Alright guys, I've got a 1991 Cherokee 4.0 and AW4 auto. I know you're all probably thinking this is another case that could easily be solved by Google and a little reading. Unfortunately I've tried that with no success.

Last night my Jeep ran fine then overnight we had a massive rainstorm. I go out to start it today and it just cranks. The fuel pump isn't priming so I throw a new relay in along with a new ASD relay. Still nothing. In addition to all this when I flip the key on the auxiliary fan turns on. My check engine light also turns on so I tried the key trick, the key trick isn't working so I can't get any codes from it. My first instinct says something got wet, what are the components I should check? (Its not the NSS or CPS, already checked those too.) I'm thinking that maybe water got to the computer and toasted it. Thanks for any help guys.

 

Not likely, have you disassembled and checked the bulkhead connector?

 

Do you mean the C-101 connector? Mine doesn't have that one. Or is the bulkhead connector the big plug on the back of the fusebox? I haven't cleaned that one yet. I removed the PCM and cleaned the connector and was going to inspect the circuit board but its covered in a gel to waterproof it I guess. I had figured that the PCM was bad because the check engine light wouldn't flash any codes (Which seemed computer related) and since its mounted on the fender water could've gotten to it. Of course I could be going down the wrong path though

 

There's currently a snowstorm outside so I can't check the bulkhead connector yet. I'm sure regardless of whether or not its the problem it should be cleaned. The PCM doesn't seem to have gotten any water in it so I guess that's probably not it. Definitely some weird symptoms! Thanks for the bulkhead suggestion Turbo, when it clears up I'll get right out there and give it a clean

 

Checked the starter connections and the airbox/intake? You could always rip out the spark plugs and make sure they didnt get some extra corrosion from the moisture.

 

any time you turn the key on with engine off the check engine light will be on, it doesn't mean you have any codes, if it stays on once the engine starts then you have codes stored in the pcm. when the engine is cranking does the tach gauge(rpms) move at all? that should indicate that the crank sensor is operating correctly.

 

Starter connections, intake and spark plugs are fine. I know about the check engine light, it stays on it so theres a code I just can't access it for some reason. I've got spark, the gauges all move. The reason I had believed that the PCM was shot is because I can't access the codes giving the check engine light and the moment I turn the key on my auxiliary fan starts up. We just had a snowstorm so I still haven't had the chance to pull out the fuse block and clean the connector.