no brake lites or hazard but turn signals flicker

ajriding wrote:

A multi-meter will only tell you voltage, so checking all connections will not tell you if it is getting a good flow of that 12 volts, which is also called amps.

Truth. The way around this is to use a test lamp rather than a voltmeter. If there's not enough current, the lamp will show it.

thank you all for the good ideas i will pursue

This will happen if the lights are not getting the full 12 volts. Which is often a ground problem. LEDs will work as you described, some lights illuminate a little bit, maybe flicker, and others, like brake, will do nothing.
A multi-meter will only tell you voltage, so checking all connections will not tell you if it is getting a good flow of that 12 volts, which is also called amps.

Check from the vehicle that you get power to all the trailer plug connections.
Check that your trailer plug is not corroded. The 7-pin plugs get a lot of green "rust-looking" mess on it. scrape that off. Use vinegar to help. Disconnect from the camper battery, then dip it in the vinegar, let sit, then use toothbrush or something to clean it.

I prevent this corrosion to a large extent by using a circuit breaker so I can disconnect the 12V positive from the camper battery to the 7-pin plug. This way there is no electrical potential in the moist air around the plug. a 12v positive so close to a 12v negative.

I think the Freightliner chassis has one flasher for turn signals, and a different flasher for the hazards.

Suggest you call the Freightliner help desk...a free service. They can give you some advice on the location of the flasher(s) and maybe help in troubleshooting your problem.

Have the last 6 digits of your vin number when you call as they will ask for that to find the records on your chassis.

1-800-FTL-HELP

There is also a Freightliner Chassis forum on the IRV2 site that may be able to help.

Fred

The third brake light (light bar in this case) works off circuit that feeds anti-lock brakes.
OP:
There could be a connector at the base of the steering wheel that could be pulled loose.

I would guess that light bar is LED so can still work with a very weak ground.

The higher wattage incandescent lamps can't work correctly with the bad ground.

Have you located the flasher?
Have you checked the turn signal flasher fuse?
A poor electrical connection in the power lead. Check voltage at brake light socket.
Are the brake /turn signals LED?

grounds grounds grounds TT TC class A or cc

First thought is a ground, because you report that the turn signals flicker. Also no brake lights doesn't sound like the flasher.

Even CARS have too many grounding problems with rear lighting.

Motorhomes are a festival of nightmares with rear lighting. And a large majority are chassis negative issues.