P1 Engine bay ground cable question?

[scot850]

I am doing some work on a V50 T5 AWD for a young student, and due to a charging issue one of the things I am doing is cleaning the engine bay grounds. I was surprised by the corrosion on the ones in particular on the strut towers. But even more surprisingly, when you remove the hold down bolt and cable, the ground point has paint on it?? So the grounding is being done by a bolt that is oxidizing heavily by contact with the threads into the body and the circular crimped end on the cable. That though is only grounding on one side where it contacts the underside of the bolt head?

Seems a very poor design? I will clean the paint off, clean the bolts and cable ends and re-install and coat with die-electric grease.

Neil.

[scot850]

Update. In Volvo's defense, once you remove the ground cables, and then run a wire brush in a drill over the painted area under the bottom of the grounds, they sit on weird little washers that have 4 raised 'buttons' which I guess are designed to push into the connector eye on the end of the cables and give a very small extra point of contact. That would work better if they were not painted over in the first place!

I cleaned them off, de-oxidized the bolts, ran a tap down the bolt holes and then sprayed the bolt and threaded holes with contact cleaner and wire brushed the connector eyes to clean of the oxidation and paint and then refitted them all and then covered them with a protective grease designed for that purpose.

So hopefully they will now have better contacts.

Neil.