2000 olds bravada
OEM radio would not hold memory or time. Checked fuses(RDO) was corroded,cleaned contacts and replaced fuse, Still no memory. Replaced head unit with Pioneer nav unit, worked good for about 10 mins then unit shuts off, checked 12v constant good, checked 12 switched no power, 10 mins later power came back for about 10 mins then went back out

 

This could be a problem with the RAP (retained accessory power) relay or possibly the ignition switch itself. If you have no power at the RDO IGN fuse, then work your way back to the RAP relay.

The BCM (body control module) grounds the RAP relay to power those items which are on the RAP circuit (mainly the radio) via the RAP fuse (50A) until the BCM times out, shutting down the circuit. When the ignition switch is in the RUN or ACC position, power is directly fed through the normally closed contacts in the relay to the circuit.

To narrow down the cause, put the ignition switch in the RUN position and wait for the RDO IGN circuit to lose power. Once it loses power, check for operation of the wipers. If the wipers don't work, then the ignition switch contacts have fried. If the wipers work, then the contacts in the ignition switch are good and the most likely cause of your problems is a failing RAP relay.

 

where is the rap relay located