88 Honda Civic Alternator Question

Just installed a new alternator in a clients Honda due to faulty diodes in the original one.

Now, when you start the car there's about a 2min delay before the alternator start to charge.

You can actually get it to charge imeadiately if you put an electrical load put on the circuit (ie. Headlights, rear window defroster, etc.) Basically if you flick the headlights on for a few seconds and shut them off right away the alternator begins charging right away.

Of course when you begin to troubleshoot the problem, the alternator has already kicked in and everything checks out perfectly fine.

I know that there's really nothing to worry about as it "IS" charging, just seems odd that it would have that delay.

Any ideas what might cause this?

Any help would be greatly appreciated!

Thanks