Big Cat Posted June 2, 2013 Share Posted June 2, 2013 Ok, So I am having problems with my 3T Alternator in my TT141 Corona. It is believed to have a leaking diode in the alternator which is draining the battery of all of its life if left connected overnight. I have tested it with a voltmeter and what not and when there is power connected from the alternator to the battery there is a 2 amp discharge going through. The Alternator still charges the battery and what not when the car is running, it's just when the car is off, there is a discharge somewhere. When I am not using the car I disconnect power from the alternator to the battery so there isn't any discharge, and then reconnect it when I take the car out, this seems to be working fine so far. I am not entirely sure if I should go through the hassle of a new alternator or get it reconditioned and what not. Would love to hear suggestions / help! Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 2, 2013 Share Posted June 2, 2013 Far more likely the external regulator is buggered. Unplug it rather than the battery and see if the battery is flat in the morning. Should be on the left hand side just behind the battery, round plug on the TT-140's if my memory serves me. Quote Link to comment Share on other sites More sharing options...
Big Cat Posted June 2, 2013 Author Share Posted June 2, 2013 The Green round plug behind the battery is what i unplug when i don't use the car, not the battery. Bad explanation on my part haha. But yes when I unplug it using the round plug and leave it overnight, the battery is fine in the morning when i replug it and start it back up. Thoughts? Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 2, 2013 Share Posted June 2, 2013 That black box that's attached to that plug is the regulator, that is far more likely to be your problem. If the Alternator was faulty the idiot light would be on or the system would be over charging. Quote Link to comment Share on other sites More sharing options...
Big Cat Posted June 2, 2013 Author Share Posted June 2, 2013 I see what you mean, will have a look into that. Cheers for the info frosty! Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 2, 2013 Share Posted June 2, 2013 KT-140 and YX-70 use the same regulator, some are solid state and far more reliable. The later RWD Starlets may use them to but I'm not as familiar with then. I have used the early rectangle plug ones to by swapping over the plug, just hook up the new plug but matching where they go in the regulator, The colors don't match but you will be able to see where each wire goes by taking of the cover on the regulators underside. If the reg is the older contact type you may be able to clean up the contacts in it under the top (black) cover and get it working again or you could take it to an auto sparky so he can set it back to working settings. The solenoids and contacts can go out of calibration or get burnt over time. The older cars with a generator actually had an adjustable reg on them that you set your self with screws to set the on and of points dependent on the voltage of the battery while the engine was running. Quote Link to comment Share on other sites More sharing options...
FuzzayD Posted June 4, 2013 Share Posted June 4, 2013 you could put an ammeter in series across your battery's positive cable when the key is off and see how much current is being drawn it should be none or below 0.03amps with all your vehicles lights including interior lights off if not, then unplug your altenator see if it drops to 0. if not plug it back in then take out a fuse, if its still drawing current put the fuse back in and try the next one ect... I've sometimes seen where a glove box light doesn't go out when shut causing the battery to drain. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 14, 2013 Share Posted June 14, 2013 you could put an ammeter in series across your battery's positive cable when the key is off and see how much current is being drawn it should be none or below 0.03amps with all your vehicles lights including interior lights off if not, then unplug your altenator see if it drops to 0. if not plug it back in then take out a fuse, if its still drawing current put the fuse back in and try the next one ect... I've sometimes seen where a glove box light doesn't go out when shut causing the battery to drain. You forget one thing. Even with the Regulator unplugged the Alternator is still hocked directly to the battery by the main charging wire and so is everything else in the car. If unplugging the Regulator stops the battery going flat that's the problem. You can do the same thing with a IR (Internal Regulated) one to buy unplugging the plug that has the lighter cables. All you are doing is removing the mechanism that controls the charging the diodes are still in play to. Everything works as normal except no charging is happening and the idiot light doesn't work. Quote Link to comment Share on other sites More sharing options...
hillman1 Posted June 15, 2013 Share Posted June 15, 2013 jut put a kill switch on the main power lead from battery and flick it off overnight Quote Link to comment Share on other sites More sharing options...
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