Stumperific Posted June 12 Share Posted June 12 My computer says "charging system problem detected" and zero volts on the display, but it has a new alternator and a new battery. The alternator has 4 pins but the Reatta only uses the middle two L and F, correct? I have 12.3 volts at the battery with the car off and 12.03V with car running. I have cleaned the battery terminals, cleaned the grounds to the motor and body, plus cleaned the junctions for positive and negative wires. What am I missing? Link to comment Share on other sites More sharing options...
Ronnie Posted June 12 Share Posted June 12 We need some background on the charging problem. Was the battery not being charged the reason you installed the new alternator? Or did the problem start after you replaced the alternator? Any additional info you can give us would be helpful. Don't assume the alternator is good just because it is new. 1 2 Link to comment Share on other sites More sharing options...
Anthony Posted June 12 Share Posted June 12 Don't forget to hook up the positive wire on the back of the generator 1 Link to comment Share on other sites More sharing options...
jon L Posted June 12 Share Posted June 12 I think you should get the correct alternator. 1 1 Link to comment Share on other sites More sharing options...
DAVES89 Posted June 12 Share Posted June 12 I agree with Jon. How did you get the alternator? If it's from a parts store or a salvage yard, tell them you got the wrong one and exchange it for a new one. There are so much electronics and sensors it would be hard to say what your issue is. If it's a "free" alternator it's no longer free. 1 1 Link to comment Share on other sites More sharing options...
Stumperific Posted June 12 Topic Author Share Posted June 12 The alternator was replaced after getting the same message. Autozone tested it and said i had a bad alt. i bought a new one and I put it in. I did hook up the rear wire! A little back history, my engine wires were eaten by some mice. My co worker gave me the car to fix. It was a part of the harness that connect to the injectors and the alternator. I got a new section and spliced it in.. engine ran fine. Charging system has not worked since ive had it Link to comment Share on other sites More sharing options...
Ronnie Posted June 13 Share Posted June 13 Go into the onboard diagnostics (instructions below) and check to see if there are any BCM and report them here. There should be a code stored in the BCM since you are getting an error message on the dash. The code should give a hint about what is causing your problem. The charging system on these cars aren't as simple as most cars. The BCM has some control over the alternators output voltage. I'm thinking your probably have some wires still chewed up, or connected wrong, that go between the alternator and the BCM. Just to rule it out as the problem, I would take the alternator back to AutoZone and have them check it to make sure it is operating properly. Also, have them make certain the alternator you got is the correct one for a Reatta. Reatta Owners Journal - How To Access Diagnostic Codes 1 Link to comment Share on other sites More sharing options...
Stumperific Posted June 13 Topic Author Share Posted June 13 Codes I'm getting: B122 B411 Link to comment Share on other sites More sharing options...
Stumperific Posted June 13 Topic Author Share Posted June 13 I will remove and take back to autozone to check.. I am going to replace the plug into the top of the alternator first. Link to comment Share on other sites More sharing options...
Ronnie Posted June 13 Share Posted June 13 Before doing much you should have the alternator checked to ensure that it good and the correct one. From the FSM: Code B411 is telling your the battery voltage is low. Is the fuel gauge working properly? If not check fuse #1, (Ignition) If the fuse is good go back into diagnostics and look at BCM Date BD50 and read the battery voltage there. Then turn on off electrical components like lights, blower fan, etc.. and see how the voltage is effected. Let us know what you find. Don't worry about code B122 for now. It's not related to the charging problem. Link to comment Share on other sites More sharing options...
Anthony Posted June 13 Share Posted June 13 I would take what the procedure for B411 says with a grain of salt because there are some apparent errors on the pages. In one place it says it's a 15amp circuit, but on the diagram it says 10amp. It also refers to circuits 39 and 139, which don't exist on the BCM circuit list. It does however show a 439 and a 239A on the diagram, which is what I assume it's referring to. Link to comment Share on other sites More sharing options...
Anthony Posted June 13 Share Posted June 13 In addition to L and F, you also need the S terminal. It is connected on the other end to battery positive. The regulator inside the alternator needs that input so it can know what the existing battery voltage is Link to comment Share on other sites More sharing options...
Ronnie Posted June 13 Share Posted June 13 1 hour ago, Anthony said: I would take what the procedure for B411 says with a grain of salt because there are some apparent errors on the pages. In one place it says it's a 15amp circuit, but on the diagram it says 10amp. It also refers to circuits 39 and 139, which don't exist on the BCM circuit list. It does however show a 439 and a 239A on the diagram, which is what I assume it's referring to. So what do you suggest? Link to comment Share on other sites More sharing options...
Stumperific Posted June 14 Topic Author Share Posted June 14 On 6/12/2024 at 10:15 PM, Ronnie said: Before doing much you should have the alternator checked to ensure that it good and the correct one. From the FSM: Code B411 is telling your the battery voltage is low. Is the fuel gauge working properly? If not check fuse #1, (Ignition) If the fuse is good go back into diagnostics and look at BCM Date BD50 and read the battery voltage there. Then turn on off electrical components like lights, blower fan, etc.. and see how the voltage is effected. Let us know what you find. Don't worry about code B122 for now. It's not related to the charging problem. The gas gauge is not working. I will locate fuse 1 and report back. I was getting no voltage off the readout when in gauges mode. Link to comment Share on other sites More sharing options...
Ronnie Posted June 16 Share Posted June 16 On 6/12/2024 at 10:15 PM, Ronnie said: Before doing much you should have the alternator checked to ensure that it good and the correct one. On 6/12/2024 at 9:43 PM, Stumperific said: I will remove and take back to autozone to check.. I am going to replace the plug into the top of the alternator first. I see on Facebook where you wrote your alternator tested bad. It would have been nice if you came back here to let us know. Link to comment Share on other sites More sharing options...
Stumperific Posted June 20 Topic Author Share Posted June 20 Alternator tested bad. So I replaced it. The car still is not charging. When I trace the L and F leads back, where do they go? Do I really need the S to go to the battery? The factory plug only has provision for L and F I am writing this stuff in between Facebook and here... I am juggling both sets of information and responses. No disrespect. 1 Link to comment Share on other sites More sharing options...
Anthony Posted June 24 Share Posted June 24 The service manual section on Charging system has a diagram with 3 wires, but the diagram in the Electrical section only has 2. I looked at my car and it only has 2. Generator is turned on when it receives 12V from BCM on L and sends back a signal on F that determines if the "Service Electrical System" message is displayed. So they are both connected to the BCM. Did you see if the fuse is blown? Link to comment Share on other sites More sharing options...
Stumperific Posted June 24 Topic Author Share Posted June 24 Fuse was good! I went back and tested the two wires into the alternator. Only one was supplying voltage. I had that one pointed at the F terminal when it should be pointing to the L terminal. My original wiring told me to wire it the opposite... so I reversed it and tried that. I now get 14.4 volts across the battery while the car is running. 13 volts when the car is off. I think it is good to go now 1 Link to comment Share on other sites More sharing options...
Anthony Posted June 25 Share Posted June 25 😀👍 Link to comment Share on other sites More sharing options...
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