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Triumph TR6 - High voltage..

High folks,
iteresting weekend I had. The weather was awesome so I took out the TR6 and had fun. Well I was driving home Sunday night after dark (my wife hates that) so on came the lights. I was a hour from home. About 10 min from home my dash went dim, and apposing trafic was flashing me that I was with out head lights. Long story short the "Old Car Gods" were on my side. It died on me as I crawled my front tire on to my driveway. I pushed it into the garage and left it to the morn.

In the morning I discovered my Alternater is a GM, a 48 amp. It didnt have a fielded cable sending a signal to recharge batery (????) dont ask me how I have been driving all this time on pure battery power. (sounds like a comercial for "Die Hard") I rarely turn head lights or blower fan on. I guess the coil is the only thing drinking. So I put a proper GM cable to field it and it is indeed now charging.

My problem: It seems to charge the battery at 15 volts. I feel thats a little high. Is this due to the amperage or the type of Alternater (GM)....or should I not worry and accept it as being safe??

I thank you in advance for reading this lengthy borring tid bit.

PS, To all our Florida friends be safe and get back to us we are all thinking of you.

15 volts does seem a bit high, I'd be looking for 13.5/14v. approx, it might settle down a bit once the battery's been fully charged.
R. Algie

Thats what I thought. I am waiting to see if it will settle down if not I will need to crack open or replace the unit.
Marcello..(I am a memeber)


With no loads on, the alternator voltage should be around 14.5. With all loads on, it should not drop below 13.5. 15 volts is a bit high, but it could be your voltmeter isn't accurate. Measure it with a good shop meter and see what it is.

Dan Masters

I measured it with a a few meters. All read some where around 15...... one read @ 14.75 ish

I just want to know if this is heavy and if it will end up frying the battery. With lights it does go down to 14...and if I run the blower fan 13 ish.

Does a GM alternater talk the same language?

Hi Marcello

What alternator are you using? Delco#

It is a 3 wire not 1 wire industrial?

Take it into partsource or any of them for a free check. Have the battery checked at same time. Take it to a couple unless you know them? Some tend to have lets sell them something results in TO I hear?

Most all Delco have a 5 year guarantee now due to past problems with rebuilds. Many of the parts places will replace without a receipt. I have had problems with a few. But new ones seem OK now.


Bill Brayford

all done
Bad regulator in alternator...had the whole thing rebuilt, after many quotes the best rate was $60.00 and all is fine today. Running at 14.4 volts. Sorry all you original parts people it is a GM, and for the reason that all advised me to stick to it for reliability. It is one item that should be kept modern like brakes. Plus my research shows that most of the versions that Triumph instaled were not very good. (lucas or the Bosch)
Cheers all...

Ok sorry, I should have mentioned Delco-Remy is a division of GM? Thought everyone new that? GM means Delco!

Its a classic example of the problem units and would have cost $00. If returned to any dealer or parts place as I stated. Depending on # mind you.

The comparable Bosch units are much more reliable since there agressive campaign with parts lately. Since I don't know what unit your running they may or may not make a repop?

Charge your battery to a minimum rate as well. You will burn out that alternator fast. If you have a number of killed battery's.

You seem to have all the answers. Have a nice day. BWOT.


Bill Brayford

Ok,.....its now charging at 15...AGAIN!!! ????
I am totaly lost. I had the thing rebuilt. Is it the amperage? Does it realy matter what kind is on there? Dont they all basicaly do the same thing?.....Does anyone have Idea? Can it be that my battery is needy? Its a Die Hard maintance free.

Will someone tell us all if this 1/2 volt overcharge is worth worrying about?

This thread was discussed between 06/09/2004 and 12/09/2004

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