Baffling Electrical Issue

[Jade Dragon]

there has to be a ground fault somewhere in the primary pipeline coming from the battery and alternator. since the car's electrical system is negative switched, if there is a ground fault it can throw off all of the systems. check points on the car agains the negative terminal. Check the resistance of the body, the engine, the alternator body and the body of the ecu. they should read low-nil resistance. If you find one that is abnormally high, then you dont have proper grounding at that point. To test that, run a new piece of braided copper from negative to that point then try starting the car.

YAY for negative switching, it doesnt make sense until you think of it in a physics mindset. electrons are fun. lol (btw i tend to be a physics nerd at times... )

[Trevor]

[QUOTE=FCsvx_Lantern]there has to be a ground fault somewhere in the primary pipeline coming from the battery and alternator. since the car's electrical system is negative switched, if there is a ground fault it can throw off all of the systems. check points on the car agains the negative terminal. Check the resistance of the body, the engine, the alternator body and the body of the ecu. they should read low-nil resistance. If you find one that is abnormally high, then you dont have proper grounding at that point. To test that, run a new piece of braided copper from negative to that point then try starting the car.

YAY for negative switching, it doesnt make sense until you think of it in a physics mindset. electrons are fun. lol (btw i tend to be a physics nerd at times... )[/QUOT

Please note that the symtoms as originally posted do not indicate a ground fault, but rather an alternator rectifier assembly fault, as pointed out in some detail. The above suggestion could lead towards a lot of frustrating messing about for no gain. lol, I more than tend to be an electrical engineer at all times.

[Trevor]

[QUOTE=Antigenus]Ok here are some more clues I have uncovered today, I had minimal time at work today to do this, but here we go...

The power window on the driver side does not work....I could hear a slight grinding/spinning sound, I think the motor is good but the power window regulator I think? is faulty/siezed up.


You will find that a small pastic component which anchors the operating cable to the window has broken. Until you fix it, do not operate the motor as you will tangle up the cable, although this has probably already happened.

Second, the seatbelt on the drivers side also doesnt work. Could it be tied to the power window somehow? But it doesn't work and the lights inside come on/off with door ajaring.


Possibly the cable has wrapped around wiring inside the door but thie is in no way a certain theory.

The voltage when the car fires up cold, is normal flow and drops by -0.1v each few seconds as the car continues to run, obviously faster depending on the electrical stress you put on the car. I can shut the car on/off as many times as I need, obviously until the voltage drops to a unstartable level. This is SO FRIGGIN' STUPID AND COMPLETELY ANNOYING!! AHHH! Anyways, if I immediately turn the car off after the dash panel lights up, it will stay lit up even when the car first starts. You actually have to let some time pass and the car cool down before the dash lights reset and dont come on until a little more idling or driving are done (maybe 2 mins tops)


It is very difficult to decipher exactly what you are describing, but you could be infering an alternator intermittent fault, which is dependent on heat,

I also order a replacement alternator so I can again, rule out this as an issue and I'll have it on Saturday to drop in shiny and new. (I'm not sure if I'm repeating myself.)


This should fix your major problem, provided that the replacement alternator is 100%.

Thanks for all your help to date guys, if this get resolved it will be a miracle.[/QUOTE

N.B. See inserted notes above, as this appears to be the best way to provide the required information.

[Antigenus]

First off, thank you for all the help so far Trevor, and everyone else giving me a hand on this issue. I really appreciate it.

I know I'm pretty stupid with describing this issue, sorry I'm trying! Anyways, if you put a voltmeter right on the terminals of the battery after a cold start (chances are the battery is already below peak charge) the car fires up, and no lights inside on the dash come on and lets say its at 10.4volts it will creep up and actually charge like a normal alternator...after a very brief charging session the car will kick on all the lights, and charging will now turn to a small draining on the battery terminals (same spot) and now for example decrease depending on electrical demand by about -0.5v per every few minutes until it dies.

My battery has been dead so many times now from troubleshooting I wonder if I should go replace it just to make sure it isnt overloading the alternator? I will charge it to full before I install the new one today. Let me know, what ya think

FYI: I got owned by the local parts store for 2 calipers, 2 rotors, and front brake pads for $500....my butt hurts - Atleast they look nice and work great even with me installing them.

[Budfreak]

you have a PM Antigenus.

[Trevor]

Originally Posted by Antigenus

First off, thank you for all the help so far Trevor, and everyone else giving me a hand on this issue. I really appreciate it.


****** Thanks a lot for the kind comment which is much apprecaied.

I know I'm pretty stupid with describing this issue, sorry I'm trying! Anyways, if you put a voltmeter right on the terminals of the battery after a cold start (chances are the battery is already below peak charge) the car fires up, and no lights inside on the dash come on and lets say its at 10.4volts it will creep up and actually charge like a normal alternator...after a very brief charging session the car will kick on all the lights, and charging will now turn to a small draining on the battery terminals (same spot) and now for example decrease depending on electrical demand by about -0.5v per every few minutes until it dies.

*****You quote a possible 10.4 volts but I would not expect the car to crank reliably unless you have near to 12 volts at the battery.

The voltage creeps up you say. It should be up to 14.5 - 14.7 volts almost immediately. i.e After a brief time charging falls off and there is AC on the line. This is indicated because the dash indicator lights are on, for the reasons I have previously explained.

**Everything taken logically, indicates a fautly alternator and in particular a rectifier fault.

My battery has been dead so many times now from troubleshooting I wonder if I should go replace it just to make sure it isnt overloading the alternator? I will charge it to full before I install the new one today. Let me know, what ya think.


*****Nothing indicates a battery fault, but your suggestion of only 10.4 volts is of concern. The alternator incorporates a system of automatic control which guards against overloading. Do not spend money on a new battery until you have replaced/overhauled the alternator and done another test.

