turn signals non-existent when idling

Loving my new 79 650. Now it's time to begin sorting out problems. The starter doesn't work but the kicker works great. So here's my first dilemma....the signals don't work at all when at idle. As soon as I bring up the RPMs they are fine. Sign of a weak battery? Other suggestions? Also, I'm trying to figure out specifically what model of 79 kz I have...spoked wheels, drum in the rear and single disk up front. I know that my seat is non-original and off of a 78. Thanks in advance for your words of wisdom.

Scott in Rhode Island

Welcome Scott! Yes it sounds like your battery and or charging system is not up to snuff. Do you have a factory service manual? It will help you test your electrical system. Your bike looks to be a B3 model. Look on the steering stem for a white sticker. The full VIN will be there.