ABS help with troubleshooting

I have a 1998.5 and have owned my truck for 13 years and only activated the RWAL twice and it didn't work both times. I now have a ABS light on and changed the sensor on the rear end with on joy. I have had it to all of the dealers within 100 miles of my house and it appears that their DRB111s can talk to it but are not functional enough to read the abs module or reset the tire size ( all if them looked really beat). My first question is there a way to determine if the module in the dash is bad or the hydraulic unit under the hood is bad. The second question is only because I am leaving on a 5000 mile trip in 8 days and I would like to kill the ABS light on the dash and still have the brake light in the dash functional along with the speedometer. My speedometer is still working and I have never seen it drop out so I don't think that I have a broke wire to the sensor. My third question is there a way to kill the power to the hydraulic unit under the hood to keep it from activating other then unplugging it from the harness. I am 70 years old and learned high performance driving before ABS and have no problem with it not working for this trip but don't like to leave things broken.

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