Hi

I have a 1995 Mitsubishi RVR Sports Gear automatic 4x4 petrol turbo. The battery appears to be overcharging (its starting to weep). Most likely problem is faulty alternator or voltage regulator. Can anybody tell me if the voltage regulator is positioned internally or externally of the alternator.

Thanks

It is inside of alternator. But I have never seen them fail in this manner. Most likely it is a bad battery.

This should be easy enough to check, just hook-up a voltmeter! And remember that alternator output can be be 13.5-14V.

Hi

Thanks for your reply. This has being an ongoing problem. Its already destroyed 2 good batteries. I reckon the problem must be connected with the charging system.

The charging rate varies, its not always 13.5-14 , it can be higher and yes the charging system can overcharge. A faulty voltage regulator can in fact constantly cause the system to overcharge. Upon starting the alternator puts out 15-16 v to accomidate the power needed of the battery to start the engine, and thus breaks down to about 15-14.5 til after a bit of running when the battery has peaked back at its max state. The alternator also varies its output depending the electrical load on it , as in electronics running , ac , cooling fans on and headlamps etc. On the alternator is a status charge wire that leaves the alternator and impend charge wire and icl wire in teh connector , sum times 2 ics wires on the alternators connector. If one these wires are grounded or shorted , it will make the regulator constantly overcharge. Check the wiring as they pass in a high heat area and teh location of the alternator makes it easily frayed sumtimes, so check the wires, make sure they are burnt , sticking together /shorting each other out near the plug in or harness loom. Also make sure they are not contacting on the positive lead at the alternator.

if all is well , the voltage regulator is going to be the culprit of teh overcharge. At times the casing will shear , break or nodes will wear down with age causing the impendant side to ground on the inside of the alternator case causing an overcharge , this is similar the case why they stop charging also.

Thanks.





quote name='KiT TeUnG 2549' date='Mar 30 2009, 05:53 PM' post='249449']
The charging rate varies, its not always 13.5-14 , it can be higher and yes the charging system can overcharge. A faulty voltage regulator can in fact constantly cause the system to overcharge. Upon starting the alternator puts out 15-16 v to accomidate the power needed of the battery to start the engine, and thus breaks down to about 15-14.5 til after a bit of running when the battery has peaked back at its max state. The alternator also varies its output depending the electrical load on it , as in electronics running , ac , cooling fans on and headlamps etc. On the alternator is a status charge wire that leaves the alternator and impend charge wire and icl wire in teh connector , sum times 2 ics wires on the alternators connector. If one these wires are grounded or shorted , it will make the regulator constantly overcharge. Check the wiring as they pass in a high heat area and teh location of the alternator makes it easily frayed sumtimes, so check the wires, make sure they are burnt , sticking together /shorting each other out near the plug in or harness loom. Also make sure they are not contacting on the positive lead at the alternator.

if all is well , the voltage regulator is going to be the culprit of teh overcharge. At times the casing will shear , break or nodes will wear down with age causing the impendant side to ground on the inside of the alternator case causing an overcharge , this is similar the case why they stop charging also.
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How long did it take for these batteries to fail? Were they both from the same source?

In ether case, you should hook-up a voltmeter and monitor the voltage for a while. It is easy enough to do!

Hi

Both batteries failed over a 2-3 month period. They were sourced from different suppliers.