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Battery Bafflement

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nmjworkman Nathan Workman
Conover, NC, USA   USA
Hello all!

I recently purchase a 1974 Triumph TR6. When I bought it, there was significant battery corrosion, and the positive terminal had to be cleaned in order to get it to start. Changing out the positive lead cable was on my list of projects to knock out.

This morning, I tried to start the car, and it would crank, but not turn over. I checked the battery, and again, the positive terminal had corroded significantly, so I decided it was time to change it. Here is the process I followed:

1) Removed negative battery lead.
2) Removed positive battery lead.
3) Disconnected positive battery lead one cable at a time, and the connection I removed I installed on the replacement positive lead.
4) Purchased new battery from Autozone (took the old one in and they gave me a direct replacement).
5) Connected positive battery lead.
6) Connected negative battery lead.

At this point, I turned the key to start the car, and all it attempted to crank and then cut off. I saw a small puff of smoke, and turned to see that the negative battery lead had melted and the cable was extremely hot. I checked three times and can't see any place where the negative or positive leads were any different than when when I had bought it. I am concerned about reconnecting the negative battery lead and attempting to restart, so are there any ideas of what could be wrong?

(I'm a total Triumph neophyte by the way, but I do love them and don't want to destroy the one I just bought).

Thanks in advance!

-Nathan

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dicta dick Taylor
Downey, Callifornia, USA   USA
In reply to # 1511250 by nmjworkman Hello all!

I recently purchase a 1974 Triumph TR6. When I bought it, there was significant battery corrosion, and the positive terminal had to be cleaned in order to get it to start. Changing out the positive lead cable was on my list of projects to knock out.

This morning, I tried to start the car, and it would crank, but not turn over. I checked the battery, and again, the positive terminal had corroded significantly, so I decided it was time to change it. Here is the process I followed:

1) Removed negative battery lead.
2) Removed positive battery lead.
3) Disconnected positive battery lead one cable at a time, and the connection I removed I installed on the replacement positive lead.
4) Purchased new battery from Autozone (took the old one in and they gave me a direct replacement).
5) Connected positive battery lead.
6) Connected negative battery lead.

At this point, I turned the key to start the car, and all it attempted to crank and then cut off. I saw a small puff of smoke, and turned to see that the negative battery lead had melted and the cable was extremely hot. I checked three times and can't see any place where the negative or positive leads were any different than when when I had bought it. I am concerned about reconnecting the negative battery lead and attempting to restart, so are there any ideas of what could be wrong?

(I'm a total Triumph neophyte by the way, but I do love them and don't want to destroy the one I just bought).

Thanks in advance!

-Nathan

Nathan --- I don't know if it's your only problem, but the negative battery needs a heavy wire attached to both the engine block (or head) and to the body of the car. I see only a thinnish red / black wire. The setup you inherited may not have been ideal, and you copied it.

Dick

barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
What Dick said. Also, please explain your step #3 in more detail.

Was this TR6 running when you bought it? You actually drove it?

EDIT I just noticed what appear to be a couple of 'fried' wires lying beneath the bonnet latch, possibly a white and a brown. Whats up?



Edited 1 time(s). Last edit at 2018-02-03 05:38 PM by barry s.

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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
Looks to me like the clamp to the (aftermarket) battery cutout is actually broken, and the main ground wire is missing from it. I could be mistaken, but I think it was originally this style of clamp

and it's simply broken. The heavy ground wire is probably laying somewhere; kind of looks like it might be dangling over by the fuel pump. (Ground straps are frequently not insulated and I think I see some wire braid over there.

I don't like that kind of clamp anyway, they are troublesome and rarely last for very long. You can pick one up at any FLAPS to get back on the road, but my suggestion is to order the proper ground cable from TRF (or Moss). As noted above, it should have two terminals in addition to the clamp; one goes to the body and the other to the engine block.
http://trf.zeni.net/TR6greenbook/index.php?zoom=1&page=35

I would also want to trace that small red wire, to see what it does. Pretty clearly added by a previous owner; it may or may not serve a useful purpose.

Once that is all dealt with; only crank it for a few seconds, then stop and feel along the battery cables and clamps. Slightly warm is OK, but if anything is getting hot, there is a problem that should be dealt with sooner rather than later. Starters draw gobs of current (about 500 amps to start, tapering to around 300 once the engine is cranking), so every connection has to be perfect.

It's less common, but it is possible for them to fail such that they draw more current than they should, so if a cable is getting hot along it's length (rather than near a connection), you may have a bad starter. I had one fail on the way to VTR 2000, and it let the smoke out of the battery cable. I just thought the battery was a bit low, until I saw the smoke!



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild



Edited 2 time(s). Last edit at 2018-02-03 07:15 PM by TR3driver.

poolboy Avatar
poolboy Ken D
Sandy Hook, MS, USA   USA
That red wire on the negative battery clamp may be a hot wire that you shorted out by connecting it to the battery ground...If so that's where the smoke came from.

mhbva Avatar
mhbva Marc Botzin
Lorton, VA, USA   USA
1976 Triumph TR6 "Monty"
Nathan:

You have encountered what appears to be what is called a bodge by a previous owner who likely may have made other incompetent and dangerous changes disguised as repairs or improvements. You will be able to recognize how the factory intended most things to be, including the grounding of the battery, with a Bentley manual. Part of the joy of owning a TR is maintaining it as much as possible by yourself. As you have seen, there is always help and guidance available here.

spridgettr Avatar
spridgettr William Kern
Pittsburgh, PA, USA   USA
all of the above good info, that red wire on - post needs to go, and if it is a - for whatever it needs to be black. Your ground wire setup should be like this pic....1 on body 1 on engine block.

