electrical gremlin, Help, I am totally stumped!

[beetos]

Last week I left my trunk lid open and it completely drained the battery. I trickle charged it and it is nice and strong angain. I put the battery in the car awaiting some other parts as I am overhauling the cooling system.

When I connected the battery it was sparking and the terminal getting hot like it was drawing current. I discoved that if I undo the main cable at the back of the alternator it no longer draws current and you can connect the battery terminals without the terminal posts arcing like mad.

However, now the car is acting very strange. Both turn indicators on the dash are constantly dim and with the ign swich off, the damn wipers run on fast and the car does not show any ign lights or want to crank when the ign is turned.

I am suspecting the immobilizer has somehow gone south. But why would my alternator now want to short out? can completely draining the battery have this effect? Battery is now good as I checked it for volts / charge. Now I am thinking that maybe the last time it ran the alternator packed out and it was it that killed the battery, but I never saw any dash lights to indicate this.

Does anyone know where the fuseable links are?

Any help would be most appreciated, I am at my wits end with this.

[632 Regal]

voltage regulater sticking? Diodes in the alternator gone bad?

[beetos]

I was thinking diodes myself. Did not know the regulator could stick? Would any one of these conditions be caused by completely discharging the system?
Cheers

[632 Regal]

possibly but can cause a discharge of the system...if that makes any sence.


I was thinking diodes myself. Did not know the regulator could stick? Would any one of these conditions be caused by completely discharging the system?
Cheers

[Javier]

are you absolutely sure you did not reverse battery polarity when re-installing?

Fuse links will not protect you from the short caused by the alternator (shorted diodes or reversed polarity). Also batteries may suffer irreversible damage when deep discharged. Is it charging and holding charge? Does it reaches 14.5 volts in the charger? Low battery in this cars is a mess.

Javier

[joshua43214]

If the right diodes fail in the alternator, it will drain the battery. The diodes can blow from reversing the polarity on the battery, overloading the alternator, jump starting, or age.

The diodes convert the AC electricity to DC current, so if they are blown, you will feed AC current thrugh the system which can also cause numerouse bugs.

I have seen many alternators short out internaly from coolant getting in them during a colling system flush. Sometime allowing it to dry out will "cure" it, but as often as not, there is damage done to it and it will need to be replaced. Sounds to me like it was a shorted alernator that drained the battery rather than the trunk light. If the cables are actualy getting hot, that means you have a dead short, and this will destroy a battery in very short order.

[beetos]

Thanks for the response guys. Double checked the polarity of the battery and there is no problem there. The coolant in alternator sounds like it may have happened as I busted open the thermostat housing and is pissed out of there probably all over the alternator.

One thing that is scaring me though is the rest of the electrics are acting up. Wipers running continuously when the ign is turned to accessory, no dash lights, etc. If it was just the alternator, then disconnecting it should let all the other stuff work as it was. I cant work this out.

I have a full set of diagrams now and can see the layout for the power distribution etc and will start to check it. I can't understand why its acting so different as nothing was physically changed between the discharge event and now.

The battery seems to be holding charge and certainly runs the wipers fast enough. Voltage readings come back ok. Any more ideas would be appreciated.

[beetos]

So I am making progress. Apparently, the battery that was showing good voltage when connected up to the car was f'd up. A new battery and things are looking good again. Alternator is in the shop. Not a cheap rebuild if it has gone south. The diode packs are expensive!

Anyway, I guess I got a free crash course in E34 electrics as well as a few more gray hairs.

Next project is to install the new Racelogic traction control system (money has been going fast this month!)