Truck has 195,000 on it. after it has been running for a couple of min the abs light and the parking brake light both come on, brake fluid is full, has new front hubs with abs sensor in them (last year), and just put on new front rotors and pads. Is there a sensor in the rear brakes that is setting off both of them?

Replace parking brake sensor.

I believe the fluid/brake light is only intended to indicate the parking brake is on or the master cylinder reservoir is low . ?????

Wrong !!!!!! problem's with ABS can also turn on that light as well ! Take it a have codes checked .

It could be a problem with either system. The ABS uses the standard hydraulic brake system in addition to the ABS components.
You would need to get the ABS system checked out if the parking brake is off and the master cylinder is full of fluid.

Check to make sure that you have ample brake fluid in the brake fluid resovoir. If it is full and you still have the light on, you may have to get it scanned for computer codes, or ABS codes.

The brake light will illuminate when the hand brake is on and when the brake fluid is low. Have you checked to make sure the brake fluid is full in the master cylinder reservoir?

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

CHECK ALTERNATOR OUTPUT IT SHOULD BE 13.5 TO 14.5 VOLTS WITH ENGINE RUNNING.IF VOLTAGE LOWER 12 VOLTS THAT WILL CAUSE BRAKE AND ANTI LOCK BRAKE LIGHTS TO COME ON BECAUSE THAT NOT ENOUGH POWER FOR ABS BRAKES OPERATION.IF ALTERNATOR GOOD.BRAKE AND ABS LIGHTS ON ALSO MEANS LOW BRAKE FLUID LEVEL CHECK BRAKE FLUID LEVEL.ALSO. YOU HAVING BRAKE FAILURE.YOU NEED TO HAVE GARAGE OR DEALERSHIP CHECK BRAKES SYSTEM.BEFORE BRAKES COMPLETELY FAIL.

Hello treedy22.
Your car has a switch inside the brake master cylinder reservoir that will activate when the fluid level gets low. This will turn on your red brake light and deactivate the ABS system. That is why both lights are lit.
Check the fluid level, refill with DOT3 fluid ONLY. It may take a couple of minutes for the light to turn out as sometimes the switch sticks in the bore inside the reservoir..
Then you need to find out why the level is low. Check your braking system for leaks or excessively worn brake parts.
Hope your repair goes well.

most ABS problems are broken wires at the hubs

is it the abs light or the brake light there could be a couple different things wrong with it. if it's the abs light your abs system is acting up and it will need to be checked out. if it's the brake light then your brake fluid level sensor could be bad, or your parking brake switch could be going out, and there's other things that could be wrong with it.

maybe the trouble is in switch located on park brake lever