1992 Pontiac Sunbird Broken Speedometer

Electrical problem
1992 Pontiac Sunbird 4 cyl Two Wheel Drive Automatic 19000? Miles

I was recently given a 92 Pontiac Sunbird for free. No severely debilitating problems, but there is an apparent, albeit slow, oil leak, and I have yet to get the radiator cap off so I can't check the fluid level. No other problems thus far until today. The ABS light has been on since I received the car It was raining, and in the low 50s outside (F). I was going about 25-30 mph, and braking for a stop sign when I heard/felt a slight knock in the rear (I suppose around the tires) while breaking, when the ABS light cut off and the speedometer just shut down and went to 0. It didn't go back up the whole rest of the drive but no other problems arose. I had the lights, radio, and wipers on all at once, so I'm not sure if that had anything to do with it. I'm pretty inexperienced with cars and car repairs so I'm not sure if a wire was broken, water got where it shouldn't, etc. Any ideas would really help because I'd like to not drive without a speedometer, and I'd also rather avoid paying someone to fix it for me. Thanks