Bad Earth Hell - cutting out lights and stereo

[carolinecook]

Can anyone help to shed light on the cause of my odd collection of symptoms?

When driving and 'jolting' the van slightly by accelerating or decelerating there is an electrical fault -


The lights and stereo cut out for a second AND the water temp sensor red light and glow plug yellow light in the dash flash on. The relay for the fog lights also clicks.

So far I have -
Checked battery earth - connected to engine
Checked gearbox earth - connected to chassis
Cleaned up daisy spade earths behind fusebox (modern type)
Taken out Fog light relay
Used a Jump lead to extra earth engine to chassis and also gearbox to chassis
checked stereo connections - all ok
NEXT to check - the spade earths on the LHS of the engine bay. Look fine and tight but could be screw be rusty and not earthing?

The cut-out and flashing dash lights problem happens when the lights are on
With lights off I just get intermittent coil and water temp dash lights providing in-car disco.

The flashing dash problem started after I had the gearbox out last year.
The cutting out lights/ stereo started last month with nothing obvious having changed.

What on earth (no pun intended) is happening?
Could it be anything to do with the alternator?

ANY help or advice on what to check next would be very much appreciated.

Thanks

Caroline

[ninja.turtle007]

I had exactly the same issues, mine was the strap from gearbox to body.

[Oldiebut goodie]

Positive lead work hardened and fractured underneath the sheathing? Or corroded through. Not unheard of.

[Allanw]

The ignition switches are crap too - replace it. Buy two, they're stupidly cheap.

Mine used to turn right off around left hand corners, and starting off up a steep hill.

[carolinecook]

So, the problem in the end was the gearbox to chassis earth. We put a brand new strap from the Starter motor onto the body around the engine opening and all the flashing dash lights and cutting out headlight problems were resolved.

The existing gearbox to chassis strap must be corroded or not actually connected to metal properly. Ill take it off anyway as Aiden Talbot points out that it does the gearbox no good by setting up a corrosion cell.

Thanks for all your advice guys.

[California Dreamin]

If it isn't doing anything, then it ceases to induce galvanic corrosion so unless you are removing the box anyway? I wouldn't bother.

Just be aware of fatigue on your new cable.....constant movement etc can snap over time so the cable needs to be fine flexible multicore or braided for flexibility and positioned at a point of least movement.

Martin