TR3A Bulkhead Earthing Point

[angelfj]

This week I finished the wiring of the control box, fuse block and solenoid. With this branch of circuits is a black (earth) wire with a ring terminal. My guess is that it goes under the head of the control box attachment screw shown in the photo, but I'm not sure. If not could someone please tell me where this should go? A photo would be great.

 

Also shown in this photo is the signal flasher relay which is fitted with a hex head bolt. Should there be a washer/s under the head of the bolt?

 

A general question regarding wiring these cars. I noticed that there is no earthing wire in the branch of the loom that serves the fuel tank sending unit and rear lights. It seems a good idea to add one. Is this a common practice?

 

[Trevor S]

Hi Frank, I've got a spring washer & plain washer between the bulkhead (and the pedal box) and flasher unit on my 2. However as stated, mine is located to the recessed pedal box, being rhd, so the box needs retaining as well as the flasher unit. I assume your car is a later 3a as it appears not to have the cut out and plate on the side opposite to the driver.

The earth wire to which you refer is attached on my car under the head of one of the solenoid retaining screws. I think from memory it wasn't long enough to reach the control box.

Like you I thougt an extra earth to the rear lights would be a good idea and I'm in the process of fitting one with a ring end so that it can be screwed on to something appropriate.

[angelfj]

Hi Frank, I've got a spring washer & plain washer between the bulkhead (and the pedal box) and flasher unit on my 2. However as stated, mine is located to the recessed pedal box, being rhd, so the box needs retaining as well as the flasher unit. I assume your car is a later 3a as it appears not to have the cut out and plate on the side opposite to the driver.

The earth wire to which you refer is attached on my car under the head of one of the solenoid retaining screws. I think from memory it wasn't long enough to reach the control box.

Like you I thougt an extra earth to the rear lights would be a good idea and I'm in the process of fitting one with a ring end so that it can be screwed on to something appropriate.

 

 

 

"so that it can be screwed on to something appropriate."

 

Hello Trevor. Yes. We intend to use a ring terminal on one of the fuel tank mounting bolts.

 

Cheers,

 

Frank

[Menno van Rij]

Frank,

 

A little off topic perhaps, but this is a good moment to ask, I think.

When I put my TR back on the road in '06 (prior to the restoration - just for insurance and legislation purposes), I found a fuse under the center gauge panel. The fuse was horizontally mounted on the plinth of the dashpanel. I think this fuse was intended for the rear lights. My TR is a 1959 ex-USA car. Does your TR have that fuse?

 

Menno

 

 

Edited May 27, 2010 by Menno van Rij

[angelfj]

Frank,

 

A little off topic perhaps, but this is a good moment to ask, I think.

When I put my TR back on the road in '06 (prior to the restoration - just for insurance and legislation purposes), I found a fuse under the center gauge panel. The fuse was horizontally mounted on the plinth of the dashpanel. I think this fuse was intended for the rear lights. My TR is a 1959 ex-USA car. Does your TR have that fuse?

 

Menno

 

 

 

 

Hello Menno. Yes, I have that fuse and you are correct that it is intended for the rear lights. I intend to add another fuse for the overdrive solenoid. The solenoid has a dual winding, a pull-in coil and a holding coil. Initially when you turn the dash O/D switch to on, the pull-in and holding coil are both energized, causing a large amount of current to flow. This causes the plunger of the solenoid to activate the hydraulic valve and overdrive is achieved. The motion of the plunger also causes an internal contact to open and de-energize the pull-in coil leaving only the holding coil energized. This is sufficient to maintain the opperating valve position. If the pull-in coil contact does not open due to some problem, the high current flowing will eventually destroy the solenoid winding. These are not cheap to replace, perhaps $100 or more. So, this is why I will be adding the fuse to this circuit.

 

Cheers,

 

Frank

[angelfj]

Actually I found a very old digital photo that I took in 2000 with a Sony Mavica. Less than 1 megapixel, but if you squint you can see the wire and terminal. The old grey lady was looking very poorly back then with her rattle can black paint finished engine compartment. Another much better photo (red 3A) follows.

 

 

[kiwi-jim]

Frank

looking at the original photo of your rewiring you showed, it got me thinking about what are the correct fuse sizes to install and in which side of the fuse box. You are showing in the photo a 35amp and a 50 amp fuse, and the 50 amp is on a different side of the box from another photo I have seen.

What are the correct sizes and which side do they go on?? Because I have to get some for my rebuild before I can fire it up??

Cheers jim

[stuart]

Frank

looking at the original photo of your rewiring you showed, it got me thinking about what are the correct fuse sizes to install and in which side of the fuse box. You are showing in the photo a 35amp and a 50 amp fuse, and the 50 amp is on a different side of the box from another photo I have seen.

What are the correct sizes and which side do they go on?? Because I have to get some for my rebuild before I can fire it up??

Cheers jim

 

They are usually both 50 amp but something like 35A blow.

Stuart.

Edited May 28, 2010 by stuart

[vivdownunder]

I've always put a 50amp fuse in the side with the heavy brown wires, which is the horn circuit, and a 35 amp fuse in the other (white to green wire) side, as I thought that's how they were originally.

 

Viv.