Diesal starting problem in humid weather

MY 2004 Dodge 5.9l Cummins as a starting issue when the temp and humidity get about 85. If I park the vehicle east into the sun, it has a more frequent problem.



I have taken the truck to the dealer 3 times and it always starts but I don’t think they parked it facing east. All the computer analysis are normal



Any solutions? They are stumped

If there is a relay of some sort under the dashboard it could be overheating in the sun and not functioning properly. Otherwise the direction in which you park the truck should not matter.

Hondas of a certain vintage have this problem, it’s a fuel pump relay, and when the vehicle is parked in the sun the interior gets hot, the relay doesn’t work, and it prevents the engine from getting fuel.

Thanks, I will pass that along to the dealer

I would check the battery cables. If they are having a little problem making a good solid contact the damp weather might be just enough to put them over the top.