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Hi all,
I am the proud owner of an '83 MQ LWB ute that I am restoring. Pulling it along is a beastly P40.
However, I believe that the alternator is overcharging the battery. When it's running and I give it a few revs the acid starts to bubble out of the filling points.
I'm just wondering if anyone has heard of, or experienced this happening before?
Any info is much appreciated :)
Cheers, Dec
Yep... 99% chance your battery is gassing waaaay over what it should be so get it sorted ASAP as there will be a lot of hydrogen gas being produced as well.Quote:
Originally Posted by Decthebeast
It can be a dodgy battery as well so either put a voltmeter on the battery terminals with the engine running and check the voltage OR pull the alternator off and get an auto sparky to bench check it for you.
Leave it running too long and you risk a battery explosion as the cells will be getting goddam hot as well
If it's still running the original alternator it will have an external regulator, this could also be the problem.
how do, or can i test the regulator with an average multimetre?
Don't smoke near the thing.
Yeah I thought Reg Rec
Measure you battery voltage.
if its more then 14.2 then its the reg - If yuou have a exter\nal unit - they sit on the left guard.
It nort hard to replace with a internal reg. The internal reg should have 2 wire comming out - L for lamp & B for battery (plus the big nbattery lead.
So, does it have an external regulator mounted on the passenger side inner guard? it will be a rectangular box and have about 6 wires running to it.
You need to make sure the alternator/battery warning light in the dash is working correctly. Does it come on when you turn the ignition on and then go out when the engine is started?
Check the wiring connections at the back of the alternator, are they clean and tight?. Then check the connections at the battery and the main earths from the battery to the body and engine.
Does the battery start the vehicle?.
Start the vehicle and at a fast idle measure the voltage across the battery and across the alternator, are both readings about the same?. Be careful while doing this if the battery is boiling as the risk of it exploding is high. Strongly recommend wearing PPE or at least safety goggles.
Are the readings above 14.2/14.4 volts?
If it is, unplug the regulator, the voltage should now drop down. If it does ,with your voltmeter check for power in the plug at the regulator (vehicle harness side) you should have power in at least 2 of the wires with ignition on. If yes then you regulator is faulty.
If it still has the old mechanical type you can pull the cover of the regulator and inspect the contacts, are they welded together? and signs of corrosion or bugs nest?
You would be better off replacing the alternator with an internally regulated alternator.