Mk1 1.8 Alternator woes

Hi Ian,

I fitted a voltmeter to the car some years ago for added peace of mind, monitors state of charge even if the light goes on the blink.

Dave 

So ten days ago I was reasonably confident that the alternator problem had if not gone away at least receded into the distance. On Tuesday of this week I drove to my usual day of volunteering, a journey of about 26 miles and on the way home the dreaded light came on and stayed on. I nursed the car home as I was unsure how far it would run just on the battery and got it safely back on the drive.

During the day my replacement brushes had arrived having decided to order them just in case, so as Wednesday was going to be a fine mild day I decided to bite the bullet so to speak.

The day did indeed dawn fine and mild so I set about removing the alternator, how difficult could it be? Disconnected the battery, removed the air pipe and I could then see the offending item. Slackened off the adjuster unit, so far so good but then access to the bottom bolt was awkward so removed the charcoal canister to make life easier. Unbolted the main cable but the plug was a little more difficult, then set about removing the bottom pivot bolt.

You probably know what is coming next, so then I had to remove the aluminium support bracket for the inlet manifold before I could withdraw the bolt. At last the alternator was free and just needed lifting out, except that there is insufficient space unless one drops the under tray.

Not wanting to get the jack and axle stands out as the day was wearing on, I removed the throttle body to make space to discover that the small pipe underneath contains coolant and needed plugging. Eventually the alternator came free and as it was starting to go dark and cold I retreated into my workshop.

The alternator bolts released easily and with a few judicial taps the casing parted and finally I could see the brushes. 

Removing the three screws was yet another experience until finally all was revealed.

Think the old brush on the left was wearing down a little,

The casing halved were wire brushed, new brushes installed and using a thin piece of wire to retain them all was assembled and screwed together. Time to call it a day until I realised that the case halves were incorrectly aligned so screws out, twist case and screws back in.

So now just need to put it all back together and of course the weather changed for the worse, until today. Ever thing reassembled eventually, turned key and low and behold it started and more importantly the light stayed out and the belt squeal has disappeared.

So a result I think, new alternator £163 + postage new brushes £2.99 including P&P and two days of my time which would have been similar for either option.

Unfortunately getting up and close to these oily bits reveals numerous other jobs that need looking at, but that is for another hopefully warmer day.

Hopefully this is the last post on this subject, so thanks again for everybody’s help and advice.

Dave

 

 

Well done Dave - proved the point anyway and trust me it will be much easier second time around, particularly if you greased up that pivot bolt  The Mk1 1.8 and MK2 thread into the alternator casing at the front which is a poor design. The MK1/Eunos 1.6 has a longer bolt that threads into a nut at the back which makes far more sense. 

Having just rebuilt that MK1 1.6 alternator I messaged you about with a new regulator complete with brushes I do agree it is a labour of love.

To test on my car I only had to remove the crossover pipe and disconnect the battery before 12mm adjuster and 14mm pivot.

Very pleased to say it worked perfectly at 14.62 volts from cold so the time and effort worth it. when I removed the regulator and brushes it was very clear that both brushes were well worn down. Surprised that yours appear to have unequal wear, or perhaps the other was similarly worn down? Looking at the amount of brush left I have no doubt this was an issue. Uneven  brush wear is what I would expect from the MK2 Hitachis, not the MK1/Eunos Mitsubishi          

What’s with this second time around! 

The bolt was not a problem to unscrew, in fact once loose it wound out with just fingers and yes it now has copper slip as well.

It does appear to be a bit of a bad design making it slide out towards the brace one assumes that there is sufficient space at the front if the 1.6 is that way around.

Dismantling the alternator was again straight forward apart from the three cross head screws which despite penetrating fluid were wanting to chew out. A screw driver on the edge and a hammer cracked them loose.

The LH brush is old and the RH new, and whilst both old brushes were a similar length the spring pressure on the front brush felt considerably less, perhaps explaining the intermittent contact.

Glad your rebuild was a success, did your alternator lift out or drop down? If lift I wonder what I was doing wrong?

Any way sorted now and if it lasts another 25 years, it will not be my problem next time around.

Dave

For me it is more like 20th time around and yes much easier on the 1.6 where pivot bolt can be easily removed from the front. This used to be a talked about mod particularly for the MK2 where corrosion causes more of an issue. Drill out alternator thread at front and fit MK1 1.6 longer bolt and nut at back.

On the 1.6 cars, the alternators can be threaded out through the top in front of the radiator on the left hand side.

Given the quality of the Mitsubishi units - A2T80391 OE on MK1 1.8?, your 25 year estimate may well be accurate. My parameters are a little different as occasionally expected to refurbish/test these for sale. It’s quite a process but I feel better about charging reasonable money for clean, tested and guaranteed units that I would/have fitted to my car.

Those three screws that hold the regulator/rectifier to the bottom half of the case could be a show stopper. As explained in my instructions an impact driver really required to ensure you are not thwarted at this crucial stage.

The short length of the brush you replaced is enough to convince me that replacement was the correct way to go, so the effort and thread thoroughly worthwhile. When they get short, contact becomes intermittent as the spring strength versus carbon dust resistence eventually stops sufficient contact.            

Excellent result Dave and many thanks for the update and write up. Out of interest how many miles has your car covered? I realise that mileage covered won’t rearly equate to alternator brush wear but would still be interested to know. Also what model number is your alternator? If it’s the same as mine for £3 I might order some brushes for mine.

Thanks
Well done.
D

Hi Combemartin,
Sorry only just found this post, not sure why but it has only just appeared.
The car is 25 years old and has done some 130000+ miles, whether it is the original alternator I would doubt, but was certainly on the car when I got it some six years ago.
Alternator details, easy to see off the car, not so on.

image

Brushes from eBay

Hope this is useful and again apologies for tardiness.

Dave

Hi Dave, thanks for that. My car has done about 80k miles and I’m pretty sure it’s the original alternator. I ordered a set of brushes a few weeks ago as there was only one set available and for £3 I thought what the heck. Using my normal twisted logic, if I didn’t buy them I would need them, and if I bought them I will never need them.
Thanks again.
D.

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