1966 convertible gauges don’t work

[Tim66convertible]

My speedometer works but nothing else does. I replaced the voltage regulator and have 5.5 volts coming out but still nothing. Got “new” gauges on eBay, still nothing. Ground appears to be good. Not sure what is going on... any ideas?

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[Grahamp]

Does the ammeter work? Have you grounded each instrument at the sender, the needle should flick fully to the right, if it doesn’t there is a break in the wire to the instrument, or the instrument is toast. You can remove each unit fairly easily, connect it to two D cells in series, 5 volts, and test the instrument on the bench. If they work, then you have a wiring problem between the dash and the sender units. Assume you have replaced the sending units?

 

[57tbird57]

i had the same problem with a 65. ammeter was the only one that worked. had to replace all 3 sending units and gauges worked fine