Abs Break light and Parking break light
That ended up being a busted brake line, which in turn led to a low fluid level in the brake resevior. In other post on this forum, it could be be your sensor at the rear diff. for the ABS brakes. Search around for it.
The ABS light and parking brake are on 
I think the other post mentioned how to tell, but I also think they mentioned it was a $25 part, so it's not a big hit just to replace it.

I think the other post mentioned how to tell, but I also think they mentioned it was a $25 part, so it's not a big hit just to replace it.
what do you drive? I had the same problem with a 2004 Ram 1500. Found out it was water in the connector at the Anti-Lock brake controller. Common with newer model Rams. Dry it out, pack it with dialectic grease. Should be good. I also saw that my speedometer was fluctuating.
On my '97 I was screwing around in the snow. Dumped the clutch and whipped the rear around in a quick 180, then slammed the brakes and slid sideways to a stop. As soon as the brakes locked and I started sliding sideways, the lights came on and stayed on. about a month later I disconnected the battery for a couple minutes and it cleared the code and the lights work properly again. I'm pretty sure mine was only caused by me doing something the truck didn't like.