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nmjworkman Nathan Workman
Conover, NC, USA   USA
Thanks everyone! This has been extremely helpful.

For Step 3, what I mean is that as I disconnected each wire or bolt connected to the positive lead (there were three wires that connected to the posts on the lead), I connected each wire or bolt on the replacement positive lead to ensure that all of the wires were put in the exact placement as the previous one.

The car was running fine when I bought it; I've driven it for about 20-25 miles without any issue. The previous owner had a number of Triumphs, and mentioned that he had made some modifications to it, but I didn't know enough at that time (or even now) other than to smile and nod my head. He's in very poor health now, and when I sent him a text yesterday, he couldn't remember specifically what modifications he made to the electrical system.

The wires underneath the bonnet latch are the ones that connect to the positive lead in that black junction that have 4 spade connectors. The white and brown ones are going behind the firewall, the connector on the bottom goes to the alternator.

As a follow up, at this point, I've placed a correct negative battery lead (I had a spare) on the car (connected bolts to engine and body ground) and reconnected the battery. When I turn the key, there's a single click but the car isn't trying to turn over. The battery is getting proper voltage, so I'm guessing the problem is elsewhere. I've ordered a troubleshooting manual to see if I can diagnose the issue further.

Thanks again everyone! I'm 34 and new to Triumphs, so I really appreciate the help.

In reply to # 1511272 by barry s What Dick said. Also, please explain your step #3 in more detail.

Was this TR6 running when you bought it? You actually drove it?

EDIT I just noticed what appear to be a couple of 'fried' wires lying beneath the bonnet latch, possibly a white and a brown. Whats up?

spridgettr Avatar
spridgettr William Kern
Pittsburgh, PA, USA   USA
the click is probably from the solenoid on starter, you said you smelled smoke / burning wire....check the wires to starter, the little spade connector on top is always a suspect: loose corroded and you may have fried the wire to the solenoid. It's the brown w blk stripe that's on that relay box on + wire near bonnet latch.....PS that relay doesn't look to be TR ???? hard to tell in pic probably PO mod

save your $ on buying any books most everything is free on line...........wire diagrams manuals etc dowloand and save these

http://tecb.eu/onewebmedia/TR6_repair_manual.pdf

http://www.advanceautowire.com/tr2506.pdf

http://tr6.danielsonfamily.org/6-tech-Manuals.htm



Edited 2 time(s). Last edit at 2018-02-04 03:58 PM by spridgettr.

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rjc157 Avatar
rjc157 ralph c
pearl river, NY, USA   USA
You might have fried the solenoid on the starter do the lights go on

Marksg1 Avatar
Marksg1 Mark Greenbaum
Evanston, IL, USA   USA
1976 Triumph TR6 "Nigel"
Nathan, ditto, the negative ground wire is too thin and the nagative terminal connector looks like a disconnect type, you should have a bolt with a platics top that srews in to complete the connection (I don't see it in the photos). How is the ground wire (strap) connected to the car?



I love the smell of hydrocarbons in the morning.

spridgettr Avatar
spridgettr William Kern
Pittsburgh, PA, USA   USA
In reply to # 1511524 by Marksg1 Nathan, ditto, the negative ground wire is too thin and the nagative terminal connector looks like a disconnect type, you should have a bolt with a platics top that srews in to complete the connection (I don't see it in the photos). How is the ground wire (strap) connected to the car?

As a follow up, at this point, I've placed a correct negative battery lead (I had a spare) on the car (connected bolts to engine and body ground) and reconnected the battery. When I turn the key, there's a single click but the car isn't trying to turn over. The battery is getting proper voltage, so I'm guessing the problem is elsewhere. I've ordered a troubleshooting manual to see if I can diagnose the issue further.

NHinNC Avatar
NHinNC Larry C
Greensboro, NC, USA   USA
If you are only getting a click when trying to start, usually one of 3 things.
1- low battery. check voltage on battery. a full battery should be about 12.6 V. Less means battery is not charged. Google "State of charge" to see percentage of charge.
2- bad connections. A starter takes a huge amount off current. Even a small resistance in a connection can cause problems. You have replaced the batter and reconnected some cables. Did you properly clean the terminals? Are you sure of your connections? Make sure that the ground cable has good connections to the body and the engine, as well as at the battery. Make sure the heavy cable at the starter has a good connection.
3- Bad starter/ solenoid.

The reason your small cable got hot, was that there is a large amount of current going to the starter. Small wires have more resistance than large wires, and so that resistance heats up. That is how a tungsten light bulb works.



1976 TR6 Mimosa Yellow - not original
Purchased July 2015

grubscrew Avatar
grubscrew grub screw
The suburbs of, Winfield, Maryland, USA   USA
Correct voltage at the battery does not necessarily mean it has enough charge to crank the engine. My guess is the battery is weak and needs to be charged up (yes, even if it's a new battery).
I'd put the charger on for a few hours or overnight. If you don't have a charger you can push start the car and then drive it to let the alternator do the charging.



Dave
1970 Spitfire Mk3
FDU 78359L
34/11 (Jasmine yellow/Black interior)

1962 Triumph TR3B
TCF 575L
Signal Red/Red interior

Tote Tony M
Kingston, ON, Canada   CAN
Looks like you have an aftermarket gear reduction starter in place. Normally these are reliable units and draw less current load than the stock Lucas units. As others have stated some of your wiring there looks dodgy (old and worn out, not Mopar). Your battery cables have to be the smallest gauge wiring I've seen, except for a motorcycle maybe.

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