we had a lot of rain over the past two days. i got water coming in on passenger side drain plug for the sunroof. it has happened before i thought i fixed it by adding longer hose to piece the dealer only had one piece so i put it on the driver side the hard side. well i got most of the water dry i never had a problem before. i went to start the car and the traction control and abs lights were blinking. i let it run for a few mins. after that i turned the car off and it won't power anything anymore. my control doesn't unlock the door or lock. it's like if it were completely dead. battery is good, the fuses are good, i did disconnect the bcm the top right connecter had about 5 drop of water when i blew them off with air. it's connector with three wires. i saw a relay that pwm relay (next to battery) not sure how to test it but i was going to replace it. any ideas what it could be? what i should test?

 

Probably blew the fusible link, it's the positive battery connection, there are all the primary system high amp fuses in it.

Firstly disconnect the battery, take out the BCM and put it in a bag of rice to dry out like how you would fix a cell phone that got dunked. Overnight in the rice is fine, this will give you time to fix the cabin water leak.

While the battery is disconnected inspect the fusible link, pretty sure you'll find one of the half-dozen or so fuses on it is blown up, buy a new fusible link holder if you can't find the individual fuses, they should come stacked with all the fuses and they're like $25 at Autozone for a new one.

The sunroof drain usually clogs up where it dumps into the cowl, you can remove the cowl cover and use a pipe cleaner to pull debris out from the cowl side, easier than taking apart interior components to get to that side of the hose.

 

just double checked the big fuse link the 80a 100a there were four on mine they look to be good, not broke or discolor. i ordered a new drain plug for passenger side for sunroof. i have the bcm in rice right now. i also removed the fuse box next to battery but that seems to be good not wet. i'm almost thinking it fried the bcm... you have to get the same part number right? i have someone removing one tomorrow to check part number.

 

Yeah the BCM is an exact part number replacement. It also requires programming from Nissan/Infiniti because it holds all the NATS/IVIS stuff. Typically it's just a 1 hour service charge for the programming, you schedule the time, tow the vehicle to their parking lot, they program, you drive away.

 

was about to go buy the part for fuses on battery but i tested voltage all come back good on voltage. i took out the bcm from the rice after letting it sit for two days and put everything back together and still car is completely dead... any ideas?

 

Check the ground connection from your negative battery terminal and the grounding points on the engine and body. Corrosion on the connections and broken ground wires are common issues in all cars.

 

When you say "completely dead" you mean the headlights don't turn on, no brake lights, no HORN, no dash lights, no nothing right?

Put the battery on a charger and see what it will do, or try it in another vehicle, just because you measure voltage doesn't mean it has any amperage to push those electrons.

If the car is actually completely dead but you still don't have things like HORN which are not part of the BCM then you have other problems going on with power delivery.

 

^^^^

Water damage may very well finished off an old marginal battery?
The op mentions the battery is good without mentioning its age or how he determined it is good. No mention of using a multi meter or battery hydrometer or using a load tester

Felepe 86

Obtain a battery hydrometer and a multi meter to do your troubleshooting


Let us know what you find out? You may also have a failed IPDM?
Follow troubleshooting in the FSM

 

yes it was completely dead no horn or nothing. update so i took out the battery out of my other car put it in and it started right up. ran it for couple seconds saw smoke, weird smell from the alternator. the dash light were starting to come on again, abs, brake light, air bag, i turned it off and unplugged the battery about to remove alternator to get it tested. saw that there was some oil on alternator from power steering pump leaking little fluid. i put the battery in my other car that was in the g35 and it barely had any juice to turn on the dash lights. i'll go get it tested too it's only a year old maybe it can be charged.

 

Sounds very likely that a power steering leak onto the alternator is causing the alternator to fail. It's a fairly sensitive electrical component that doesn't like being juiced with oil or water. Pretty much everything under the hood of a car has sensitive electronics under it thus why manufacturers use undercarriage splash plates now to protect all the electronic components.

 

good news got it all fixed up. never seen that before but now that i think about it haven't really seen a alternator that low in that area. from cars that i have owned or worked on they are usually up top. so short caused battery to go dead. was able to get it charged and tested it turned out good. got alternator and power steering pump on. everything else back together. running like a champ. thanks for the help!

also noticed the valve cover is starting to leak so going to tackle that next week. what are the oem spark plugs that are on vehicle? i tried to look for them a while back because i wanted to replace them but i was finding that they should be good for long time. i'm at 156k miles pretty sure original plugs got car used had 46k miles.