I have a 1985 Volvo 245 (wagon) and when I try to turn the key, the ground wire that goes from the battery to the engine block jumps about 2cm, and the car does not start. Does anybody know what the issue could be, and how to fix it?

 

Jumps how? Where? Is it loose? Does engine turn over? Is the battery good?

 

the ground wire should go from the battery negative terminal to the CHASSIS, then from the chassis to the block, not directly from the battery to the block, unless someone added that.

 

The wire is not loose, and the battery we are still unsure if it is okay. And there is also a chassis to engine ground, and the engine to battery ground

 

again, the ground cable should go battery - -> chassis -> engine. not directly from the battery to the engine.

is the engine moving excessively when you crank it? your motor mounts may well be shot.

 

The motor mounts are definitely shot, but should I just move this ground wire to the chassis? Because as is it is battery-->engine-->chassis from what I see

 

sounds like someone replaced the ground cable at some point, then. where on the engine is it anchored ?

 

From the front of the car, it is on the lower part of the block, on the right side near the front (I'm not with the car at the moment, or else I would be able to give a better description)