Left Turn Signal and Rear Running Lights Out

[jak2998]

So, I just spent the day trying to troubleshoot why the rear running lights and left turn signal won't work on our 2020 New Aire, Freightliner chassis. I swapped the LH and RH tail light harnesses and had the same issue, so pretty sure it isn't the tail light harnesses. Checked all the bulbs, so that isn't it.
Hooked up toad and LH and RH turn signals worked, but no running lights on it either. Brake lights and reverse lights all work on the RV. I disconnected the tail light harnesses to the chassis harness and sprayed it with contact cleaner. At first LH tail light was only showing about 3 volts, while RH showed 13+. When I checked voltage on running lights it checked good.
So, I put everything back together and at least so far it is working. I am worried, however, there is a bad connection or relay or something upstream that will crap out again.
Also, I could not find turn signal relays. They are not in the fwd LH compartment and rear RH only has relays for the toad. Anyone have any ideas where they are, or suggestions for the problem I described?

[outlawten5]

PDM recall? Is the dash A/C working?

[shepardmike]

When I have experienced this in the past it's usually been a bad ground. I would start tracing down the ground wires.

[Rd1]

Originally Posted by jak2998

............2020 New Aire, Freightliner chassis. ..................

tail lights issue is a known problem with frieghtliners going back to 2016/17 and continue thru at least 2020 models;

https://www.nhtsa.gov/vehicle/2020/N...20AIRE#recalls

look under;
Damaged Circuit Board May Affect Lighting Function

[SeeAmerica]

Power Distribution Module recall by Freightliner.