After an engine swap I got a Battery not charging message. I checked the wires to the alternator and found I did not plug in the two wire connector that goes to the alternator. The heavy wire from the starter was connected. . I plugged the two wire connector into the back of the alternator , thought my problem would be solved. However the message and light on the gauge stayed on. Did I damage the alternator not having the wires plugged in? Its a new battery, could that be the problem or is the alternator bad. It worked good before the engine change. Thanks

 

Check fuse number 2 on the drivers side under the hood.

 

I checked the number two fuse, the generator regulator fuse and it was OK. Not blown. Thanks

 

Leaving that connector unplugged should not have hurt anything as its just the sense line to the dash/gauge.


Dave

 

To remove the engine requires possibly destroying main chassis ground 1 point strap, as there is no real way to remove it.

This is the strap that was bolted to the tranny to the frame, on the passenger side. I would jack the car up and inspect this strap if you continue to get this message

 

Thanks, I did check the ground strap. It is attached.

 

If you've got a voltmeter, I'd recommend a voltage measurement at the alternator, with the car running of course. 13.x volts would be about right.

If that's what shows up then we've got a good alternator, but an instrumentation problem.

[edit] Oops, forgot. The voltage gauge on the dash ... is it reading something like 12 volts, or is it pinned on the left, as though there was no voltage?

 

The big wire from the alternator goes to the megafuse box in the trunk. You can measure the voltage there and also make sure that fuse is still good. Also the alternator may be putting out the right voltage but the circuit for the sense wires in the alternator may be bad as I have seen that happen before.


Dave

 

You know what, I forget to mention, after you plug the wires back in,remove the negative battery cable in trunk,touch it to the positive battery TERMINAL for 30 seconds.

Then reconnect it.


The computer in the trunk sensed a open circuit and closed it off from the system.

 

Thanks everybody. Today I changed batteries, thinking that I might have a bad battery. No help. When I turn on the key the voltmeter on the dash shows around 10 to 11 volts. When I start the car the voltmeter goes to 13 volts, the red light stays on and I get the battery not charging message. I would think 13 volts while running would put the light out, but it does not. I will try hooking the neg and pos cables together to get a fresh start. Once again thanks everyone.

 

Here are the two schematics involved, in case you need to check some wires, it might be the case you have a low resistance short drawing juice away but not enough to trip a fuse.

 

Does anyone know at what voltage the red light in the amp gauge goes out and the battery not charging message goes away. With my engine running I am showing 13 plus amps.

 

Have you tried reseating the sense wires on the alternator? That is where the gauge and dash get their info.
And it is possible for the alternator to fail in such a way to be putting out the correct voltage but not sending the correct signal to the dash.


Dave

 

Good idea. The plug is a bear to get out. Maybe it's a bear to get back in properly.

Putting some silicone lube on the outside surface of the connector helps because
otherwise the connector hangs against some sharp corners.

11 volts seems low on a fresh battery with key on only. It should hold at somewhere
north of 12.5 volts.

Even if the connection is good, the red light signals a multitude of conditions in a
Denso regulator.

My money is on seating the plug fully.

 

That voltage gauge gives pretty crude (but not useless) readings. 13 volts is what my car shows, engine on. No red light. 12 volts is a normal reading engine off, dropping down to about 10 while the starter is engaged.

I agree, your 11 volts engine-off seems low. Not sure what to make of that at this point.

If re-seating the connector does not do the trick, it's really worth investing in a voltmeter to go further. Suggested measurements:
- DC voltages on the alternator "big wire" ... engine-off and engine-on
- Same DC voltages on the connector
- AC voltages (really) at both spots, only engine-on needed.

Good luck!