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MG ZT, Rover 25
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Discussion Starter · #1 · (Edited)
Symptom - clock, instrument and lights flickering. Varying voltage across battery terminals when engine running.

Decided to replace regulator/ brush assy - re. earlier thread: Lights flicker when engine runs
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I thought this would be an easy job, but the designers must have been having a laugh when they put in the alternator. I used practically every spanner in the tool box as there are loads of different size nuts and bolts, access is poor, and its a struggle to get the alternator out of the engine bay when its unattached!

This is what I did...

1. Disconnect -ve lead on battery.

2. Remove alt belt by using a 13mm spanner to loosen the tensioner pulley and then ease it off.
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3. Disconnect connector and +ve terminal from back of alt.

4. Undo nut and pivot bolt on top of alt. It's a good idea to remove top bracket if poss. but in my case it was corroded onto place and the bolt was beginning to round so I couldn't without lots of extra work.

5. Undo nut and pivot bolt under alt. You can't see it and it's tricky to access, but I got it off when I released the bolt had a random 17mm sized head on it!

6. Remove the pivot bolts and work the alt off its brackets.

7. Remove alt from engine bay. This was tricky in my model as the alt top bracket couldn't be easily removed. But got it out by bending pipes out of the way and swivelling up engine damper arm.
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8. Undo 2 x nuts and screw on back of alt to take off plasic cover plate.
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9. Undo 3 x phillips screws and take off regulator.
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10. Replace regulator and cover plate.

11. Refit alt in car, replace alt connectors, fit drive belt, connect battery.

12. Start car and check light flicker has gone, a voltmeter across the battery terminal should give a steady reading of about 14v.
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Success!
 

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MG ZT, Rover 25
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Discussion Starter · #3 ·
Got reg from K Helliker Auto Electrical in Bristol. They couldn't fit it in to the workshop in the time I had available, so I just bought the part and fitted it when I got home - I like to have a go at these things anyway!
 

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When i drove home from work tonight i opened my window briefly and noticed the dash light and the headlights flicker a little bit, would this be because of the same thing? or maybe altenator on its last legs?
 

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MG ZT, Rover 25
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Discussion Starter · #5 ·
Well my symptoms were contant flickering (approx 2 per sec), once the engine was running and setted down. It was evident in all lights, including the clock/ instruments. You could also put a voltmeter across the battery with the engine running and see whether you get a steady 14v (ish). Mine showed a noticable voltage variation with the dodgy reg.
 

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mg_zr
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I'm having the Same issue. Mine starts roughly 10 mins in to driving as the car warms up it seems. So is the regulator in side the alternator?. I'm just thinking if it's easier to get a new alternator and driver belt just in case it's the alternaor it's self. My car is an mg zr tho. Thanks
 

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mg_zs
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I changed my voltage reg about 2 years ago and haven't had any issues since, £22 for a Bosch reg from eBay. I didn't have any problems getting my alternator off as I was able to remove the top mount. Took about 35 mins in total. Worth changing if you are having any problems now before winter sets in which is when the alternator has to work harder due to more use of lights, heater etc.
 

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How did you get on with taking the Alternator off the bottom mounting? Mine has had very noisy bearings in it for the whole time I have owned the car, so I do want to replace it before it fails - only problem is that the lower mounting on my car just spins and spins - there doesn't seem to be any way to undo it... Any ideas?

Wigster.
 

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rover_400_95_99
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How did you get on with taking the Alternator off the bottom mounting? Mine has had very noisy bearings in it for the whole time I have owned the car, so I do want to replace it before it fails - only problem is that the lower mounting on my car just spins and spins - there doesn't seem to be any way to undo it... Any ideas?

Wigster.
The bolt head is supposed to be captive in the casting, but like yours, mine just turned and it is impossible to access. I eventually used a mini hacksaw on the nut together with a sharp chisel to split it. New nut and bolt from local hardware store and job done.
Crude but effective.:)
 

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MG ZT, Rover 25
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Discussion Starter · #11 ·
How did you get on with taking the Alternator off the bottom mounting? Mine has had very noisy bearings in it for the whole time I have owned the car, so I do want to replace it before it fails - only problem is that the lower mounting on my car just spins and spins - there doesn't seem to be any way to undo it... Any ideas?

Wigster.
Talking zs, I didn't have too much problem with the alternator bottom mount, iirc I wedged the nut. With a/c, the alternator is quite tight in the engine compartment and I had to loosen/ move away a few things.

George, I think it would be difficult to remove the regulator with the alt in place (I would have done it if I could).

Wigster has a good point; if the alt is tired you might as well replace the whole unit with a reconditioned one and get new bearings in the front end as well as the regulator at the rear.
 
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