Wiring of Trailer Lights

cullig_jp

I intend to wire my friends trailer lights for him. I know its a 7 pin plug. Is there anybody who has done this previously and would they have any tips for me?

seamus_mcg

here is the pin layout

CJhaughey

Once you have made all your connections smear Vaseline over all the terminals to prevent corrosion.

Stoner

seamus_mcg wrote: »

here is the pin layout

thats one for the circuit diagram sticky!

enmac

use a metal connector - Dogs love to chew on the plastic ones

35x

Just needed a wiring diag and checked posts....great diag, thanks a million seamus mcg for making my task straightforward!!!

mazthespark

solder everything! when i re wired my trailer i ran cable to each light and back to a junction box mounted under the chassis because i have marker lights and spots on the ladder rack for night work etc which come on with rear fog light switch. from there i also went to a trailer socket mounted on front of trailer and have a lead with a plug on both ends from this to the socket on vehicle because generally this part gets most of the abuse. all my joints were stripped and soldered and heat shrinked and where i had spade terminals or anything i soldered them after i crimped them. i know it seems like over kill but its never given me any problems to this day.

Davy

mazthespark wrote: »

i also went to a trailer socket mounted on front of trailer and have a lead with a plug on both ends from this to the socket on vehicle because generally this part gets most of the abuse.

Defo the best way to do it. Very few trailers seem to come this way but its the best job.

Ive been over and back with the plastic versus metal plug top. The metal seem to get brittle over time and crack, while the plastic take a fair bit of abuse. The one thing i found with a plastic one lately, the rim on the inside that holds the termination plate in place, got bent out of shape and then it was becoming loose or staying in the socket when removed. Very annoying

M cebee

would it not be 'plug to socket' flexible lead

and a fixed plug on the trailer

mazthespark

just used what i had available at the time depends on your setup etc doesnt really make a huge difference to the operation or the idea

M cebee

suppose it's alright for 12v
small risk of blowing a fuse if you're careless with the end of plug

mazthespark

but one end will be left affixed to the trailer unless it has a fault and then you just replace it the only reason for the plug/socket arrangement on the trailer is to make it easier to fix when it breaks

M cebee

ya

just my electrical training kicks-in when i hear 'plug to plug'

suppose it doesn't matter that much

mazthespark

so does mine i know its not correct in electrical terms but its only a trailer and its 12v so not a huge sin really and tryin to get the rite parts to do it correctly if they even exist could be a pain.

nowimtalkin

Found this thread while trying to wire a 7 pin plug.
However, my problem now goes further than the plug. All of the wires are corroded, at first I tried to clean them but to no avail. I then cut them back at least a foot and they are still corroded. At this stage, I cannot afford to cut the wires any more as the plug will not reach the back of the towing vehicle if I do.

Has anyone any suggestions?

I have no idea how much more of the wires are corroded. Should I just rewire it completely?

For cleaning, I have used a wirebrush, sandpaper, baking soda and toothbrushes! I'm not sure how much these cleaning methods would be recommended, but I have no idea how to do any more with it.

All suggestions greatly appreciated

mazthespark

could u mount a plug on the trailer and make up a lead to go from trailer to the vehicle?

Davy

mazthespark wrote: »

could u mount a plug on the trailer and make up a lead to go from trailer to the vehicle?

It sounds so bad, i would redo the whole lot. It will be one less connection point to fail

mazthespark

i re wired mine 3 years ago and have a plug at front of trailer and a connection box which everything comes back to soldered everything tho! and have never had any problems except with the lamps. most trailers are done that way now as the cable from trailer to vehicle always gets chewed up eventually

dasheriff

nowimtalkin wrote: »

Found this thread while trying to wire a 7 pin plug.
However, my problem now goes further than the plug. All of the wires are corroded, at first I tried to clean them but to no avail. I then cut them back at least a foot and they are still corroded. At this stage, I cannot afford to cut the wires any more as the plug will not reach the back of the towing vehicle if I do.

Has anyone any suggestions?

I have no idea how much more of the wires are corroded. Should I just rewire it completely?

For cleaning, I have used a wirebrush, sandpaper, baking soda and toothbrushes! I'm not sure how much these cleaning methods would be recommended, but I have no idea how to do any more with it.

All suggestions greatly appreciated

I would strongly recomend that you rewire it all it will only be causing you probs forever more..

Buford T Justice

+1 on the re-wire,

You'll forever have trouble with it the way it is if its in bad shape. Do it right and do it once I say.

