GM Repair Problems? Ask GM Repair Expert Now.
swapping the relays makes no difference ?
if not when the low beams are on when they should be lit up if you pull out the LOW beam relay do 2 out of the 4 terminals in the box show 12 volts ?
out of the last 3 terminals will one terminal show a ground when the low beams are set to on then the ground go away when the low beams are shut off ?
ok if one terminal does NOT show a ground when you torn the LOW beams on then the issue will be the BCM bad or the pink/white wire from the BCM to the under hood fuse box being bad or a bad terminal or connection from that wire under the fuse box or an inter fuse box failure
usually its best to get under the fuse box and see if you get the ground on and off when selecting LOW beam if you do not then that one wire is bad or the BCM is bad
the low beam when selected should turn on a ground then off with that ground when high beam is selected
with the relay back in do you feel that relay click on and off with your fingers when low beams are turned on and off ?
this is a basic headlight set up as seen here
at this point get under the under hood fuse box and be sure the wiring all looks good
if it does then find this connector C2 as seen in this picture and find terminal # *****! it will be a pink/white wire
that is the signal wire to the box from the BCM to turn on and off the low beam relay see if that wire will show a ground when lows are turned on and no ground when turned off
if it does NOT do that the wire from the box to the BCM< is bad or the BCM is bad
if that wire DOES do that then either the terminal or connection at the under side of the under hood fuse box is bad or the fuse box internally has failed and would need to be replaced
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here as seen in this picture
let me know
usually if they wont lift off all in one piece to flip it over then loosen the 3 bolts
the BCM will not work the BCM has to be programmed to the vans VIN number with the correct programming for it to work it is NOT a plug and play module
i would leave it connected if you can then once up it needs to be plugged in to do that test on that wire we talked about
just getting it up enough to find and test that wire and check the terminal