I have a 2001 2 door Blazer and I am having a problem with the interior lights. They come on with the keyless entry or by pushing in the dome override button on the dash, but not when you open the door. Also the radio does not stay on after the car is shut off like it is supposed to (not sure if this is related or not). I have checked all the fuses under the hood and also in the side of the instrument panel. I also replaced the door jamb switch. Any suggestions on what to try next?

Thanks - Brett

 

Possibly wire chafing, severed wires on the lines between the door jamb sensor and the Body Contol Module, poor connections on the switch or a defective BCM. I'll take a look at the manual and get back to you.

 

Do the lights turn on when you open the passanger door?

On later review of the play:

Did you check the fuse labeled 'RAP'? It is in the engine compartment and is one of the big fuses

 

Yup - I checked the RAP fuse and it is good.
The lights stay off when the passenger side door is opened. Same with the rear hatch.

 

Possibly a loose connector on the BCM.

The wires that control both the 'Retained Accessory Power' and 'Inadvertant Power Relay' are right next to each other on the plugs harness. These are lines A7 (Black) and A8 (Dark Blue) on connector C1 (Brown) going into the BCM. Shorting either to ground will verify opperation of the associated relays, with RAP opperating the stereo/power windows with the vehicle Off and IPR forcing the lamps to come on, that is assuming the Courtesy lamp relay is good which can be tested by shorting A3 (Gray/Black) on connector C2 (Light Blue) to ground.

If that is the case the BCM most likely has cold solder joints on that connector, solve by either attempting to reheat the connections or getting a new BCM. This condition may be verified by flexing the connector one way or the other and observing changes.

If the relays do not click as you are shorting the lines, you may have either loose or defective relays. No one is quite sure where the body relay block is, some people say behind the glove box, others some where around the interior fuse panel, burried in the dash board.

The Body Control Module is located under the ash tray in the dash board, behind the center hush panel.

 

I grounded out the lines and could hear the relays clicking. Found the body relay block by following the clicking sound- it is tucked way up in the dash close to the interior fuse panel. I pulled out the BCM and will see if I can get an other one. Thanks a bunch for all your help.

 

Did the circuits you were clicking turn off and on with the relays? Or did it just make a clicking noise? If it made a clicking noise and nothing happend the relays could have bad contacts.

 

Didn't think about that. I do know that the radio came on when I grounded out the wire, not sure on the interior lights. I'll double check before I shell out the cash for a BCM. Thanks again.

 

'IPR' can be verified functioning as it runs the light in the glove box, Sunshade mirrors and the underhood lamp, assuming they are open as they have local switches as well.

'IPR' also feeds power to the coil of the courtesy lamp relay, 'IPR' will have to be engaged to make 'CLR' work. So you will have to short A8-C1 to ground and then Short A3-C2 to ground at the same time. If that is successful the LH and RH console lights will come on as well as the cargo area lamp

 

I do know the glove box and underhood lamps are working. To check the 'CLR' you saying to ground all the pins from A3 to C2 right, or just pins A3 and C2? - Just checking - dont want to short something out.