Strange noise

Hi,
I just purchased a 1995 SL1. It has 95,000 on the car. It was a tow vehicle for an older man.
It has an automatic transmission. It runs great but makes this funny noise. When you put the car in drive after having it completely shut off and after starting to accelerate to about 5 mph it makes a funny click clack noise followed by a beep. It does not sound mechanical but like a relay or something. It only does it once. As long as you don’t turn the car off completely it does not do it again no matter if you put it back in park. If you turn the motor off and turn the key to ACC it does not do it. No other sounds at all. Transmission shifts fine.
Has anybody else ever had this problem or know what it might be?

Thanks
Fionnbharre

duplicate post, different title

It may be any electronic problem in your car.You can take advice from mechanic to fix it.

It might have something to do with the HVAC system. Sometimes those vent doors will make a sound like that, esp if there’s some kind of mechanic problem with the doors or the motors that control them, like if they are sticking. Does the sound seem to come from under the dashboard?