Autosport Labs

Why earth mjlj and edis at the same point?

I know it will make sence for some reason just I cant see it at the minute, just wondering why i cant earth the edis on say the inner wing somewhere and the mjlj behind the dash somewhere?

Can someone fill this little void of knowledge for me please.

The reason you need to ground both to the same point is because it says so in the instructions

http://www.autosportlabs.net/MJLJ_V4_ve ... guidelines

lol

And because the pip and saw signals to each unit has the same reference point through the ground wire, which is then connected to the same common point.

Also if you had the ground at different points then one could be bad. For example if you had a bad one at the mjlj, it would feel like you having a problem with the mjlj going all over the place but the engine would still run going to limp home mode and then not. If both units had a bad earth then more than likely it wouldn't run

Also...

If you have a loop of wire it can pick up electromagnetic signals. If you have separate earths then stray signals can be picked up in the loop between chassis point A - MJ - EDIS - chassis point B - chassis - and back to chassis point A again. If you take all the earths back to one point then loops are reduced to almost nothing.

Same reason why you should only connect one end of the screening on signal cable at one end - if you earth both ends then the loop around the screening picks up interference, which gets induced into the signal cables inside.

Like i said thought they would be a good reason for it, i do car electrics but sometimes the theory behind what im trying to do is unknown to me as i'm told how to do sumit and not why i'm having to do it, which is better in the long run as this theory will apply to more than than just the installation of the mjlj.



cheers peeps