So I gave my Jeep a good bath and sprayed some underneath to get some old dirt off. A few days later I noticed it was cranking slower but would eventually start. Now after letting it sit a few days, I have a no start and absolutely no power like the battery is completely drained. New battery by the way as of 6 months ago. I tried jumping it and it turns over REALLY slow and just will not start now. When the jumper cables are attached I have a good battery voltage as soon as I take the jumper cables off it goes dead again absolutely no power. Throws no codes. So I was thinking alternator since it seems like a battery issue and I know they dont like mud or to be sprayed with water but I've read the cps can give similar no start symptoms and they hate water as well. What do you guys think? Just trying to get an idea before I start throwing parts at it. Thanks.

 

Wouldnt think it is the crank sensor causing a drain. Fully charge the battery, check the current draw between the neg and positive, unhook the wires from the alt and see if the drain is still there, if it isnt then its a alt.

 

While waiting for the battery to charge, check the battery cables and connectors too.

 

Got it. I'll do just that, thanks. Picking up a re-manufactured alternator today and seeing if it does the trick. I'll report back.

 

Ended up being the alternator I guess they don't like mud or the do it yourself car washes with the high psi sprayer. Still cranks a little slow, but starts up every time. Didn't take very long and was one of the easier things I've done to the Jeep. Hardest part was getting the old alternator out. The new one slid right in with the help of gravity.