Clean up the gounding connections.
On the bolts, use a wire wheel/ wire brush to return the threads (and underside of the head) to bright metal.
Also, clean to bright metal, both sides of the ring terminals that the bolt passes through.
The female threads in the frame weldnuts that the bolts are threaded into.
The area of the radiator support frame that is under the stack of ring terminals.
Location of RH side lighting group ground connection:
