1998 GMC Jimmy. 4WD, 4DR. no vehicle history.

Scan tool shows B1477 & B1480 (battery run down protection). The b1480 was there when I bought the vehicle along with a parasitic drain (.8 amp) on the battery and a dead battery. Traced the drain to the stock radio which when removed eliminated the drain. Replaced the battery.

I cannot find any diagnostic trees for the two codes listed above. Can someone help?

In addition I've noticed that the power mirrors do not work, power locks seem slow to respond, and power lock switches Do not activate all doors. Power windows seem fine.

Ps. Working on an O2 sensor problem in another thread. Expected it is totally unrelated.

 

Here are the DTC listings for the two codes you are getting:
B1477 - Retained Accessory Power Circuit Low
B1480 - Battery Rundown Protection Circuit Malfunction
The wiring information should be the same for a '98, but is for a '00.

I didn't have time to look through the two codes to see if there are points of commonality, but might later today. Have a look and let us know if anything jumps out at you. If you run through the testing, let us know the results.

I believe that the mirrors & locks are on a separate circuit than the RAP (retained accessory power) circuit.

 

Finally got back in the garage. Vehicle has a new battery now, both circuits do look for battery voltage at the bcm. Using the diagnostic trees I found the rap and inadvertent power relay turned on and off with scan tool. The diagnostics for the 1998 were slightly different than the ones in the above referenced links. The code both showed up as history and pending so I have cleared codes and will monitor for repeats.

I sill have the problems with the mirror and locks. The power lock controls do not lock or unlock the drivers door lock, all other locks work fine from both switches. Scan tool locks and unlocks ALL doors.

The power mirrors did not work at all, after disassembling and cleaning the switch they work in three directions. Up, down and left. They do not operate to the right.


Thanks

 

Some additional information. I realized that the dome light is not turning off once the car is started and the door closed and that got me to thinking. All of these systems have the door switches and the BCM in common.

I've pulled the 4 door switches and they ohm out as okay. The lift glass switch in the rear lift gate ohms out okay as well. I think there must be a switch for the liftgate (not tailgate) but cannot find it. I've pulled the connector on the BCM and verified that it is getting a liftgate ajar signal regardless of the state of the lifgate. Can someone tell me where this switch is located?

This thread helped find the switch https://blazerforum.com/forum/gmt-36...-always-14761/ and here is a picture of mine after removing the liftgate trim.

The connector on the left is for the liftgate ajar jamb switch. It turns out the connector was corroded. Cleaned it up and the light is turning off properly.

Door locks are working properly now too. I think the lockout prevention system was unlocking the drivers door. Or moving the wires around to get to the power mirror switch fixed a poor connection.