Transmission tunnel earth point(s)

[TV8]

as my topics over the last 12 months have all had a common theme (where has my 12 volts gone, hyper active speedo/Rev counter, speedo going backwards on light throttle, indicators staying on, speedo stopped working etc)the time has come for me to get it sorted properly.

I am pretty certain that these characteristics are linked to stuff under the dash - earthing points and alarm.

I have been planning to change the dash as well, so I am going to fit a new alarm and check-out all the wiring, assuming it all comes apart fairly easily...

The earth point on the transmission tunnel looks tricky to get to, so optimisitically, it is probably easier to fit a new earth lead than get a good clean-up on the current one.

Is there a list anywhere of what uses this earth point and is there a good point to cut-in a new earth feed?

Any other advice would be appreciated.

Thanks Graham

[spend]

Everything on the car uses it, its the single point of failure where the battery negative is connected.

[TV8]

Thanks Spend, is that the one on the nearside? If so and provided can get at it, I will check that before dismantling anything.

I thinking (hoping!)that there was one going into the dash area on the drivers side - more of a distribution type earth?

[TV8]

any more thoughts please people?

[TJC46]

TV8 said:

any more thoughts please people?

If i remember when i did my bodyoff the transmission earth point is similar to the earth point at the front under the rad i.e Its all individual earth cables coming from whatever, terminating via round electrical connectors which use one of the body bolts to connect to the chassis. Its a good idea to create a better or an additional earth for the battery to the chassis, but it wont help all the individual electrical connectors as mentioned earlier. I think your first job is to access the transmission earth points,undoe them, clean and check all the individual connectors and on reassembly use plenty of copper grease. You may have to make a small cut in the carpet to peel it back to expose the earth points. 2nd job to do would be the earth point at the front under the rad. Same again check and clean, and copper grease.
I attached a few extra earth straps at various points. Extra from engine to chassis, another one from the gearbox to chassis etc.
Now it would be beneficial to make sure the earth from the battery has a good contact with the chassis, and hopefully no more electrical gremlins, good luck Tom.

[TV8]

I managed to find the two earth points on the transmission tunnel and neither of them were loose. I lossened and moved them about a little and re-tightened them. Didnt make a lot of difference. Same with the earth under the rad - were they having a laugh when they located those three! The main earth in the drivers side wheel arch has been properly removed and cleaned. I think that just leaves the one on the engine - ran out of time.

Next job dash top off and check for loose bits unless anyone has some fresh ideas please?

[floyd12345]

I had some electrical problems after doing a body off i had cleaned all the earth connections so they all looked spot on.
it turned out to be the earth at the front under the rad there are a lot of individual wires using one connector bolting to the chassis. looked good but after peeling pack the insulation some of the wires had come away from the connector. i would never have have spot ed this just by cleaning it up.
I cut the old one off fitted a new one and all OK.

[ralphy12345]

On this subject...
I'm intending to move my battery into the boot and have a question:
is it OK to simply extend the positive cable from the existing location (in the passenger footwell) to the boot and then make a new negative cable to attach to connect the battery to a suitable chassis point back there?

R