1quickTXVette

Hey guys I have a problem that I am so frustrated with and need your help. Here's the full story it is kind of long so bear with me here. On Thursday I went to start the car and only got a click. Not the typical dead battery click click click but just a single click which I think was the sound of the starter solenoid but wouldn't attempt to crank. After clicking start about 10 times it finally attempted to start and fired right up and ran normal. It did this 3 times that day and hasn't done it before or since then. On Saturday I noticed the voltage was lower in the mid 11s and would slowly creep down 0.1 every few minutes. I was on my way to a friend's house to diagnose the problem and stopped to get us some food where it got too low on voltage, the dash lights started going haywire and died in the drive through line. I had to push the car to the parking lot where we got under it and noticed a loose connection to the starter solenoid and the wire covering was getting cracked and chared. I had to call a wrecker to tow it to a friend's house that has a lift where we tried to tighten the connection. As soon as we applied torque to the nut the terminal snapped off. We assumed that the loose connection caused a short and was draining the system and the alternator couldn't keep up. I took the starter off and took it to a local battery shop where they replaced the solenoid. I put the starter back on and went to drive it around to test it out and the problem is still there; the voltage would slowly drop and I barely made it back to the garage before it would've died on me once again. When we put jumper cables to it, the battery began to charge back up and we got it up to 13v. We are thinking it has to be the alternator and that the starter solenoid being loose was just a coincidence. I guess I will have to call another flat bed to come get it and take it to the battery shop being it would die before I get it across town to have them diagnose the problem. What do you guys think, do you think it must be the alternator is not working anymore and isn't keeping the systems charged up? Also, I have an A&A kit and was wondering if I'll be able to get the alternator out without issue or if the supercharger kit will need to be partially taken apart? The tensioner is my worry, in that I am unsure if the shop will be able to get to it without taking the kit apart. Do any of you with the kit know if I will be able to get the alternator out easily. I don't think you can get to the tensioner from the top but do you know if you can from the bottom? Thanks in advance guys. I am so frustrated right now and don't know what to do.

Triumph Jerry

Well first off you will have to find out if it's charging, or if the
battery just won't hold a charge.
Sounds like it's not charging to me.

heli-vette

Most auto parts stores will test that for free . A good mech can find bad lugs and cables , the Alternator can be intermittent with a bad regulator/Brushes . Lights going nuts is common when the battery is low , you need about 12.5 + Volts to keep it ready to start .

1quickTXVette

The alternator is not charging the battery but the battery will hold a charge when jumper cables are put on it. I changed the alternator and still have the issue. So as of now we have checked alternator, the battery, pcm, and alternator fuse

eboggs_jkvl

Checked the cables for loose or corroded connections?

1quickTXVette

I have checked the connections on everything that is visible. Unless inside of a harness that is covered is corroded or damaged I do not see any evidence of a wire issue but again.. This is speculation

eboggs_jkvl

Can you charge the battery from the connection out of the alternator? That would verify that the cable route is good.

1quickTXVette

Yes, we have verified that the connection between the alternator and the battery is good.

heli-vette

Start at the alternator ( engine running ) meter out put to ground frame ,should be 13 - 14.5 volts
. Moving from the Alt. to + side of the battery it should be the same to ground . Jumping cables will show the voltage drop in the cable . Switch the meter to A/C to see if the output is clean DC or a diode is shot .

Check the voltage with lights , fans , AC on its shouldn't drop . The regulator could be bad or plug connected to it .

Like I said any auto part store has a free roll out system tester cart they use in the parking lot . Charge the battery and drive it over .

calemasters

The ECM controls the generator output. Check the sense circuit and fuse in the underhood junction box.

