Well, We have had about 5 inches of rain recently and my truck had to sit in it, when I got in I noticed a little water on the Passenger side floor mat. Anyone have an idea on the source, is this a common problem? I have cab lights, would it be coming from one of those? If so, which one or all, and is there an easy fix?

Thanks.

 

The evaporator drain may be plugged.
It is the rubber drain on the engine side of the firewall.
Pinch it open and maybe stick a pencil into it.
It is common in humid rainny days where you run the air a lot.

 

Thanks I will check that, but the truck hasn't moved in a week it has been sitting in the rain. Its used to being in the Garage.

 

Check the third tail light at top of cab. It is common leak point and runs down back of cab and forward. Mine is due again for a new gasket.

 

any coolant smell?

 

No, is this a common problem? I am guessing you are going for a heater core. The truck hasn't been driven in a couple of weeks, it is leaking sitting still.