Battery Warning Light - permanently on !

[Penelope Stopit]

Are you able to see the alternators rotor through its casings front or rear air vents? You could possibly put a dab of paint on something to see if its moved after cranking

Is there any access to the warning light terminals nut at the rear of the alternator?

Can you reach the alternator positive terminal and make contact with it by using a long thin insulated screwdriver or long thin screwdriver covered with insulation tape?

[FarmyardPants]

Mr Cerbera said:

FarmyardPants said:

That's ok.

Paul, let us know what the voltage is across the battery with engine running, assuming it still starts

Before Starting: Volts across Battery (to engine earth) = 12.33V
When idling ~ 900 rpm = 11.96V

From my 'standing next to wing' view I can't see the alternaror pulley moving

BUT
I can't see the engine pulley moving either

Am gonna try to see summat more with an endoscope cam.
Have taken my necktie off (just in case).

Wish me luck

Probably/hopefully the big fuse then, otherwise your alternator might be goosed. I would disconnect the battery before you start (be careful to avoid touching anything metal with the spanner if you remove the +ve lead). The fuse may look ok, as others have said they can develop cracks. It's an idea to smear the washers with a bit of copper slip, otherwise the action of doing up the nuts can tear the fuse blade. It's an awkward job but not too bad, use a torch .

[FarmyardPants]

Thread with pics of the fuse location here:

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Mr Cerbera]

Thanks for that, Rog

I realise that this is old news for most of you guys

BUT

Just in case there is someone out there who might need this in the future...

Once I'd taken the inlet manifolds off I was faced with this (taken from the passenger side)



After a bit of jiggery-pokery (and some heavy leverage) guess what I found !



Thanks for all your dvice, Guys

Will re-attack (with new back) tomoz

[Penelope Stopit]

Nice find

[Mr Cerbera]

stBuggerbdPissfkFart

It's NOT the Big Fuse
BUT
I have found it AND it's a beautiful 125A one

Guess I'll have to pursue the 'Alternator Drive Belt' theory.

Oh Well, Fuel Rail off twice in 15 months has to be some sort of record.

Ooops, don't forget to order those O Rings

Have a great Grand Prix and Sweden-crushing match All

[ukkid35]

Mr Cerbera said:

stBuggerbdPissfkFart

It's NOT the Big Fuse
BUT
I have found it AND it's a beautiful 125A one

Guess I'll have to pursue the 'Alternator Drive Belt' theory.

The fuse doesn't seem to 'fail' completely every time

If you ever find you have a bouncy rev counter, the battery will probably still be charging, but replacing the fuse will fix the rev counter

It seems they can break down without preventing the battery from charging

[gruffalo]

Other causes can be the lead from the alternator to the fuse and the fuse to the battery, I had similar and it was the cable at the alternator end loose in the crimp connector.

You mention what the battery voltage is before starting and after at idle but what is it with the engine revving and then what is it with a load like headlights or rear window turned on? Knowing these will help diagnosis hugely.

[Mr Cerbera]

ukkid35 said:

The fuse doesn't seem to 'fail' completely every time

If you ever find you have a bouncy rev counter, the battery will probably still be charging, but replacing the fuse will fix the rev counter

It seems they can break down without preventing the battery from charging

Thanks Paul

As I haven't suffered any other intermittent electrical failures, I'm tempted to think TBF is still strong
combined with the fact that the Battery charge was lower whilst the engine was running pushes me in
the direction of a failing alternator (perhaps falsely).
I think I will rip off the fuel rail and have a look at the drive (which I am a little suspect of, now that I have
seen a pic of the 10PJ432170J drive belt).

I sent you a mail asking if there are any "Dos or Donts" about replacing the drive belt.

Just trying to access one at short notice, on a weekend, in a catholic country, might be my downfall

WML

[Mr Cerbera]

gruffalo said:

....You mention what the battery voltage is before starting and after at idle but what is it with the engine revving and then what is it with a load like headlights or rear window turned on? Knowing these will help diagnosis hugely.

Thanks G

I was going to write "I guess I'll have to pay someone to be a friend and push on the gas while I read the meter "
when I just realised that I can jam the linkage open from under the bonnet whilst holding the meter !

You're a STAR !

Results tomoz !

[Chuggaboom]

Mr Cerbera said:

I'm tempted to think TBF is still strong
combined with the fact that the Battery charge was lower whilst the engine was running

I was told, IIRC, by someone who builds many engines and is well known in the TVR world that the AJP alternator set up, coz of the pulley sizes, doesn't produce any useful charge untill over 1800 rpm.

[Mr Cerbera]

Firstly, many thanks to ukkid35 for your mails, most appreciated

Secondly, Current st level: Over my mouth, underneath my nose

Managed to find twinkam's part no on the alternative parts list

Went to my local autofactors "Nothing exists for that width/length ratio !"

