Page 1 of 1

Alternator issue

Posted: 12 May 2014 11:04
by UKPhilTR7
A bit ago, I took my TR to the garage to have some work done on her. When she came back I noticed that the battery light was on, when the car was running. This was not the case before and a friend told me that it may of been due to the fact that some welding may of been done without disconnecting the battery.

So I took it off and put the old one back on. This has been the situation now for about a year or so. However, now I want to fix the newer alternator and put it back on the car. It had done less than 500 miles before the light came on all the time.

I have never looked into it too deep, but could anyone give me some pointers on what to look for and how I can fix this as it would be a shame to throw it away.

Image Image

Posted: 12 May 2014 15:05
by dursleyman
If they did welding without disconnecting the battery it will most likely have blown the diodes in the alternator. I am fairly certain I have seen advice on how to test them on this forum somewhere.
You can get new diode packs for most common alternators and they are easy to fit.

Russ

1980 TR7 Sprint DHC, 1981 TR7 Sprint DHC
Dursley
UK

http://tr7russ.blogspot.co.uk/

Image Image[img]http://i1040.photobucket.com/albums/b410/dursleyman/TR7%20web%20picture/IMG_0479-Optimized.jpg[img]

Posted: 13 May 2014 23:17
by UKPhilTR7
Thanks for that, I have heard it may be the diodes and that is the first thing that I am going to look at, then go from there.

I have taken it off the car to have a closer look and mine looks like the one in the Rimmer website. I have taken the black cover off and can see the voltage regulator. It looks like the regulator is sealed, would I he right in thinking that the diodes are in there?

I brought mine from S&S as an uprated one, but I do not know the ACR rating of it, so I can get the correct regulator, if I buy a new one. On the Rimmer site they sell regulators for the 17 ACR, but I am thinking this may be no good to me if my ACR is higher than 17.

Is there a way I can find out the ACR rating of my alternator, as I cannot see any markings on it or would it say on the regulator when I take it out and have a closer look?

Image Image

Posted: 14 May 2014 11:06
by UKPhilTR7
I took the regulator off and it has only two wires coming from it, black and yellow and the number is VR-LC100. On the regulators in Rimmer there are four cables Yellow, Black, Red and White.

Still no sign of the rating of the alternator on it anywhere. I did hear that there is a way I could tell the rating by counting the number of rings on the centre black partition, but no idea how.

Shooting in the dark here, is this the diodes here:
http://www.rimmerbros.co.uk/Item--i-517231

Or this here:
http://www.rimmerbros.co.uk/Item--i-BAU5264

Image Image

Posted: 14 May 2014 13:48
by DutchTriumph
Diodes are in the rectifier


Cheers,
Peter

1977 TR7 FHC, 1976 Spitfire 1500

Posted: 14 May 2014 21:25
by UKPhilTR7
Thanks for that later last night after looking at it for some time I was starting to think that too and they are easier to get to as the regulator is factory sealed. I can get one of these as they are cheap enough.

The issue now is how can I tell the rating of my Alternator when there is no visible signs on it?

I heard that a 36 amp is classed as 17 acr and a 43 amp output alternator is classed as 18 acr. This is all good, but when it is not on the car, it is a bit hard to verify. My issue is that there is no markings on the alternator itself. If I was to put a 18 acr rectifier on a 17 acr alternator, would this create a big issue?

Image Image

Posted: 15 May 2014 07:04
by Cobber
Phil just bin the damned Lucas POS and get a Bosch, I can't remember where the Bosch alternator in mine came from (too long ago) I'll ask my auto electrician mate he might remember.

"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"

80'Triumph TR7, 73'Land Rover (Ford 351. V8),
'89 Ford Fairlane
'98 MG-F, 69'Ford F250.

Posted: 15 May 2014 21:17
by UKPhilTR7
I must admit cobber it is looking more and more like I will have to get another one. Next time I will tell the garage to disconnect the battery. I did find out that it was an 18 acr. If you could get the number or name of a bosh one that will diff our connections or can be made to with minimal work, I would be more than happy to get it :)

Image Image

Posted: 17 May 2014 02:52
by scarface031
The good news is you get 6 free diodes along with a new alternator ;)

-Justin P

Posted: 17 May 2014 10:55
by UKPhilTR7
Oh yes you are right lol
I have decided to go and buy another one. The cost of getting a new one compared to trying to fix the old one, I just thought that it is not worth my time :) Maybe the easy option, but there is too much work to do on my car as it is, without making things harder and longer than they need to be for a few pounds lol

Image Image