Gauges

I put new VDO gauges in my street rod and ever since the installation when I turn the headlight on the Temp Gauge starts to climb and the Oil Pressure Gauge starts to drop. As soon as I turn the headlights off the gauges return to what I think is normal. I am stumped. Is this a bad ground for the gauges or a faulty alternator or what?

You need to clarify some information. Are the two guages indicated above the new VDO's? 1. How have you supplied +12 VDC to power the guages? - switched, unswitched, ignition, battery? 2. Where are the guages grounded? And how were they grounded? 3. How is the sending unit installed? Mechanical / electrical units? - Did you simply splice into the OEM sender(s) - Did you install your own? And are they properly seated with the appropiate fittings? Regards EVIL Teken . . .

i would move the gauge grnd to a new spot . maybe to a good clean spot on the frame or the engine block . i did a simulated set up like that and i put my gauge grounds on a firewall bolt from inside .