Question: volt gauge

[fgvanwhy]

I just changed the alt. on my 75 vette but the volt gauge don't move. What do I check to find the problem. Thank you

 

[TimAT]

Link to 75 wiring diagram:

Index of /johdotukset

Check the connector at the alternator. Not at all uncommon for the small brown wire to break at the terminal. It looks OK, but the wire is broken inside the insulation.