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Richrd
Richrd
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Randy M Offline OP
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Mine has never had one for either the starter or the large solenoid beside it (the relay or small solenoid in the left panel has a thin red ground wire connected). Am re-reading an article in the Triple Echo issue 223 where Tim Riley talks about where the (thick) ground wire can be attached to the frame but it does not mention where it attaches to the starter. Given mine has worked for years (I think current problem is the solenoid) is it necessary?
Randy M Western New York + Toronto

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Originally Posted by Randy M
Am re-reading an article in the Triple Echo issue 223 where Tim Riley talks about where the (thick) ground wire can be attached to the frame but it does not mention where it attaches to the starter.

There is no "thick" (or other) "ground wire" that attaches directly to the starter or solenoid as they ground through the starter motor housing but there must be a heavy gauge cable already attached to the battery positive terminal so what or where does that heavy gauge wire connect (cylinder head? Engine mounting?) as that is the "(thick) ground wire" mentioned.
There seems no logical reason for it to be attached to the "frame".

Last edited by L.A.B.; 09/13/21 11:02 pm.
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According to the 1975 diagram that I have, the thin white/red wire connected to the solenoid next to the starter motor is the solenoid power which comes from the relay C2 terminal. A brown/blue wire connects the C1 relay terminal to the heavy black wire on the starter motor which comes from the battery negative terminal.
I am not sure where they put the battery positive wire but i would use a longer than standard 5/16" bolt in the upper rear of the clutch housing and use the end sticking out next to the starter as the attachment point.
Attaching it to the head you have the 200+ amperes of the starter going through the case bolts (if the joints are effectively isolating the parts) and going to the frame you have to clean off the paint from the engine mounting to get a good connection.

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The positive battery "earth" on the T160 seems to have been connected to the frame in at least two locations.
Of my four T160s two are connected in one location and the other two in a second location.
No reason to suppose that they were not original locations----it is not the sort of thing that you change out on a whim!
Probably depended on which fitter did the assembly.
The first location is shown in the first photograph and the terminal (an L terminal) bolts to the rear of the bolt holding the rear plate to the frame.
The second location is shown in the second photograph and the terminal was bolted to the rear of the top bolt holding the rear chaincase to the rear plate.
HTH.

T160 Battery Earth 1.jpg T160 Battery Earth 2.jpg
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Originally Posted by Tridentman
The positive battery "earth" on the T160 seems to have been connected to the frame in at least two locations.

I believe the cylinder head was the original location.
"Ground wire to Cylinder Head":
[Linked Image from i.postimg.cc]

I attach it according to the information in section B1 of the T160 Manual (engine removal) "Remove the bolts holding the right side engine plate and footrest...Note that a ground (earth) cable connection is located under the nut of the top bolt. It is most essential that this connection is replaced on re-assembly using a new self locking nut.".

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Sounds as though "anything goes" or "anything went" in terms of the positive wire location on the engine/frame.
Probably not surprising as these bikes were built in the death throes of NVT.

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On mine the main ground cable goes from the battery POS to the top left of the cylinder head. Based on my VIN I have one of the earliest T160's (but so far no hint of the steering head or Kick Stand breaking off). Once I forgot to hook this up and indeed the thinner wires were carrying all the ground and started to burn up. Of course I then installed the ground cable but I later discovered that its connection to the cylinder head was loose. So I remedied that but I'm now thinking I should install an auxiliary ground.
Should it be from the starter motor casing to either of the two locations Tridentman nicely provided? Where on the starter should I start this wire? I noticed that in the casting that is between the starter motor and the inner primary case there is a mystery hole drilled and tapped (about 5/9" diameter) and it has a rubber plug over it for some unknown reason so maybe I can just attach the extra ground wire from the Tridentman locations to there? Seems a bit redundant to wire from a casting to a casting/engine bracket. Should I instead run the auxiliary ground wire from a Tridentman location to the battery POS terminal?

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I don't think the extra wire is strictly necessary but on the other hand it can do no harm.
If you want to install an auxiliary wire then I would certainly connect it to the battery positive terminal with the other end to an engine casting.
However -- as you have found---making sure the existing wire is properly installed is the first priority.
Your post is particularly pertinent to me as I have just had a similar experience with my Ural sidecar outfit.
It suddenly cut out without warning and I eventually tracked the fault down to the negative battery terminal being quite tight but not tight enough (it is a negative earth bike)
When you have an electric starter you have perhaps 200 amps going from (and to) the battery compared with just say 10 amps with a kickstart bike so the terminals have to be super tight otherwise you do not get sufficient current to start the bike.
Personally I would stick with your current wiring (no pun intended!) and make sure that the connections are super good.
HTH and best of luck!

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Originally Posted by Randy M
On mine the main ground cable goes from the battery POS to the top left of the cylinder head.

Once I forgot to hook this up and indeed the thinner wires were carrying all the ground and started to burn up.

That is the reason for not having a harness wire connected to the battery positive terminal as stated in the service bulletin so if you have one fitted now then it's better to remove it.


Originally Posted by Randy M
Of course I then installed the ground cable but I later discovered that its connection to the cylinder head was loose. So I remedied that but I'm now thinking I should install an auxiliary ground.

There shouldn't be any need for an "auxiliary ground" as long as the connection remains tight (self-locking nut?) or move the existing cylinder head ground cable closer to the starter motor.


Originally Posted by Randy M
Should it be from the starter motor casing to either of the two locations Tridentman nicely provided?

Why not just move the existing cable to (or closer to) the starter motor? An additional cable running from the starter motor to one of the previously mentioned locations makes no sense unless the ground cable to battery positive is also connected there.

A ground to the frame only (as one seems to be) not including part of the engine case would be a step in the wrong direction in my opinion.


Originally Posted by Randy M
Where on the starter should I start this wire? I noticed that in the casting that is between the starter motor and the inner primary case there is a mystery hole drilled and tapped (about 5/9" diameter) and it has a rubber plug over it for some unknown reason

I don't know of any 5/9"(!?) diameter tapped hole with a rubber plug in the starter motor housing.

Edit: The casting has a boss on the top with a 0.4" hole to take the rubber bung that supports the airbox but it wouldn't normally be tapped.
https://www.triumph-spares.co.uk/rubber-buffer-82-7835

Originally Posted by Randy M
so maybe I can just attach the extra ground wire from the Tridentman locations to there?
Seems a bit redundant to wire from a casting to a casting/engine bracket. Should I instead run the auxiliary ground wire from a Tridentman location to the battery POS terminal?

If you attach a ground wire to the starter motor then the logical thing to do would be to connect it to the battery(+) then you wouldn't need the existing ground wire.

Last edited by L.A.B.; 9 hours ago.

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