Hi,
I have a 2002 Buick Lesabre custom, I am trying to narrow down the problem of the turn signals not working. I checked the two 15amp fuses. They where ok but replaced them to be sure. I replaced the Flasher Hazard/Turn Signal Lamp module located behind the ODBII port. That didnt work, However when I used the directional lever I can feel the solenoid activate inside the module just one click. The Brake lights and headlights work fine as does the wipers and washer. My next step is to replace the Turn Signal Switch. But before I shell out $200 for the switch I thought I would ask here for advice. I read that sometimes aftermarket modules can be bad so I ordered a OEM ACDelco 25654870 and I will try that one first.

Thanks

Let us know if that fixes it if not it sounds like the multifunction switch. But is your 4way switch on the sterring column or on the dash. If its on the dash it could be the 4way switch.

This is from a 2001, should be the same as a 2002.......

Disconnect the harness into the module......with key in the on position, turn directional lever to left turn......do you have power at terminal C, orange wire? If no, check T/SIG fuse....if fuse ok, either bad multifunction switch or open wire....

If you have power, check for power at terminal H and ground at terminal A.....if ok, jumper terminal H to terminal D....if left directional lights are on, bad module.....

If lights do not come on, there is an opening in the wiring, possibly at the fuse block....

Ok Thanks, 2nd oem module was a no go. Time to start checking the wires at the module plug, Thanks for that information. I will let you know what I find
Thank you

Update... I have the new AC DELCO D6244D TURN SIGNAL MULTI FUNCTION SWITCH. I connected all but one plug on the new harness. The old harness has 2 wires that go all the way to the back up under the dash and no clip I can see. I found the new harness has two similar wires that have a connector at the end but is to short to go all the way to the back. I am thinking I should cut the new end and splice it to the wires going to the back? Not sure what they go to. The first picture shows the 2 wires with the connector on the new harness, the 2nd shows the 2 wires from the old harness. To me they look the same but I am color blind so I need help with it.

Ok I am guessing the wires go to the Twilight Sentinel Switch.

The New multifunction switch didnt solve the problem. Time to start checking for bad connections

I give up. Replaced the fuses, bulbs, Hazard/Turn Signal Lamp module, and the Turn Signal multi Function switch. It couldn't be the Body Control Module could it?

Did you check the wiring like I suggested in post #3?

You have done all that stuff. Have you checked the grounds?