Mk1b Alternator wanted

[AndyB]

Hi all,

I'm looking for a replacement 70 amp alternator. Mine doesn't seem to be up to the job anymore. I have the symptomatic "engine compartment cooling fan" and "Discharge" warning lights showing when the car is running.

I can't spend too much as I've still not even got the car moving yet!!

Thanks,

Andy

[julianw]

Hi Andy

Fancy cutting your teeth on repairing an alternator? To expand, I had my alternator give up charging and very quickly got to the point where the battery was flat. The AA bloke I called out, took a hammer and piece of wood to the alternator body while the engine was running - "not too hard, mind! Too hard and you crack the alternator frame". Bingo, the charge light goes out and the battery starts getting juice. His explanation? The carbon brushes that contact the commutator (shiny copper strips you may be able to see through the gaps) wear down but get stuck in their channels, despite the springs behind them that are supposed to keep them pushed against the copper. The judicious tap he administered was enough to jolt them free and the springs pushed them back in contact with the commutator again. I opted to replace the alternator after this episode (I was reliant on the car as a daily drive), but I was tempted to follow his advice and just dig the old brushes out and replace them. I even took measurements of the carbon brushes that I would need to find/cut some bigger ones down to, to act as replacements. Shame I lost them when my last phone went bang. Can anyone provide the dimensions?

Good luck
Julian

[jimi]

There are other faults that can cause the "3 lights of death" ;)
Slightly more technical solutions than "hit it with a piece of wood" :rolleyes: http://www.mr2oc.co.uk/know-your-2-knowledge-base/mr2-mk1.html?catid=3&kbartid=51 and http://www.mr2oc.co.uk/know-your-2-knowledge-base/mr2-mk1.html?catid=3&kbartid=3

[superwhite90]

I bought one for £125 and comes with a warranty of 1 year if you are interested i'll find you the details.

[AndyB]

There are other faults that can cause the "3 lights of death" ;)
Slightly more technical solutions than "hit it with a piece of wood" :rolleyes: http://www.mr2oc.co.uk/know-your-2-knowledge-base/mr2-mk1.html?catid=3&kbartid=51 and http://www.mr2oc.co.uk/know-your-2-knowledge-base/mr2-mk1.html?catid=3&kbartid=3

Hi Jimi,

Quick run through your diagnostics shows that I am getting battery voltage at the main connection but only on one of the 3 plug pin connections. Reading your how to article on mr2oc that infers that I have a fault int. wiring. I'm not sure how that makes me feel. I'm not the best at vehicle electrics but will take a look.

[AndyB]

False alarm. Actually, I'm the king of false alarms what with my oil filter yesterday.

Turns out I'd not read your article word for word and was testing with the ignition off. Both of the white leads in the plug are only live on ignition. One does read slightly lower 11.8v with the other side white lead reading 12.8v. So I'm back to thinking that it's th alternator at fault. Now where is that block of wood and my mallet..


I'll save my big potential false alarm concern for later today..

[AndyB]

@julianw. I also tried your "bash it with a big stick" trick but to no avail. Would have been funny (but quite handy) if this had worked.

[julianw]

If you're imagining a scene like Fawlty Towers with the Austin 1100 ("Right, I warned you about this!") alas, it wasn't a case of flaying the bonnet with a willow branch with the leaves still on!

Sent from my GT-S5830i using Tapatalk 2

[Gilles27]

I will keep a hammer and lump of wood in my boot from now on!

[AndyB]

Something to add to this thread. I'd seen mk1 alternators advertised at TCB for a decent price, and on calling spoke to a very nice, knowledgeable bloke. The alternators they have are all 1 type - the 60 Amp units, that I have read were the type fitted to the mk1a, with a 70 Amp unit fitted to the mk1b. The TCB guy said that the test sheet showed that it was labelled as 60 As but maxed out at about 70 amps at 6000 rpm. He said that they supply these to anybody with a mk1 and to was the first time he'd been questioned about 60 versus 70 amps. Should I be worried about fitting the 60A variant? It's a good price at about £112 + £12 postage.

I'm also considering a local alternator rebuilder, who thinks it may be about £60/£65 to repair mine - has anybody gone down that route before?

[tommundy]

I need one too as the cold night on Sunday killed mine.

Thankfully, I knew what the combination of warning lights on the dash meant, so turned back home when it had gone to avoid being stranded.

It'd be good to see people's thoughts. The part no. given on TCB's website is QA1440, which appears to be a generic one.

[superwhite90]

Has anyone got a spare bush that goes in the bolt hole?

[jimi]

According to the EPC the only MK1's fitted with a 60A alternator were EUG spec (Europe General) 1984/11 - 1985/06 part # 27060-16050.
All the rest including Gen spec (General countries) 1984/11 - 1989/12 had a 70A alternator part # 27060-16082

http://www.mr2mk1club.com/images/imported/2014/11/alternators-1.jpg

[Vistalite]

I replaced mine recently and used a Sovereign SA990 with no issues at all.

Looking at their tech spec it lists this for use on years '85 - '90 and is rated at 60A.

[jimi]

A 60A will work fine, although it may struggle a bit to keep the battery fully charged in very high demand periods i.e. at night, in the winter, when you are have everything running - lights, heater blower, heated rear screen, stereo, especially if your battery is getting on a bit.
If you don't drive in those circumstances then it's unlikely to cause any problems.

[tommundy]

I've just ordered an alternator from TCB. Due to my car being a 1990, he's including an alternator bracket as well in-case mine is the different fitting type; top service!

I'll be fitting it on Saturday providing it arrives tomorrow.

I'll report back.

Cheers,
Tom