35x

Very interesting idea which won a prize in the new inventions competition at Tullamore Show recently - wireless trailer lights- there is some fitting which goes in the car/van/tractor and transmits to lighting board. It seem a great idea and was done by a company called 'Prisma' I think

clark2334

mazthespark wrote:
i re wired mine 3 years ago and have a plug at front of boat trailer lights and a connection box which everything comes back to soldered everything tho! and have never had any problems except with the lamps. most trailers are done that way now as the cable from trailer to vehicle always gets chewed up eventually

I also did that re-wiring. We should always remember that we can get any trailer lights working, when we know what wire does what. This Trailer Wiring Diagram and Color Chart helped em a lot to do the right wiring connection:

http://autorepair.about.com/od/fixityourself/ss/trailer-wiring_3.htm

Anthonyk2010

I'm after replacing the wiring on my trailer lights and i have hit a couple of problems.
The indicators are the first problem, one minute they work the next minute nothing. I stuck a screwdriver inbetween the bulb and the termanels and they work fine,when i remove it bulb stop blinking

Could this be a ground problem or is the bulb unit finished.

Next the brake light dont work at all, no idea why.

I have checked all the wiring and it looks fine but i'm not sure how it test if there is power coming through.

Can it be done with a multimeter?

Why is there no neutral wire, how is the circuit complete

Buford T Justice

Anthonyk2010 wrote: »

I'm after replacing the wiring on my trailer lights and i have hit a couple of problems.
The indicators are the first problem, one minute they work the next minute nothing. I stuck a screwdriver inbetween the bulb and the termanels and they work fine,when i remove it bulb stop blinking

Could this be a ground problem or is the bulb unit finished.

Next the brake light dont work at all, no idea why.

I have checked all the wiring and it looks fine but i'm not sure how it test if there is power coming through.

Can it be done with a multimeter?

Why is there no neutral wire, how is the circuit complete

Yes, you can use a multimeter, checking either for 12V DC or continuity. There is a negative on the lights, but there is only one and its common to all lights. Look at the inside of the light fitting, there should be a single strip of metal going to the sides of all the bulbs, that's you're negative.

Bruthal

mazthespark wrote: »

solder everything! when i re wired my trailer i ran cable to each light and back to a junction box mounted under the chassis because i have marker lights and spots on the ladder rack for night work etc which come on with rear fog light switch. from there i also went to a trailer socket mounted on front of trailer and have a lead with a plug on both ends from this to the socket on vehicle because generally this part gets most of the abuse. all my joints were stripped and soldered and heat shrinked and where i had spade terminals or anything i soldered them after i crimped them. i know it seems like over kill but its never given me any problems to this day.

No overkill there in my opinion anyway, even some car manufacturers dont make great grounding connections onto cars for lights, as can be seen when the various lights are feeding through each other when a common ground connection for several lights fails.

aujopimur

When I had vans I always put the socket inside the back of the van, it cut down on faults with dirty & broken plugs & sockets.

brownswiss

seamus_mcg wrote: »

here is the pin layout

.


Indicators are working on my trailers but parking lights are not working.

connections on plugs seem fine. have tried 2 trailers and same thing.

I there a fuse and if so is it a seperate fuse for parking and indicators.

Al lights are working on car..


Thanks

mazthespark

check the connections from the trailer socket to the car. usually made at the back of a light cluster or on modern cars there is a small control box sometimes its usually located in the same sort of area. mite be a dodgy connection there or at the plug on the back of car. can u check trailers on a known working vehicle just to be sure about trailers also maybe

micosoft

Having a spot of bother with a trailer light set. Put a new connector on and everything works except brake lights. It uses combo light bulbs (brake/side lights) - if you put the bulbs in one way the side lights work perfectly (half bulb lit) but brake does not work when pressed. if you turn the bulb the other way the whole bulb lights (even without the brake being applied). I've checked the wiring again and it seems to work. I need to grab a multimeter to test but does anyone have any ideas? Presuming sidelight works at 5v and brakes light on 12v or how do the combo bulbs work?

Bruthal

micosoft wrote: »

Having a spot of bother with a trailer light set. Put a new connector on and everything works except brake lights. It uses combo light bulbs (brake/side lights) - if you put the bulbs in one way the side lights work perfectly (half bulb lit) but brake does not work when pressed. if you turn the bulb the other way the whole bulb lights (even without the brake being applied). I've checked the wiring again and it seems to work. I need to grab a multimeter to test but does anyone have any ideas? Presuming sidelight works at 5v and brakes light on 12v or how do the combo bulbs work?

You possibly have the 0v (ground) mixed up with one of the 12v switched wires, (from the brake pedal switch and sidelight switch)

The 0v should be onto the metal part of the bulb, and then the brakes 12v and side lights 12v should each be to a contact on the bottom of the bulb.

With 0v going to one of the bottom contacts, the effect you are seeing will be the result.