Circuit Description The generator provides voltage to operate the vehicle's electrical system and to charge its battery. A magnetic field is created when current flows through the rotor. This field rotates as the rotor is driven by the engine, creating an AC voltage in the stator windings. The AC voltage is converted to DC by the rectifier bridge and is supplied to the electrical system at the battery terminal.
When the engine is running, the generator turn-on signal is sent to the generator from the engine control module (ECM), turning on the regulator. The generator's voltage regulator controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation. The generator F terminal is connected internally to the voltage regulator and externally to the ECM. When the voltage regulator detects a charging system problem, it grounds this circuit to signal the ECM that a problem exists. The ECM monitors the generator field duty cycle signal circuit. The system voltage sense circuit receives B+ voltage that is Hot At All Times through the HORN/ALT SENSE fuse in the underhood junction block. This voltage is used by the regulator as the reference for system voltage control. On vehicles that use a sense circuit connected to the voltage regulator, this circuit must be operating properly for the charging system to work correctly, when there is a charging system concern all circuits at the generator should be tested.

1quickTXVette

Okay here's some numbers for you heli
Battery with car off - 12.33
Battery car on - 11.1
Alternator with car off - 0
Alternator with the car on - 0
Alternator with car on and the cable going to the battery removed - 4

Me and my buddy think that the numbers are pointing to a bad alternator and that icould've just gotten extremely unlucky in getting a bad refurbished one from autozone. I am taking my old alternator and my battery to the battery shop tomorrow morning to have them tested. If the alternator tests bad then I will remove the new alternator from the car and have that one tested. If they are both bad then I'm guessing it could be a bad refurbished one and a new one would fix my issue. If they are both good then then only other thing I can think of would be a bad wire somewhere causing the issue and would just need to trial and error it.

1quickTXVette

Cale -
Tested every fuse in the engine bay and under the passenger floor board and all of them checked out fine. I even changed the horn/alt sense fuse just to be sure and it didn't fix the issue either. We also checked the wires coming from the pcm to the alternator and got 12v 5v and 0v as expected and points to the pcm giving signal and power to the alternator.

wayback

I have been thru 3 refurbished ones on my 85. Crappy work at best.

I think I need a new one on my 07. Going to have it tested and rebuilt localy if needed. Should cost just over 100 bucks.

Good luck to both of us.

1quickTXVette

I just had the battery load tested again and this time it failed and I received a new battery. When I tested it on Saturday all it said was it required it a charge but this time it registered to replace the battery. The alternator put out 0v whether the car is on or off last night so I feel like the battery isn't the problem. Can a defective battery cause the alternator to put out 0v or would it still be putting out the full 13.2 voltage with a bad battery pointing to the battery not being the issue at hand?

heli-vette

Check the plug / wiring supplying power to the alternator . No power to the rotor ..... no power out .

1quickTXVette

isn't what you are suggesting what I spoke of above regarding the 12v 5v 0v. The wiring coming from the pcm to control the alternator showed the correct voltage as listed above. Wouldn't those voltages mean that the pcm is telling the alternator to charge, successfully?

Where are the grounds located that I should check on that would cause the alternator to not have any voltage?

heli-vette

Yes, the alternator is simple ... bolted to ground ( engine bracket ) .
+ output to the battery the only large cable connected . The three
wire plug feeds the rotor , jump the red alt. lead to the battery it should show higher voltage at the battery for a few seconds when connected for the test at idle .

The alternator should have an internal regulator and should be able to run on its own . If the alt. and battery are good all you have left is pcm or wiring issue you haven't found .

Take that over for testing at the parts shop . It's the quickest system test .

1quickTXVette

I took it in to the dealership today and they put the scan tool on it. It is showing the pcm terminal (not sure if that was the proper term) L is not functioning correctly. F is told that the alternator needs to charge the battery and L is supposed to excite the alternator to actually do it's job which is not happening. So basically the pcm is being told that the alternator needs to turn on but the command to start charging never reaches the alternator. He told me it is either the pcm Itself, a loose connection going into the pcm, or a bad ground somewhere. I am taking it back there Saturday morning to have him work on it and get it fixed! I will let you guys know what I find out at that point! Thank you for all of your help and suggestions guys!

Triumph Jerry

HEATWAVE

Good luck bro hope it simple fix