gallilaw

I have posted frequently about a stubborn current drain problem that has gone on for months. New batteries would drain dead, and apparently would not charge even when new (rebuilt) alternators were installed. I put in three batteries and three alternators and no there was no change other than I spent a lot of money.

Recently I traced a large standby current drain going through the B terminal of the alternator: when the S terminal wire was powered (as it must be) 270 mA of parasitic current leaked through the main charging wire to the B terminal, and the car never went into sleep mode, so the total standby current draw was 330 mA.

The Nissan dealer and a local shop had both been stumped, made bad assumptions and threw parts at the problem. I spent a lot of time on this forum getting advice and trying out solutions. I finally took the car to a well-regarded auto electric specialty shop. It took them less than two hours to diagnose a frankly unbelievable cause:

Inside the plastic connector that plugs into the alternator, someone had swapped the position of the two wires that went to the S and L terminals!

As soon as the electric shop returned the wires to their proper positions in the connector, the 270 mA current draw disappeared and the car went into sleep mode as it should.

Obviously, no one who has worked on the car during the last few months will admit having switched the wires. I have my suspicions, but can't prove them.

I might still have some problems to solve -- it will take a while to reconnect everything I took off line while researching my issue -- but from my own experience and from scouring this forum I have learned a couple of lessons:

1. When the dealer or anyone else replaces some major electrical equipment, make sure you get the old equipment back. You might need to prove there was nothing wrong with it.

2. Don't let anyone put a device like an alternator in your car without knowing in advance the manufacturer, make and model number to ensure that it will fit without modifying the system it's going into.

3. When you have an alternator problem, unless it's under warranty don't go to a dealer -- go to a reputable auto electric shop. The same thing goes for parasitic current drains whatever the cause.