V8S 1991 what size alternator?

[mjjryan39]

I'm new to the world of S's and I know there are many threads out there on this topic and i've tried to do some research but no answers. I have a perm battery warning light on and my volt meter is constantly in the red and jumps up and down when the indicators are on. A good guess would be a shot alternator but which one? 65amp? Also i think i have a pre-serp engine as only have two things on the belt Alternator and water pump. so again my assumption would be lower amp alternator needed. Also i don't want to fry any other electrics any advise?

[phillpot]

All V8s's are "pre-serp".....should have a V belt rather than a flat ribbed belt?


65 amp should be ample for the small demands of an S as opposed to all the electrical needs of a Range Rover but a larger amperage unit will do no harm.

[Penelope Stopit]

After solving the alternator problem, there is a very good chance that the voltmeter will still flicker with the indicators due to volt drops throughout the supply and return cables,connectors and fusebox
I attach a diagram that will give you true battery voltage readings at the voltmeter as long as the meter is in good order

[mjjryan39]

phillpot said:

All V8s's are "pre-serp".....should have a V belt rather than a flat ribbed belt?

yes after checking it is a V belt

65 amp should be ample for the small demands of an S as opposed to all the electrical needs of a Range Rover but a larger amperage unit will do no harm.

any recommendation on a good one to get?

[phillpot]

mjjryan39 said:

any recommendation on a good one to get?

I presume it's a "hobby car" mere couple of thousand miles or so a year? Any "old thing" should do

[mjjryan39]

phillpot said:

mjjryan39 said:

any recommendation on a good one to get?

I presume it's a "hobby car" mere couple of thousand miles or so a year? Any "old thing" should do

I may take my wife to Nando’s but my ‘S’ goes to the Ritz...any old thing simply won’t do.

[mk1fan]

You could upgrade to a 100amp unit. Would mean swaping the pulleys to ribbed versions.

I'm doing it on the Wedge as I want to swap to a electric hydraulic pump for the power steering.

[zombeh]

There are several different ones for the rover v8 depending on what else was fitted to the front of the engine, most of the ones that show up in that ebay link are the wrong way round.

As I get less young I get lazier with working out which bits are from what and trying to decipher exactly what someone on the internet is selling (as they generally have no idea) and when mine made horrible broken noises last week I just ordered https://tvr-parts.com/tvr-parts/part-details/tvr-e...
You may (will) have to use the spacers off your old one to get the pulley in the right place and you will find the belt tension hole is threaded where it probably isn't on yours but that's two seconds with a drill to sort.

[Barkychoc]

You could try changing the brushes and rectifier unit first - it's really easy to do and they are under a tenner on fleabay.

[mjjryan39]

In prep for getting a new one i’ve heard there are issue with the belt tensioner so bought one of these:
Adjuster Alternator Belt Tensioner Bracket Kit Car Project Special Rover V8 TVR https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2...

[mjjryan39]

zombeh said:

There are several different ones for the rover v8 depending on what else was fitted to the front of the engine, most of the ones that show up in that ebay link are the wrong way round.

As I get less young I get lazier with working out which bits are from what and trying to decipher exactly what someone on the internet is selling (as they generally have no idea) and when mine made horrible broken noises last week I just ordered https://tvr-parts.com/tvr-parts/part-details/tvr-e...
You may (will) have to use the spacers off your old one to get the pulley in the right place and you will find the belt tension hole is threaded where it probably isn't on yours but that's two seconds with a drill to sort.

Awesome thanks zombeh i’ll get one of those.