Parking brake light stays on

Wow. Your response is right on point. Thank you so much. I bought the van with 225,000 miles on it around 2 months ago. shortly thereafter the five year old battery failed. Auto zone charged it and said it was on its last leg They looked up the specs for a replacement and it was gonna cost $135.00 so I drove with it for another 2-3 weeks until it finally died and could no longer be charged. I then bought a used reconditioned battery for $45 from a local salvage yard. I had my girlfriend go pick it up because I was working. That battery worked fine for about 3 weeks until one day it failed. I jump started it and it failed again the very next time I went to start it. So I jumpstarted it again and drove to the salvage yard because it came with a six month warranty. When I got there they load tested it and offered me a replacement battery in exchange. so I installed that and the van cranked up good and strong however later that same day I noticed the parking brake light and speedometer issues but never would have thought they would be related to a battery. Now I plan to drive on a 300 mile trip tomorrow but I will go back to the salvage yard and probably show them your response and see if they can set me up with a battery that meets the specs for the vehicle. I am sure they will if they have one and they have lots of them. I think they just didn't know? they are a longstanding reputable business. You say our vans are really about their power levels. Can you please tell me what are the specified voltage and amperage levels? Also what are CCA's? YHOur s