Re: Zel's Fleet Blog...Jag, Citroens, Mercedes, Sinclair & AC Model 70
Posted: Tue Nov 16, 2021 11:41 pm
Right...time to quit putting it off, the alternator needs sorting on the Jag.
By the standards of this car it's not actually too bad to get to.
Of course being a Jaguar there's a pipe (can't remember if it's power steering or an oil cooler line) which is positioned precisely so as while it's not an actual problem, is really *annoying* when you're trying to get to the back of the alternator.
Said oil lines will also make getting the alternator out a royal pain if it needs to come out as I don't think it will fit between the oil lines and the engine mount...so let's hope it doesn't need to come out.
Based on the symptoms I've had my hunch is that we've got sticky/worn out brushes and/or a failing regulator. The alternator on this car has always been a bit on the weak side (even keeping in mind the Lucas A115 is only rated at 55A, which isn't a lot for a car like this) even before it started randomly stopping charging.
Before I even got the tools into the engine bay the first step was of course to disconnect the battery. It's smart for pretty much anything in the engine bay really, but faffing around on the charging system with it connected would seriously be flirting with disaster.
Not all that many connections to the alternator, but took several photos of what goes where for future reference.
At this point I had to go rummaging in the toolbox...those tiny little hex head screws I think are a BA size...these saved my day.
Apparently these were originally used for servicing magnetos many years ago - which gives an idea how old they are.
Back cover off meant I could get a better look, albeit via the camera as my view was of course obstructed by the aforementioned oil lines.
I ended up removing the brushes complete with the regulator (rectangular silver box above centre frame). Had to cut one wire as I couldn't for love nor money get this bolt to come out. That black wire is attached to a ring terminal. If I can't get it out I'll just solder and heat shrink the new reg lead on to it, not the end of the world. Now I actually know for certain there is a bolt holding the ring terminal down that's half the battle, I was trying to work this out by Braille at the time.
There we go. One set of brushes and regulator.
Compared to photos of new brush sets for the Lucas A115 alternator the brushes don't look *massively* worn, but there's a good 5mm difference between the two which can't be good I reckon.
Equally suspiciously there are signs in the potting compound that at least some of the magic smoke has escaped. It may just be due to moisture ingress and old age...but generally the potting compound failing on things like this isn't ever a good sign.
A new regulator isn't expensive and it would be silly not to replace it given the situation. Especially as the alternator has been obviously weak as long as I've had the car.
Guess we'll see when it goes back together again! *If* I can figure out how to reassemble it!
Hopefully this will get the charging system going again, then she should hopefully be more or less ready to move on to her new owner.
By the standards of this car it's not actually too bad to get to.
Of course being a Jaguar there's a pipe (can't remember if it's power steering or an oil cooler line) which is positioned precisely so as while it's not an actual problem, is really *annoying* when you're trying to get to the back of the alternator.
Said oil lines will also make getting the alternator out a royal pain if it needs to come out as I don't think it will fit between the oil lines and the engine mount...so let's hope it doesn't need to come out.
Based on the symptoms I've had my hunch is that we've got sticky/worn out brushes and/or a failing regulator. The alternator on this car has always been a bit on the weak side (even keeping in mind the Lucas A115 is only rated at 55A, which isn't a lot for a car like this) even before it started randomly stopping charging.
Before I even got the tools into the engine bay the first step was of course to disconnect the battery. It's smart for pretty much anything in the engine bay really, but faffing around on the charging system with it connected would seriously be flirting with disaster.
Not all that many connections to the alternator, but took several photos of what goes where for future reference.
At this point I had to go rummaging in the toolbox...those tiny little hex head screws I think are a BA size...these saved my day.
Apparently these were originally used for servicing magnetos many years ago - which gives an idea how old they are.
Back cover off meant I could get a better look, albeit via the camera as my view was of course obstructed by the aforementioned oil lines.
I ended up removing the brushes complete with the regulator (rectangular silver box above centre frame). Had to cut one wire as I couldn't for love nor money get this bolt to come out. That black wire is attached to a ring terminal. If I can't get it out I'll just solder and heat shrink the new reg lead on to it, not the end of the world. Now I actually know for certain there is a bolt holding the ring terminal down that's half the battle, I was trying to work this out by Braille at the time.
There we go. One set of brushes and regulator.
Compared to photos of new brush sets for the Lucas A115 alternator the brushes don't look *massively* worn, but there's a good 5mm difference between the two which can't be good I reckon.
Equally suspiciously there are signs in the potting compound that at least some of the magic smoke has escaped. It may just be due to moisture ingress and old age...but generally the potting compound failing on things like this isn't ever a good sign.
A new regulator isn't expensive and it would be silly not to replace it given the situation. Especially as the alternator has been obviously weak as long as I've had the car.
Guess we'll see when it goes back together again! *If* I can figure out how to reassemble it!
Hopefully this will get the charging system going again, then she should hopefully be more or less ready to move on to her new owner.