Proper Grounding
Proper electrical grounding is essential for reliable operation of the car’s electronics. Here’s how my TR6’s battery was grounded:
In case you can’t tell, it’s a length of red wire (typically used for positive), partially wrapped in black electrical tape, and terminated at a bolt on the transmission:
As with many of the tasks performed on this TR6, step 1 was “undo”. As an aside - if you’re wondering what that blurry bit on my accelerator shaft is, don’t worry, I’ll come back to that later (remember what step 1 was?).
A proper ground for the TR6 involves the use of a braided cable that connects to the battery, engine, and body. You can see the body connection bolt (with nothing on it) in the previous photo. I took the cable off the battery and the transmission, then replaced the transmission bolt since the new cable wouldn’t be connecting there.
The new cable would connect to a bolt on the rear engine hoist point, the previously mentioned body bolt, and the negative battery terminal. Here’s the engine hoist point as I found it. Can you see what was wrong?
Yep, looks like someone forgot a bolt. At least it was still in the block. I did not have one of the braided cables (nor did I wish to buy one), but I did have access to lots of big wire, so I grabbed a couple feet of 4 gauge stranded copper and made one:
I reused the end from the old cable, and fabricated a new clamp for the mid section that attached the bare portion to the body. I ended up soldering this clamp to the bare section to ensure a perfect connection at all times. I then sanded the area around the body connection down to bare metal, and cleaned the hoist point connection as well, then hooked it all up.
Remember that bit I mentioned earlier? Well it appears as though someone replaced the worn out accelerator shaft bushing with a section of rubber line and a hose clamp. Ingenious! This is also a good shot of the new end and middle connectors.
Here’s the new battery end:
I included that shot to point out the shutoff knob. I think I got this for a few bucks off ebay, and I highly recommend it. Opening the switch will prevent the battery from dying due to any stray currents while the car is off. As a bonus, any time you do electrical work you should disconnect the battery, and this makes it trivial.
In addition to this main grounding point, the TR6 wiring harness has a few other grounds. There’s one in the rear (no photo, sorry), and this one in the front by the grill (which was fine on my car):
There is also one near the battery on the passenger side of the car in the form of a small tab welded to the body. On my car this tab was broken off, but you could still see the base. I tried to make it easier to spot in this photo (the nail points to it, and I highlighted it):
The plug that is supposed to go here still existed, but was rusty, and I think it had the rusted remains of the tab stuck in it:
I made a new tab out of a piece of a picture hanger, and after cleaning the area down to bare metal, tacked it on with the welder. I also removed the old plug and soldered a fresh one onto the wires. I prefer to solder and crimp because it gives a much more solid connection and doesn’t allow for corrosion to get between the crimps and the wires. Here’s the new tab with the new plug connected. That little piece casting a shadow is the remains of the old tab:
Once I am further along (or if I notice odd things happeneing electrically), I may need to add additional grounding wires, especially from the lights to the body, but I’ll cross that bridge when I come to it.