MGC Electrical (charging) help
Discussion
Hello all,
I recently tried to blow myself up by jump starting the MGC with the terminals round the wrong way! I fried a small section of the loom from the alternator back 12" or so. This I cut out and replaced.
I have run the car jump starting the correct way round, and although its putting out 14V at the alternator, isnt charging. 10.5V at the batteries. I have tried a 4L voltage regulator replacement, but this hasnt helped.
My ignition light stays on, so was wondering if it is the batteries. They are 6Volt type and possibly a couple of years old. Could bad batteries make the ignition light stay on?
Could I have damaged the little diodes in the alternator, and although its putting out 14Volts, could this be the next thing to change?
The alternator is a 16AC if anyone has one?
Any help would be much appreciated.
I recently tried to blow myself up by jump starting the MGC with the terminals round the wrong way! I fried a small section of the loom from the alternator back 12" or so. This I cut out and replaced.
I have run the car jump starting the correct way round, and although its putting out 14V at the alternator, isnt charging. 10.5V at the batteries. I have tried a 4L voltage regulator replacement, but this hasnt helped.
My ignition light stays on, so was wondering if it is the batteries. They are 6Volt type and possibly a couple of years old. Could bad batteries make the ignition light stay on?
Could I have damaged the little diodes in the alternator, and although its putting out 14Volts, could this be the next thing to change?
The alternator is a 16AC if anyone has one?
Any help would be much appreciated.
justinbaker said:
Hello all,
I recently tried to blow myself up by jump starting the MGC with the terminals round the wrong way! I fried a small section of the loom from the alternator back 12" or so. This I cut out and replaced.
I have run the car jump starting the correct way round, and although its putting out 14V at the alternator, isnt charging. 10.5V at the batteries. I have tried a 4L voltage regulator replacement, but this hasnt helped.
My ignition light stays on, so was wondering if it is the batteries. They are 6Volt type and possibly a couple of years old. Could bad batteries make the ignition light stay on?
Could I have damaged the little diodes in the alternator, and although its putting out 14Volts, could this be the next thing to change?
The alternator is a 16AC if anyone has one?
Any help would be much appreciated.
Oops.....you probably won't have done the alterntor any good.... I recently tried to blow myself up by jump starting the MGC with the terminals round the wrong way! I fried a small section of the loom from the alternator back 12" or so. This I cut out and replaced.
I have run the car jump starting the correct way round, and although its putting out 14V at the alternator, isnt charging. 10.5V at the batteries. I have tried a 4L voltage regulator replacement, but this hasnt helped.
My ignition light stays on, so was wondering if it is the batteries. They are 6Volt type and possibly a couple of years old. Could bad batteries make the ignition light stay on?
Could I have damaged the little diodes in the alternator, and although its putting out 14Volts, could this be the next thing to change?
The alternator is a 16AC if anyone has one?
Any help would be much appreciated.
First thing would be to check the continuity of the charging wire from the back of the alternator to the connection with the main battery feed wire on the starter. You might get 14v from the back of the alternator because you are checking it (presumably) directly between there and an earth, thus creating a circuit through the multimeter - if the charging wire is fried further along than you think, or elsewhere as well, you would then not get the circuit made when checking across the battery terminals, hence reading 10.5v there. I think that the ignition light on a switched earth so that it goes out when it gets a signal from the alternator - have never heard of bad batteries making the ignition light stay on.
Before you change the alternator, check the continuity/integrity of all the wires in the charging circuit, and then take the alternator to your local electircal factors and get them to test it.
MG Mark
Hi Justin, I saw those thick jump leads in your boot and wondered if you'd got two 6v batteries that were failing
I'd suggest, take alternator off and take it to a refurber and ask him to check it out
See http://www.pistonheads.com/gassing/topic.asp?h=0&a... for various advice from others
For the future to make starting easier you'd do better to swap to one 12v to fit in where one 6v used to sit, it gets rid of the additional battery terminals and leads that can get dirty and/or the extra resistance to starting
Also replace (on top of any you've fried) all the main leads to battery, starter, solinoid and earth leads and earth strap engine to body after cleaning all terminal connections
If you need a second pair of hands give me a shout, Nigel
EFA - to take out the bit I might have got wrong
I'd suggest, take alternator off and take it to a refurber and ask him to check it out
See http://www.pistonheads.com/gassing/topic.asp?h=0&a... for various advice from others
For the future to make starting easier you'd do better to swap to one 12v to fit in where one 6v used to sit, it gets rid of the additional battery terminals and leads that can get dirty and/or the extra resistance to starting
Also replace (on top of any you've fried) all the main leads to battery, starter, solinoid and earth leads and earth strap engine to body after cleaning all terminal connections
If you need a second pair of hands give me a shout, Nigel
EFA - to take out the bit I might have got wrong
Edited by SB - Nigel on Monday 10th March 19:08
Nigel - Sorry I missed you. I am still to work out what sports car you arrived in!
I havent looked today as its been ruddy horrid outside. Finished contracting on Friday, so I have till Thursday free to play around with the MG.
I will take the alternator to a test station, as soon as it clears up enough to get it off.
Pop in if you are about!
I havent looked today as its been ruddy horrid outside. Finished contracting on Friday, so I have till Thursday free to play around with the MG.
I will take the alternator to a test station, as soon as it clears up enough to get it off.
Pop in if you are about!
justinbaker said:
Nigel - Sorry I missed you. I am still to work out what sports car you arrived in!
checky devil, see my profolie justinbaker said:
I havent looked today as its been ruddy horrid outside.
what ! you've got a bonnet and a tailgate on a CGT to offer protection 
get on with it 
justinbaker said:
Pop in if you are about!
we were just passing the other day from taking Mrs Beer to Garth's - if you want a hand but can't find anyone better just let me know Gassing Station | MG | Top of Page | What's New | My Stuff