1964 Trailer wiring HELP

mike107, Jan 26, 8:36am
Hi, Thanks in advance. Has One red light on back, Lights up when brake is put on (all good). Lights up when car headlights are on (all good). BUT when car lights on and trailer tail light is on and then car brake is applied it goes off, this is the problem. What could it be!

jono2912, Jan 26, 8:44am
Does the bulb in the red light have one or two filaments!

mike107, Jan 26, 8:46am
Plastic Lense has one small bulb that also does number plate light and a larger bulb. (TWO single filament bulbs).

mike107, Jan 26, 8:48am
Trailer plug had Black (Earth) and two red wires. No. 7 Tail (red) and No 6. Brakes.(Red)

jono2912, Jan 26, 8:52am
Okay, just backtracking for a sec, does the trailer have a separate stop and a separate park light! Or are they just the one light! If so, does the one light have a bulb with two filaments! Or have a misinterpreted.

mike107, Jan 26, 8:56am
One Round plastic lense with a clear part in the side, under this cover there is TWO single filament bulbs. Smaller bulb is nearest the clear part on the side for a number plate light, then a larger single filament bulb in the middle. Thanks.

jono2912, Jan 26, 9:02am
Ah okay, and that light acts as #plate, park and stop! in that case, there would need to be 3 bulbs. or 2 bulbs, one with double filaments.

I will now apologise in advance if I'm getting this wrong, I'm more of a pictorial person.

wrackman, Jan 26, 9:04am
Sounds like this is just a stop-tail lamp
Unit has a bad earth,try middle pin of trailer plug to see if pin has a air gap through the middle of it

mike107, Jan 26, 9:15am
Yes just a stop tail lamp unit with Number plate hole (clear part in red).
How do I test the middle pin! Thanks.

mike107, Jan 26, 9:17am
Air Gap as in the split gap in pin!

jono2912, Jan 26, 9:25am
Far out, I get it now. hahaha.

bigfatmat1, Jan 26, 9:38am
spread it with a fine screwdriver so the contact is firm between the plugs. if that fails Your problem is a bad earth. somewherecheck the wire on the rear lamp and check to make sure the connector is not loose on the earth rail of the lamp check to make sure you have a earth on the vehicle side of things put a test light accross pin 3 and 7 turn ya park lights on and make sure it lights up

mike107, Jan 26, 9:41am
Thanks Big mat! I will try it tomorrow!

mike107, Jan 29, 6:40am
All fixed, it was a bad earth.

lookoutas, Feb 16, 4:50pm
Sorry - hadn't seen this before.
Bad earth was the only answer.