2 Voltage regulators????

[my new 72]

Looking around under the hood today trying to find out why the he!! the front turn signals come on when I put it in reverse instead of the back-up lights, when I noticed that the external regulator was still hooked up. The PO was running an internally regulated alt. when I bought it, so when I put my one wire I didn't think to look to see if the old regulator was still hooked up. After all, why would it have been. Would both regulators working against each other do any damage to the alt.? I fixed the problem, but I just want to make sure it didn't do any damage.