TR2/3/3A Grounding problem

R

Redoakboo

Jedi Warrior

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• Nov 14, 2020

• #1

I got my TR-2 back from the garage with a list of things to do, most of which I have finished.

New problem: I had it started and the shop had it started. Now, when I push the starter button, it goes thunk and the ignition light goes off. The battery cables are tight. My neighbor thinks the ground strap from the battery should go to the engine? I had it on the frame when it started for me?? The big ground strap is running from the engine to the frame?

Any ideas?

 

CJD

Yoda

Online

• Nov 14, 2020

• #2

Ground goes:

1) Positive battery to firewall.
2) From the body through the body to frame mounting bolts, which must have at least one bolt to bare metal to make a contact with the frame.
3) Frame at the left engine mount to the engine block.
4) Starter to block.
5) Starter main terminal to the solenoid.
6) Solenoid to the negative battery terminal.

Any one of these connections can and has caused issues for posters in the past.

 

OP

R

Redoakboo

Jedi Warrior

Offline

• Nov 14, 2020

• #3

John,
My car is a negative ground car. It is as follows.

1)Negative terminal to firewall.
2) I don't understand this one?
3) O.K.
4) O.K.
5) O.K.
6) Solenoid to positive battery terminal

When I try to start it now, I'm getting sparks at the negative terminal/firewall connection? Never did this when I first started it It fired right up and ran for 10 minutes?

 

poolboy

Yoda

Offline

• Nov 14, 2020

• #4

Every thing else works ?
Headlights, Horn, Wipers, Brake lights...if so it might be a starter problem.

 

OP

R

Redoakboo

Jedi Warrior

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• Nov 14, 2020

• #5

When I first started it, it fired right up and I ran it for 10 minutes. It went to a brit Shop where they were going to look things over for things I neglected. Now that I have it back, when I hit the starter button, it goes thunk and the ignition light goes off. When I tried to start it with the solenoid, I saw sparks at the negative battery terminal connection to the firewall.

Dick

 

S

sp53

Yoda

Offline

• Nov 15, 2020

• #6

Removing the spark plugs is easy and with them out you should be able to turn over by hand more easily to see if the starter is stuck. In addition, look at the plugs for discolor for future reference.
steve

 

OP

R

Redoakboo

Jedi Warrior

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• Nov 15, 2020

• #7

Thanks Steve,

removing the plug beats removing the starter!

Dick

 

CJD

Yoda

Online

• Nov 15, 2020

• #8

Redoakboo said:

When I first started it, it fired right up and I ran it for 10 minutes. It went to a brit Shop where they were going to look things over for things I neglected. Now that I have it back, when I hit the starter button, it goes thunk and the ignition light goes off. When I tried to start it with the solenoid, I saw sparks at the negative battery terminal connection to the firewall.

Dick

Click to expand...

And that's why I don't let anyone touch my cars. Best case they give it back with more issues. Sky is the limit for the worst case.

So I assume you no longer suspect a ground problem.

Try turning the motor a few degrees to make sure the starter is not locked against the ring gear.

 

F

Frank Canale

Jedi Warrior

Silver

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• Nov 15, 2020

• #9

Sparks at the negative battery to firewall connection indicates high current draw or a bad connection. I would remove and check the connection where the sparks are coming from. Frank

 

OP

R

Redoakboo

Jedi Warrior

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• Nov 15, 2020

• #10

John,

it a very reputable shop that many of the guys in our club go to. They looked it over for about a week and gave me alist of 5 things I needed to address; no charge! I am taking the plugs out this morning and see if i can turn it around.

Dick

 

Merlin63Tr4

Jedi Trainee

Offline

• Nov 15, 2020

• #11

Redoakboo said:

When I tried to start it with the solenoid, I saw sparks at the negative battery terminal connection to the firewall.

Click to expand...

You should not be seeing sparks at any junction.
Undo the negative firewall battery terminal, clean the battery terminal and make sure the lug to cable joint is tight.
Clean the firewall grounding pad, make sure the bare metal is clean and bright.
Reattach the negative ground terminal to the firewall and make sure that it is tight.
Try starting again.

M.

 

S

sp53

Yoda

Offline

• Nov 15, 2020

• #12

I would assume you have the boom shell looking starter on a tr2. If you have, there is a square shape at the end of the armature of the starter; sometimes under a tin cap that removes and you can fit a wrench on the (7/16 I think) square and turn the starter free. Hopefully you installed a new ring gear. If not those starters will stick easily and even with a new ring gear sometimes if the starter is sloppy. The engine shuts off usually in one of 2 places on the compression stroke on the ring gear, so there are about 5 teeth that get hammered by the starter engagement.
steve

 

S

sp53

Yoda

Offline

• Nov 15, 2020

• #13

You can also push the car in 4th gear to move the ring gear and free the starter also maybe, but something could break. I second what John said. In my view those shops are always training somebody

 

Sarastro

Obi Wan

Silver

Offline

• Nov 15, 2020

• #14

Yikes! Sparks at the firewall connection? I think you found the problem. You obviously have a bad connection there. Are you sure it's metal-to-metal? No paint in between?

This is why I have always run the battery ground connection directly to the engine block, and then run a strap from the engine block to the frame. I also run at least one cable from the frame to the body, so I'm sure there is at least one good frame-body connection.

 

OP

R

Redoakboo

Jedi Warrior

Offline

• Nov 15, 2020

• #15

I got a longer negative terminal and grounded it under the upper starter bolt. Bingo, started right up. Thanks for you guys help; it's been a long road. I still have to install the harnesses on the overdrive and figure out the steering column wires.

Dick

 

CJD

Yoda

Online

• Nov 15, 2020

• #16

2) If the battery grounds to the body and the frame grounds to the engine, you have to connect the body to the frame somehow. This is done through the 18 body to frame bolts. There is no strap connecting the body to the frame electrically...just the 18 body bolts. Normally just installing the bolts scratches enough paint to ensure a decent grounding connection...but at least one restoration on the forum was painted so well that the owner did not get a ground from the body to frame. He had to remove one of the bolts and remove paint from the frame and body...and then re-install the bolt.

The "thunk" you describe, along with the sparks tells me you have much higher than normal current draw. That normally points to a stalled starter, which is essentially a direct short. Ensure the starter and flywheel are not jammed together.

Are any of the 5 items the shop pointed out relate to this?

 

OP

R

Redoakboo

Jedi Warrior

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• Nov 15, 2020

• #17

After grounding on the starter bolt, it cranks right up?

Dick

 

S

sp53

Yoda

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• Nov 15, 2020

• #18

This picture is not the best, but it is the stock grounding cable

 

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OP

R

Redoakboo

Jedi Warrior

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• Nov 15, 2020

• #19

I have this ground strap in this exact place. Motor mount bolt to timing cover bolt.

 

S

sp53

Yoda

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• Nov 16, 2020

• #20

John suggestion about a poor ground because of paint sounds good and needs to be confirmed. Maybe your ground strap needs to have some paint removed on the ends. Perhaps there are 2 problems a weak connection with the starter somewhere in that circuit and the starter itself needs brushes or an armature or something. Was the starter rebuilt? Is the starter a stock one or a new high torque model? There are 2 high torque starter models for triumph 2,3,4. The only difference is the amount of teeth on the starter gear, and that is only one tooth difference. I am not exactly sure, but I think the early triumph used a 10 tooth and the later 11.
steve