Chassis earth/negative

In the past when using my compressor after some ff road action, I have never had an issue connecting my compressor to the battery positive and the chassis as shown in the manual for negative. On a recent trip no matter where I tried I could not connect a negative anywhere on the chassis and only n he battery worked.
A is this risky having the compressor direct on the battery and
B where as my chassis earth/negative gone?

Cheers

I thought (but I'd need to check), there was a specific bolt in the engine bay for this purpose... I'll pop the bonnet and have a look again.

You're right RacingSnake. It's recommended for jump starting. In the handbook (page 206) it shows a bolt on the right hand side just behind the windscreen washer filler cap. The bolt is a part of an engine mounting.

(03-07-2013 01:30pm)recordman Wrote:  You're right RacingSnake. It's recommended for jump starting. In the handbook (page 206) it shows a bolt on the right hand side just behind the windscreen washer filler cap. The bolt is a part of an engine mounting.

Thanks guys
Aware of this bolt. Whats odd it used to work but doesn't now. I suppose it could be the compressor somehow but it does work fine battery terminals.
What I worry is can I potentially do damage somewhere? Obviously the current flow is different to charging.

Seems odd, The compressors obviously working if when connected to the Battery it runs, You'd need to get a meter to see if the negative of the battery is still connected to the earth point on the engine mount, if not something may be damaged already and hence it no longer working, although you'd expect other electrical problems if the engine is no longer earthed!

Could be the battery monitoring circuits/ device doesn't like you loading the battery that way by drawing charge when the earth is for jump starting. Can you not change the crocodile clips on the compressor to a cigarette lighter type plug that will work in any of the power points? That's how all three of the compressors I have connect and they have interchangeable cables ( one is the one tat came with the tyre gunk kit to replace the spare and the other two are Halfrauds compressors made in China that have a load of different connectios all interchangeable