FYI: I got owned by the local parts store for 2 calipers, 2 rotors, and front brake pads for $500....my butt hurts - Atleast they look nice and work great even with me installing them.

As you can do this work you should have no problem changing the alternator. Simply follow your nose and replace all as original. Go to it !

Best of luck, Trevor

[Antigenus]

I just threw the 10.x volts figure out to use for example, I wasn't using the actual voltage readings....anyways I got tied up at work late, and I'm gonna do the new install tomorrow morning, i'll keep yall updated....anyways the replacement alternator said peak amps rate to 120, so I figured that was above the 90+ amp ome rating and should be plenty of overkill.

[Antigenus]

Awesome, for now the new alternator fix the electrical problem and the car hasnt acted up yet. I drove it about 2 hours today. Now my new rotors, brakes and caliphers are squeaking like crazy since i could finally drive on them reliably. Its always something... thanks a MILLION for the help all! Now to tackle the next problem.

[Antigenus]

Ok, last night I fried my alternator (again) on my way to a friends driving at night. I had to turn my headlights off about 1 mile from his house and drive with them off so I could get enough power to the engine to keep it from stalling. The only thing GOOD ABOUT THIS, is I finally figured out the car cigarette lighter is the reason the alternator keeps burning up. I had a power inverter in the plug to charge an electronic and that is the root of this whole issue.

[Trevor]

Originally Posted by Antigenus

Ok, last night I fried my alternator (again) on my way to a friends driving at night. I had to turn my headlights off about 1 mile from his house and drive with them off so I could get enough power to the engine to keep it from stalling. The only thing GOOD ABOUT THIS, is I finally figured out the car cigarette lighter is the reason the alternator keeps burning up. I had a power inverter in the plug to charge an electronic and that is the root of this whole issue.

There should be no reason why even a direct short at the cicarette lighter plug, should damage the alternator. The circuit is protected by a fuse, unless something has been tampered with. Check that the correct rating fuse is fitted.

I note that earlier in the thread you posted the following :-

Quote ---I have tried direct wiring the terminals to the alternator with some heavy duty wire to see if that will help, which i still dont think it will.

The alternator is normally protected with a fuse link and the direct wire you describe above will bypass this protection, N.B. As will stupid alternator "uprade" wiring !

Is this extra wire still in place ??????

[Antigenus]

Yea, I do have wire bypassing any protection the alternator has on it, i have the heavy wiring going from the positive post to the alternator post, and the ground going to a frame ground. I will remove that setup and check the fuse on the cigarette lighter but I have no clue why the cigarette lighter is always the culprit. My SVX has been running completely fine since the last replacement until the power inverter (pulls 10 amps) was used and in one single day ruined the alternator.

[Trevor]

Originally Posted by Antigenus

Yea, I do have wire bypassing any protection the alternator has on it, i have the heavy wiring going from the positive post to the alternator post, and the ground going to a frame ground. I will remove that setup and check the fuse on the cigarette lighter but I have no clue why the cigarette lighter is always the culprit. My SVX has been running completely fine since the last replacement until the power inverter (pulls 10 amps) was used and in one single day ruined the alternator.

You have presumed the inverter is the culprit, but it could be something else. It is VERY difficult to locate the sort of intermittent problem you have. I have struck cases where the the cause has been quite beyond expectation and belief. e.g. in your case, possibl a succession of faulty alternators. Remove the extra heavy wiring as a first off.

Check the original wiring for poor connections etc. With the engine running at charging RPM, measure the voltage drop from the alternator output terminal and the battery. This should be less than one volt. Positive meter lead on the alternator main output terminal, negative lead on battery positive.

There is a second pilot wire which the alternator uses to read the battery voltage. With the ignition off, the voltage at one of the smaller connections at the alternator, should read exactly the same as the battery voltage, i.e. read directly off the battery. Check this as well.

I can not see how an inverter drawing ten amps would cause a problem. There is no reason to suspect back EMF causing spikes on the line, but stranger things have happened.

Best of luck, Trevor.

I think your problem here is you're using poor quality rebuilt alternators. My recommendation would be to find a used alternator, or get a subaru reman alternator from the dealer.

Best,

Mike

[Antigenus]

I reordered another alt (will be in this sat) and removed the direct wiring. I have noticed all my replacement alternators have been 80a alts, but have max power of usually 125+ amps. I'm looking for an oem alt or upgraded amp alt as a long term fix after I get this alternator replaced. 10amp on an inverter could be enough to push the alternator to a breaking point, at RMS its 1/8th of the total amps suggested by the alternator, I always find this device at the scene of the crime, makes me want to think its the sole problem. Could just be plain wrong.

[Trevor]

Originally Posted by Antigenus

I reordered another alt (will be in this sat) and removed the direct wiring. I have noticed all my replacement alternators have been 80a alts, but have max power of usually 125+ amps. I'm looking for an oem alt or upgraded amp alt as a long term fix after I get this alternator replaced. 10amp on an inverter could be enough to push the alternator to a breaking point, at RMS its 1/8th of the total amps suggested by the alternator, I always find this device at the scene of the crime, makes me want to think its the sole problem. Could just be plain wrong.

Please be sure that I am not trying to exhibit my knowledge and simply wish to keep you on track with a diificult fault finding issue. A much higher load than you quote in respect of the inverter should not effect the alternator. The current involved is effectively supplied by the battery and the alternator is automatically regulated to remain within the limits of its capacity. As you have mentioned RMS, I wonder if this must mean that ten amps is the rated AC output, rather than the input load on the DC circuit which will be very much higher. However I remain further in the dark, not knowing if the output is 110 or 220/240 volts AC.

Best of luck, Trevor.