bg18461

iTrader: (8)

Car: 2002 Maxima, 6 speed manual tranny

Hey guys,

I have a mystery I need a little help with. Last week I was having issues with overheating and I thought I heard a leak behind the manifold so I took it off. While I was back there I decided to change both my valve covers and my spark plugs while I was at it. What i was hearing was a minor air leak from the PCV hose (I replaced this hose as well). The issue ended up being the radiator so I replaced it with a koyo radiator and closed the car back up. Overheating solved.

About two days after I was done my car gave me slow starts, like a dead battery.

I originally thought I left a light on or something so I charged the battery up over night and went to work the next day. Car started fine in the morning and I went to work. Upon starting the car at the end of my day, again slow start like a dead battery.

I went to advance auto to have them check my charging system. They did, and told me the system was not charging. I assumed it was the alternator as this is the original alternator at 180,000 miles. I purchased a new (not rebuilt) . Went through the joys of replacing the alternator and the belt, closed the car back up and started it up. Car was now showing the battery and brake light, though it was not showing it before, but the battery was very dead. I charged the battery up again, started it up and brake and battery light went away.

I checked the voltage with a multimeter and it showed 12 volts at 1k rpm, still not charging. When i shifted the car into any gear other than neutral it would not rev. When i put it in neutral i could rev the engine. These weird issues pointed me to voltage issues again. Since the car could not move I went back to advance auto in a different car with the battery and original alternator to check them both and guess what, the original alternator was good...the battery was bad.

I got a new battery, installed it in the car, and it started fine, it would rev in any gear again and could drive. I placed voltmeter again while idling, still showing 12 volts, not charging. Went back with the car to advance and they confirmed it was not charging, which brought me back to the original charging issue...

So after all that, my question is did I miss something when i put the car back together from removing the manifold? Maybe a ground wire or something...the battery is good, the alternator is good, the fuses are good (10A alternator fuse in engine bay and 120A by the positive battery cable), what could it be? At first I thought it was a coincidence that these issues happened after the valve cover/spark plug project, but now I think they are related...

DennisMik

iTrader: (2)

Normally I would say there is nothing a valve cover job would do to the alternator. The wire harness that goes to the alternator is close, but it comes from the body, it is not routed along the engine.

The 10 amp fuse you checked goes to the small 2 wire connector that plugs into the alternator. This is the yellow/black stripe wire. The other wire goes to the battery light in the instrument cluster. Check that that connector is seated all the way in and locked in, and cannot be pulled out. Also check and see if the wires are seated all the way in the connector, too.

MAXC

iTrader: (7)

Also look into checking the harness that plugs into the alt. sometimes the plug gets burned out and even though it's plugged in, you don't get a good connection. Be sure to check that alt. wire harness good.

bg18461

iTrader: (8)

Well, it appears the harness that plugs into the alternator was the culprit. I measured voltage directly from the alternator across ground and it was about 12.5V. I plugged out the harness, cleaned it with electrical contact cleaner and reseated it again. This time I was just about 14V at the alternator and a little less at the battery. Went to advance auto again to double check and their tests showed everything was functioning normally. Thanks for your help DennisMik $ MAXC, really appreciate it!