electrical and ignition Boiling Battery Super Hi Volts

[Guest]

I have a 72' 2002tii.  I moved the battery to the trunk and have been having problems since.  I now burn the headlight bulbs out.  When the car is running I get strainge voltage readings off the battery 9.9 to 17.5.   I ruined a battery and have almost burnt the car up because the wiring on the headlight switch inside the dash melted and had to re do all the wires that go to the headlamp switch.

 

Before I tear the alternator out I want to ask if there is something else I can do or try to figure out this high voltage issue.  Thank You.

 

cory.

[Tommy]

This sounds more like an issue with voltage regulator. If charging voltage is ok or even too high the alternator seems to be working. If you have original system the regulator is located at driver side fender. It may be also in the alternator if the alternator has been replaced with later model.

Tommy

[Guest]

I have replaced the voltage regulator.  The alternator is very old and dirty looking.  Looks like a bitch to replace since its a tii hanging under the car.

[TobyB]

I suspect your alternator is not reading the true battery voltage, and trying to compensate.

Or it's simply unable to sense battery voltage at all...

 

Broken record, I know, but check all your connections and all your grounds.

 

And use a voltmeter to check for voltage drops along the way.

[peterschop]

Did you replace the voltage regulator before or after this happened? You could have put in a bad regulator. You should never have more than 14.5 volts. Get this fixed before driving anymore. 

[Tommy]

Well in that case I guess the alt is the only chance. I don't think there is a chance to mess the regulating circuit wiring while relocating battery. Or do you think that might be possible?

Tommy

Well in that case I guess the alt is the only chance. I don't think there is a chance to mess the regulating circuit wiring while relocating battery. Or do you think that might be possible?

Tommy

Well in that case I guess the alt is the only chance. I don't think there is a chance to mess the regulating circuit wiring while relocating battery. Or do you think that might be possible?

Tommy

[Tommy]

I hate this pad thing !!

[adawil2002]

Is everything properly grounded since moving the battery? Could have missed something simple like that, double check that there's a strap from body to the engine block.

[Guest]

I replaced the voltage regulator before I moved the battery, its a Behr 14.4,  but I can't recall really when all this started happening, but am pretty sure it started after I moved the battery to the back but I could be wrong.  I put the one red wire from the positive battery to the + starter, and then ran a long  heavy gauge wire from the positive of the starter to the positive battery.  then a ground from the battery to a spot in the trunk where I bolted it down making sure there was metal to metal contact.  I left the - battery wire that goes from the engine to the inner front  firewalll where the stock battery location is..  Maybe something isn't getting grounded properly or the alternator is shit?  Does running such a long positive ground wire do anything?  It is the Top End performance kit, its actually welding copper wire they give you as well.

[Guest]

Another thing I noticed on the alternator is the brown wire yes is going to the ground on the block but then there is another brown wire from the main wiring alternaor wire loom that is unhooked and not seeing anywhere to connect it.

[John_in_VA]

I added a ground in the trunk when I moved my battery.  Not saying that's your problem but it was suggested by the group here.

[adawil2002]

Another thing I noticed on the alternator is the brown wire yes is going to the ground on the block but then there is another brown wire from the main wiring alternaor wire loom that is unhooked and not seeing anywhere to connect it.

 

Do you have a wiring diagram for your Tii, there's one in the red Haynes book. If you don't have a copy you should buy one.

http://www.amazon.com/1602-2002-1959-77-Haynes-Manuals/dp/0856962406/ref=sr_1_2?s=books&ie=UTF8&qid=1412979507&sr=1-2&keywords=bmw+haynes+manual

[TobyB]

 

there is another brown wire from the main wiring alternaor wire loom that is unhooked

Oooh, ground is brown, the car around. 

 

Wonder if that's the ground to the voltage regulator?

 

Meters are so useful, especially the Multimeter- type...

 

t

[John_in_VA]

Electrical diagrams: http://www.2002tii.org/kb/246

[DRedman]

As Toby said the brown wire that's not connected should be going to the regulator.  The alternator plug should have three terminals that have 2 blue wires on one and a black and a brown on the other 2.  If that ground wire is just hanging there it should go to the regulator.  It may have broken when you replaced the regulator.  The other brown wire is the alternator frame ground  that's attached to the block.  I wonder if the loose brown wire was causing the alternator to put out high A/C voltage that's frying your wires, boiling your battery, etc.