So I have a 98 ram I've owned 3 of them and have installed radios in all of them normally a 1/2 hour process and done. Well I had the one in my current truck for about a week before the tuner decided not to work. (it was a free well used junk jensen radio so I didn't expect much) but the cd player still worked so I just used that for the next 3 months. So the other day got in my truck turned it on and nothing. I thought it was done for so I got a new radio switch the adapters and still nothing. I had a test light out clipped it to the ground wire and have power through the red wire all the way through the wiring adapter and at the plug that goes into the radio. Now the yellow wire I don't. Should I? Besides the red power wire the ground and the yellow wire. the rest are all speaker wires correct? And I also don't have the infinity sound so no amps or anything to worry about.

 

Its been a while but you should ave 12v on both red and yellow and both should be used. Red is a switched 12v I think and yellow is a constant 12v

 

Thats what i thought but wasnt sure. Now to figure out why im not getting the constant power i need

 

You are correct yellow is constant