turn key on then off and gauges go haywire

check the negative battery cable for corrosion and sprouts to other circuits, wire brush 'em clean, check the other end to assure the connection to frame and to engine are both clean and sound, then we will talk...

You can use your garden hose and blast away all the corrosion, won't hurt your battery a bit, and will clean that area of the engine compartment too-

the neg cable is not grounded to the engine they have it on the fender well but all that has been cleaned and all

Yay. just be sure all them volts and amps can get thru without it catchin' fire!

so where is the engine ground? An lollipop with a hole in it each end, bolt to powersteering mount and to ground lug, either on battery or to the post that the chassis ground is on.

2/0 battery wire is what must be used.

your starter motor will try to set it on fire...looking for a ground-