits. If you bypass the box with the tail light circuit and start blowing fuses on the tail light circuit, you may have to add a relay.

[dh]

If you want to add a layer of protection to the two remaining circuits on the converter/protecter, just run those circuits on relays as well, so all the current that will ever go through the box is what it takes to trip the relay. You already have a 12v+ wire there so it would be easy. I'd also find where that 'hot' wire originates and make sure it has a fuse in it.

[Engineer Guy]

'Dale' and 'Nobody' hit the proverbial Nail on the head in terms of what's needed. Non-negotiable in my experience: you need the Converter Box.

It is extremely unlikely that there are any Relays in the Box you had, and that the desired outcome could be achieved using Relays.

What's in the Box are 'blocking Diodes'. They allow current to flow one direction [to the Trailer Lamps], but not 'back' to the Tow Vehicle. As 'Nobody' notes, most modern Vehicle circuitry has changed to where it's not as straightforward as it used to be. For example, integral Burglar Alarms look for slight voltage drops when Doors are opened and Dome Lights illuminate. That's done with 'subtle' Electronics. This ain't your Father's Oldsmobile, as the old TV Ad goes...

Blocking Diodes allow current from 2 Vehicle Lamps to connect; flow into; and illuminate one Trailer Lamp. Then, it can serve 2 functions using one Lamp Filament.

Also, other dead giveaways provide confirmation. Blocking Diodes can be potted into a lil square package. Relays typically cannot. There are very compact, sealed package Relays - used in applications like Coffee Pots - but Diodes are much cheaper.

When I put on my own OEM Converter Box - I didn't muck with trying to make my own, even though this ex-Ham has all the know-how - the Harness was plug-n-play compatible to the Vehicle Lighting Harness. My Montero Sport is a 2000, and yet even those 'ancient', >11-year-old Electronics needed a Converter Box to then wire out to a Trailer.

Sorry for this news, but there's no shortcuts I know of that prevent getting and installing another Converter Box. What 'Nobody' said twice...

As mentioned above, I would first verify Trailer Lights and Ground independently, and only THEN connect the Converter Box. To quote A. Einstein [paraphrased], 'insanity is repeating the same actions while expecting different results'.

[angib]

I have "smoked" several because the are just not up to the job.....

I guess you guys just don't have access to proper auto electrical supply shops like we do in Britain or you would be able to reuse these converters once you had added some replacement smoke. The quality of the smoke matters - be sure to use only the manufacturers own smoke:

[Nobody]

I have "smoked" several because the are just not up to the job.....

I guess you guys just don't have access to proper auto electrical supply shops like we do in Britain or you would be able to reuse these converters once you had added some replacement smoke. The quality of the smoke matters - be sure to use only the manufacturers own smoke:

Right Andrew; & failure to get the 'correct' smoke will probably void yer 're-smoked' converter warranty - Seriously wil.hansen, with all the little electronic 'gizzies' in today's vehicles depending on computer direction/control, I'd not take a chance on 'screwing' something up by bypassing that box.

[wil.hansen]

i went the safe (and time consuming/expensive) route and bought a new converter box/wiring. Installed the whole thing myself in a couple of hours. Everything works perfectly and the peace of mind and satisfaction was worth the time/money. Thanks for all the help everyone!
-w

[eamarquardt]

I have "smoked" several because the are just not up to the job.....

I guess you guys just don't have access to proper auto electrical supply shops like we do in Britain or you would be able to reuse these converters once you had added some replacement smoke. The quality of the smoke matters - be sure to use only the manufacturers own smoke:

Here, on this side of the pond, Lucas Automotive Stuff (LAS) doesn't have all that fine a reputation for being reliable, the availability of replacement smoke notwithstanding. On a Triumph Bonneville, I once switched from Low Beam to High Beam but got No Beam. Given that I was on a dark canyon road with a two hundred foot drop on one side, there were a few "tense moments". I've never been enamored with Lucas stuff since.

My Ford van has a system on it to detect burned out bulbs. The bulbs are hot all the time and the ground is switched to turn them on. If 12V isn't detected on the ground side of the bulb when the bulb is off (as in a burned out filament) a warning light is triggered (but it doesn't tell you the exact bulb). This precludes directly connecting the trailer lights to the van's lights and required a special harness, black box, relay, and separate 12V supply to drive a trailer's lights.

Cheers,

Gus