Electric Problems

[Guest graemeacross]

This one is quite interesting.

I have just fitted new Smiths guages to my S7 along with a new radio that I also wired in. While stationary everyting operates fine with the engine on or off but when I move the radio cuts out and the dash lights flicker :angry:. This seems to occur when the clutch is in transition and the is car is moving. When the speed picks up and the revs are fairly constant everything is again happy until I push the clutch peddle to change gear and once again the radio goes. :boohoo:

With the engine on and the car in neutral I can change gear and play with the clutch to my hearts content with no problems.

I have checked the alternator and grounds which seem to be good.

Any ideas?

[Guest Bob Rowell]

I have seen a similar problem a couple of times, especially on Fiesta's and Sierra's. It usually turned out to be an earth problem where the earth lead from the battery is connected to a bolt fixed into the corner of the battery tray. Taking the bolt out and cleaning everything with a wire brush before re-assembling usually did the trick.

ps. Does anyone remember the early days of the Mini when the earth strap failed and the choke cable became the only earth route. Cables used to glow red hot!

[Guest Tim Norman]

I had a throttle cable act as an earth once. It melted the outer cable and I to operate the cable by hand to get home. I now have at least three earth straps on the car!!!!!!

[Guest graemeacross]

Thanks guys. I think I have solved it. The negative terminal of the battery is connected to the engine but the majority of the services come from chasis ground. Unfortunately chasis and engine ground were different and I think when the clutch engaged the grounds met and through my radio out.

A bonding lead between the engine and chasis seem to have sorted the problem but I think I'll take your advice Tim and get a couple more.

Cheers

Graeme