Searched on TVRParts and found that they specify different belts for the 4.2 and 4.5 motors ~ £22
so
Very glad that I didn't come away with the wrong belt

Unfortunately, for the umpteenth time, my order at TVRParts failed with
"VALIDATION ERROR - Invakid request - See details"
and there were, of course, no details.
________________________________________________________________________________________

So, 2 questions:

1) Has anyone ever successfully completed an order using the TVRParts website ?
I know that they've lost £600 on orders from me alone !

2) Has anyone ever replaced their Alternator Drive Belt on a 4.5 ?
If so, where did you get it from and (fingers crossed) what was the part no ?

Thanks all
________________________________________________________________________________________
ETA
Have found one from RaceTech, thanks
Interesting to find from TVRParts and RaceTech that there are two belts available.

4.2 Part No. E2121
4.5 Part No. E2943

Edited by Mr Cerbera on Saturday 7th July 13:28

[Mr Cerbera]

Chuggaboom said:

Mr Cerbera said:

I'm tempted to think TBF is still strong
combined with the fact that the Battery charge was lower whilst the engine was running

I was told, IIRC, by someone who builds many engines and is well known in the TVR world that the AJP alternator set up, coz of the pulley sizes, doesn't produce any useful charge untill over 1800 rpm.

Interesting statement Chugga
BUT
Methinks that the Warning light has come on for a reason

[Rufus Roughcut]

When I wanted to carry one as a 'spare' the guys at the shop told me " just because yours is a 4.5 doesn't mean a 4.5 belt will fit!" I bought one of each.

Wishing you the best.

[Mr Cerbera]

Rufus Roughcut said:

When I wanted to carry one as a 'spare' the guys at the shop told me " just because yours is a 4.5 doesn't mean a 4.5 belt will fit!" I bought one of each.

Wishing you the best.

Cheers RR

Ha Ha ! That is such a classic TVR Supplier situation.

I have now ordered two, from different suppliers, neither of which promises to make my deadline so I will be interested to see what arrives (and when).

Thanks for your wishes

BTW Did you actually install a belt ?
I have heard that you have to unbolt the Alternator from its retaining plate and then try and poke and jiggle the belt on.
What sort of tensioner is used ?

Many thanks,

PJ

[FarmyardPants]

Hi Paul, before you go to all that trouble, have you ascertained that the belt is shot/the alternator isn’t rotating? You said earlier that you couldn’t see it, but you also couldn’t see the drive pulley rotating..

Edited by FarmyardPants on Saturday 7th July 21:26

[TwinKam]

Alternator pivots on one side by a long bolt which runs through a tube, and is fixed on the other by a bolt which moves through an arc shaped slot in the mounting bracket. Very old skool but uncomplicated by springs and rollers.
You would need to slacken both the pivot bolt and locking bolt to move it, levering the alternator body upwards to tension the belt whilst you tighten first the locking bolt and then the pivot bolt.
How much tension on the belt? Difficult to describe... but using moderate effort on the lever. As the belt is so short for its width, it will be actually quite difficult to over tension it.
Here's a pic I found of the bracket:
https://m.ebay.co.uk/itm/TVR-AJP-V8-Alternator-Bra...

[Mr Cerbera]

FarmyardPants said:

Hi Paul, before you go to all that trouble, have you ascertained that the belt is shot/the alternator isn’t rotating? You said earlier that you couldn’t see it, but you also couldn’t see the drive pulley rotating..

Edited by FarmyardPants on Saturday 7th July 21:26

Hi Rog

Sorry about that. I became a little distracted when I was trying
to make the endoscope work on a Windows XP Notebok
BUT
after I threw that idea in the bin, I used the tried-and-trusted old engineers
trick of sticking summat in it whilst it was turning
and, low-and-behold, the engine pulley was spinning away like a good 'un whilst
the alternator was still as ........ ummmmm, where's the "can't think of a good metaphor"
smilie

BUT

Thanks fo reminding of it

[Mr Cerbera]

TwinKam said:

Alternator pivots on one side by a long bolt which runs through a tube, and is fixed on the other by a bolt which moves through an arc shaped slot in the mounting bracket. Very old skool but uncomplicated by springs and rollers.
You would need to slacken both the pivot bolt and locking bolt to move it, levering the alternator body upwards to tension the belt whilst you tighten first the locking bolt and then the pivot bolt.
How much tension on the belt? Difficult to describe... but using moderate effort on the lever. As the belt is so short for its width, it will be actually quite difficult to over tension it.
Here's a pic I found of the bracket:
https://m.ebay.co.uk/itm/TVR-AJP-V8-Alternator-Bra...

Hi Rik

Thanks for all that info.
I'm sure when it's all in my hands that it will mean summat

[Mr Cerbera]

Now I'm sure that summat should be on here....


"Dear Mr. Phelps/Hunt" ((Depending on your age)
"This tape will self-destruct in 102,000 miles"





I can't believe that I am so lucky.
Of all the places that we've travelled to, this happened 10 mins from home.

"I musta done somebody some good"

Edited by Mr Cerbera on Monday 9th July 15:17