Frustrated by Electrical Fault!!

Indicators work perfectly on my series 2a.

Hooked up to my trailor and indicators stop working. Well striktly speaking they are working but very very dull, as though there isnt enough current?

Have hooked the trailer up to my P38 and everything works perfectly so I dont think problem is on trailer.

Unhook trailer connection and the landy indicators are
perfect again!

Side lights and brake lights on trailer work OK.

I have visually inspected wiring and can't see anysthig wrong.

I am stuck for ideas so all ideas appreciated.

Thnks,
Steve.

check the wiring in the back of the socket on the landy
might find a coroded earth wire or something

Check each of the the connections with a multimeter from where the trailer socket feeds off the loom, probably tucked behind the corner covers in the rear of tub particularly the blacks(earths) and the greens (indicators)

If the indicators on the car and on the trailer are dim, then suspect the indicator relay behind the clocks, an electronic relay is a good idea, they just need an addtional earth connection.

There's any number of possibilities in here; but modern C&U standard, call for a trailer socket with an audiable alert for the indicators, as well as an iluminated 'tell-tale' on the dash.
Most modern cars have the tell-tale in place, and a relay with a load sensor in it so that it lights the tell-tale when the trailer socket is plugged in; older cars dont.
On my 109, I got completely frustrated chasing down dead earths and flaky wiring, and trying to get the trailer socket to work properly; I made two aquesitions; first was a complete new trailer socket 'kit' which included the aidiable warning widget, from my local caravan shop, for about a tenner; second was I went and pulled a 'modern' flasher unit out of an old Montego at a breakers.... needn't be a Montego, could be anything with a trailer symbol in the idiot lamps on the dash-board, but a Montego was convenient for me as I needed a tail gate-for one, so was already pulling bits off it, and as I had one, I also had the Haynes Manual for it with the wiring diagrams to see how it fitted into the circuit.....
Then used that as my model to graft the HD flasher into the LR indicator circuit, added the tow socket kit to the back, with a LONG length of trailer board wire running the length of the chassis, and earth made 'sound' to the bulkhead, where the starter motor is earthed.
& Spliced a short section off that spur up to the rear stop lamps and indicators, by-passing all the old wiring and dodgy earths, to get round their ailing illumination, as well....
Worked for me anyway....
And potted, the advice is, for the effort of fault finding ols electrics; just ditch it and start over, doing it as for a modern car with the bits specced for such.

Electronic flasher units have 3 terminals, 31b goes to earth, and try the other 2 both ways till it works.

Thanks for the guidance guys,

Guess what - with trailer plugged in all three indicatord fail, thats previously OK vehicle front and vehicle rear plus the trailer. Its the same scenario for left and right. Whilst in this condition when I remove indicator bulb from vehicle rear the vehicle front and trailer indicate perfectly; now where's the logic in that! Seems like it'll let me have any 2 out of 3. The fact that they can all work (but not together makes me think it's not an earthing issue.

Trailer is definitely quite old with lights built in rather than a modern trailer board. When I plug trailer into my P38 the trailer warning light on dash does light up - does this give any clues?

Electrics is not my strong point although I have never been this confused. If I put multimeter on vehicle rear indicator (from which trailer is joined into) I get about 14v but when I plug in trailer it drops to about 4v.

Socket appears to be wired ok in the sense that there is continuity of colours.

Any further help most appreciated.

Cheers
Steve

Yeah, the 'load' that the trailer electrics are putting on the landies electrics is to high for the flasher.... you need an HD towing flasher, like the one on your P38.

Go down to your auto electrics place and tell them your story, you'll get a new flasher thingy, you only need an extra wire to earth, you can even get them that sense the fact a trailer is plugged in and bleep to remind you your towing.
I heard some MOT stations check that you have a bleeper, they've never bothered checking any of mine, and I've never had a bleeper.
Or you could just go and rip one off a larger car at a breakers (on a rover 200 its a little green box BEHIND the fusebox to the lower right of the steering wheel), most of them will cope with the extra load of another indicator bulb, some as teffy correctly says have an extra output that brings on a warning light to say your towing, but personally if 'lectrics are not your thing, stick to a simple 3 wire.

Thanks guys,

Maybe I've not lost the plot after all.

I will try get a new flasher thingy - the simpler the better as I dont think I will forget I have a trailer in tow!

Having said that, I cant see the trailer at all when driving - doesntbother me till I reverse - I am normally OK reversing but with the landy I am out of line before I see it!

Cheers,
Steve

Steve Ashworth said:

I dont think I will forget I have a trailer in tow!

Click to expand...

Went to collect a motorbike once, coming home, and approaching a set of very tight bends, passenger asked me what the heck I was doing tapping the brake pedal......
"I've got a chuffing biker right on my bludy.......... Ah! yes..... tow.....bar...... that'll be the one on the trailer...... wont it?"

lol

First time towed a trailer with the landy I honestly thought I had lost it as roads were fairly straight and hadn't seen it for ages.

I pulled up and had a look just to be sure!

I spose this isnt a good time to tell this, I drove one of the works trannys with trailer to a customers, and panicked when I got there and the trailer was missing, only to get on the blower to my irate boss who called me a bellend for taking the wrong tranny, the other tranny plus trailer were still in the yard, I was 19 and fick at the time.

lol.

oh dear, oh dear, oh dear - cant beat that one...

May be I will take earlier advice and make sure my replacement indicator unit has the warning light connections!!!