running lights issues on '72 Ambassador

[72Ambassador]

Ok here is the deal, we have break lights when the break is applied of course, both blinkers, and hazard lights. No running lights. So we checked to 7 pin round plug that was bad, so we went and purchased and installed a new round 7 pin OEM plug we are getting 12v to the left and right blinker. 12v to another blade that I would think is the blade for the running lights. If we take one of the blades for the blinkers and but the running lights wire to it the running lights blink. When we place the wire on the 12v blade that we think is the running lights nothing, we have taken a meter to it and it gets 12v and yet nothing, not even blinkers work on that one leg. I am almost sure it’s a ground some where but not sure where to look. I know there is a ground on the tong of the trailer. but I am still mind boggled as to where and what I am missing to correct the problem, and I need to get this figured out before this weekend, setting up my Hunting camp and the lights are the only thing keeping her road ready. Anyone have any ideas????? And of course the backing lights have been completely removed from the trailer so once I get this problem settled then I can install and figure out how I am going to wire them in.
thanks for any help you all might have

[azflycaster]

Different years have different pin assignments for the lights and brakes in the trailers. Make sure that you are wired correctly for you year. here is the plug arrangement for the 70's

[Lumatic]

Originally Posted by azflycaster

Different years have different pin assignments for the lights and brakes in the trailers. Make sure that you are wired correctly for you year. here is the plug arrangement for the 70's

Ditto

The easiest place to switch the wiring around is at the 7 way access panel inside the coach in front of the gaucho. You could also rewire either umbilical plug or the TV. In newer tow vehicles and trailers the wiring is based on an industry standard and they are all the same.

Has anybody asked for pictures yet? We love pictures.

[arodriguez60]

Check the ground at the running lights. Take off the lenses and touch where the bulb goes into the socket with your probe from your voltmeter if the light turns on clean the sockets on the lights and the bulbs. (clean of the corrosion) Bad grounds and loose connections are the most commen problems in 12 volt systems

[ROBERTSUNRUS]

Hi, check the wiring in the seven wire connections on both the tow vehicle and trailer. Make sure the tow vehicle connector has power at the correct pin for running lights. [check tow vehicle trailer lights fuses] And finally, if you running lights blink when connected to a turn signal wire, you don't have a ground problem. If you had a ground problem they wouldn't work at all.

[72Ambassador]

I guess what we just can't wrap are head around is the fact that with the meter we are getting 12v on both blinker and the running lights post/plug where the green wire is suppost to connect into the trailer plug under the window behind the sofa at the tong, but when we hook up the green wire nothing is what we get. When we take the green wire and put it on the right or left turn signals post they do blink. we are getting 12v the meter backs that up(and we are not using a cheap walmart or auto zone meter so i know the meter is ture) but how can you get 12v and the green wire is working on the other post but just not when you hook it up where it needs to be???? that is what we are having a problem understanding.

thanks for all your help so far i hope you all can answer that one. You know what they say a fresh pair of eyes will find what you could all day long.

happy travels

[richinny]

i would try to identify the wires on the trailer umbilical first. the wiring may have already been upgraded and the colors may not be correct. find your hot wire and your ground. the ground will have continuity to the frame. then put a jumper from the hot to the tail and signal lights to identify them. one of the wires goes to the electric brakes and will not light up anything :-)

[faceter548]

My 78 has fuses for the tralier lights on the 12 distribution panel in the trailer,not sure if yous does

Jim

[astewart]

'72. It is common to see 12V on the far side of a load that isn't grounded but when you connect it to a ground it disapears. Stated another way, if you run 12V to one side of a light, both side will show 12V to ground until you connect the ground side of the light (then it shows 0v).

Wish it was clearer but that may be the issue you are seeing.

Good luck,
Alex