Electrical Issues

Things on my series 3 appear to be getting worse with regards to the electrics. The stereo cuts out all the time, the indications come on but do not flash, and the headlights get brighter when the handbrake is pulled on. Also, considering I have a great big new battery in there, the starter motor seems a bit sluggish.

I suspected a bad earth somewhere, but having checked it all it all seems as it was when I first did the wiring. Any ideas?

you need a fairly heavy earth straps between body,chassis and engine

Ive got some braided steels ones atm, i dont know if they've got worse over time? there is an isolator on the negative terminal as well, and another earth running directly from the starter motor

but is body, chassis,engine all earthed and is isolater poor contacts etc or big enough

id check that the bonnet stay prop isnt shorting on the live terminal on the battery when its closed ( seen it happen a few times meself now )

check for good connections on cable lugs,battery terminals,corrosion on fuse holders and ignition switch

What about using a jump lead from battery to chassis?
Also try another temp. earth from the chassis to negative of the head lights. I suspect the headlights and inidcators would share an earth which could be dodgy.

Indicators could also be the flasher unit. It won't flash unless it has enough load. I.e. if you stuck in a low watt light it won't flash.
Do you have a warning light for your handbrake on the dash? If so I tink they are wired with power to the light and when the brake is applied it makes a contact.

I just rewired my car as it had to much tape holding wires together. Too many cut wires and too many redundant parts. Everything now works and I understand the system.