Caterham 7 repeated total electrical failure, after 2 miles

[Pan Pan Pan]

Pan Pan Pan said:

Tazio77 said:

Good to see you may have fixed it, but just one thing, you state that you have checked all of the earth connections, does this include the earths that use the wiper motor bracket?, easily forgotten as you really need to remove the scuttle to check. The reason I ask is that's where my problem was, and like yours nothing worked when it failed.

Hi there. The main connections to the battery on my particular chassis are as follows. The battery negative cable is fixed to a terminal secured to one of the engine mounting bracket bolts, The battery positive cable runs directly to the starter motor. A further heavy cable runs from one of the bolts which secure the clutch bell housing to the engine block to the bolt that secures the brake light switch to the chassis. As posted I re made these several times, after which the car would start instantly and run normally whilst on the drive, but would lose all its electrical power, after a circa 1 -2 mile run on the road.
As the cables were all of sufficient length, I cut the existing terminals off them, and re made them with new terminals at each end of each cable. the car now starts instantly as it always did, but now keeps on running for longer than the 1-2 miles it was completely failing at before. It may have to run for a good few miles before I can completely trust it, but (so far it appears to be running properly again. All comments I have received on this have been much appreciated so thank you all once again..

Thank you for your advice regarding the earth to the fuse and relay panel under the dash. As the car is working OK now, I will go with it as it is for the time being, but If I do experience another earth failure that will be the first one I take apart, on the basis that it is the only one left, that I have not taken apart and remade. Best Regards to you and all who offered advice on this.

[Pan Pan Pan]

Just an a update on all of the above. I took the seven out for a 100 mile round trip, in convoy with another seven (just in case! )and it worked fine, and did not miss a beat, so it looks as if the problem has been sorted out. I am getting to the point where I feel it cam be trusted again, I just wanted to let those kind enough to send advice know that the seven is working again, and that it was most definitely a main earth problem, in the end. Thanks to all.

[downsman]

It's great when we get a final answer, and will be useful to those searching in the future. Have fun

[SLR400]

I had a similar problem with my first 7 a 1.6 VX. Turned out everything was shorting when I was changing gear and from memory it was something to do with the reverse light switch on the transmission tunnel causing a short when I was changing gear. May be worth checking.