Classic/Antique Car Repair: 1957CHEVY CAR, back ups, stock water

Question
I HAVE A 1957 CHEVY 4 DOOR HARDTOP STOCK OUTSIDE & INSIDE BUT FROM FRONT TO REAR ALL NEW HIGH PERFORMANCE
QUES: How can I check the stock Water Temp & Fuel Level guages? I have new VDO back-ups but would really like the stock guages to work.
Thank You
Larry

Answer
If you haven't modified anything in the dash, the gauges should still work.  The way to check them is to find the wires that go out to the senders, and temporarily ground them to the body while you watch the gauges.  The needles should immediately begin moving upscale as soon as you turn on the key.  Don't leave them grounded for more than a second or two - but if the gauges move upscale, the dash units are probably OK.  Just hook up the original senders to the wires and the gauges should work properly.

If the gauges do not move upscale when you ground the sender leads and the key is on, you'll have to get a wiring diagram and troubleshoot the wires on the gauge units.  

Also, check the instrument regulator which provides the pulsing signal to operate the gauges - it must be working and the wires connected to it.  One wire goes to the ignition terminal on the ignition switch, one goes to ground, and the 3rd wire goes to each gauge's hot terminal (not the sender terminal).   If you put a test probe on the instrument regulator output (the wire that goes to the gauges), you should see a pulsating voltage there - the meter or test light should show a pulse about once per second (this isn't critical).  If you see that, the regulator is OK.  If it isn't, get a new one - they're cheap and NAPA still stocks them.

Dick