How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Gary Your Own Question
Gary
Gary, GMC Technician
Category: GM
Satisfied Customers: 15914
Experience:  15 years gm master tech/15 years ASE master tech
19513769
Type Your GM Question Here...
Gary is online now
A new question is answered every 9 seconds

I have a 2003 savana van 1500 passenger awd. no low beam

Customer Question

Customer: ***** *****, I have a 2003 savana van 1500 passenger awd. no low beam headlights. High beams and drl and parking lights work. I have replaced the dimmer switch, head light switch. all fuses and relays are good. I ran a fused jumper from the battery to the contact terminal fter removing the relay and headlamps work. I also put juper from 12v supply to relay and fed 12v to terminal and both headlights work. ould it be a bad fuse or BCM?
JA: Thanks. Can you give me any more details about your issue?
Customer: High beams work but no low beam unless I jump out relay.
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $32) to post your type of question to GM Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: how long?
JA: OK. Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: GM
Expert:  Gary replied 1 year ago.

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 ?

Customer: replied 1 year ago.
swapped relays no differance, 2 terminals on left side of relay plug have 12 volts. there are 5 terminals on relay
Expert:  Gary replied 1 year ago.

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 ?

Customer: replied 1 year ago.
I will check now, 1 terminal has continuity to the 10 amp fuses for the low beam headlights
Expert:  Gary replied 1 year ago.

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

Customer: replied 1 year ago.
When I check the terminal I get continuity to ground with the lights off or when the low beams are on the ground goes away when the high beams are turned on
Expert:  Gary replied 1 year ago.

the low beam when selected should turn on a ground then off with that ground when high beam is selected

Customer: replied 1 year ago.
that is correct
Expert:  Gary replied 1 year ago.

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 ?

Customer: replied 1 year ago.
I will check now
Expert:  Gary replied 1 year ago.

ok

this is a basic headlight set up as seen here

Customer: replied 1 year ago.
no klicking when low beams are turned on, other solonoid klicks when high beams are turned on
Expert:  Gary replied 1 year ago.

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

if you have any questions please ask as i do not get credit for my work until you rate us here at Justanswer

Customer: replied 1 year ago.
where on the van is the BCM located?
Expert:  Gary replied 1 year ago.

here as seen in this picture

if you have any questions please ask as i do not get credit for my work until you rate us here at Justanswer

Customer: replied 1 year ago.
going to check connections now, be back in a few
Expert:  Gary replied 1 year ago.

sounds good

let me know

Customer: replied 1 year ago.
dose the under hood fuse box come out as one unit or does the top come off it when you remove the 3 bolts?
Expert:  Gary replied 1 year ago.

usually if they wont lift off all in one piece to flip it over then loosen the 3 bolts

Customer: replied 1 year ago.
I also have a 2003 1 ton work van would the BCM from that van be the same to swap out to see if it is the BCM. The 1 ton van has sealed beam headlights the 1500 van has composit head lights
Expert:  Gary replied 1 year ago.

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

Customer: replied 1 year ago.
Ok trying to get top off fuse box do I need to remove wire that are bolted to the cover 2 hot lines
Expert:  Gary replied 1 year ago.

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

Customer: replied 1 year ago.
am I only seperating the grey top of the box from the bottom half or removing the entire box?
Expert:  Gary replied 1 year ago.

just getting it up enough to find and test that wire and check the terminal

Customer: replied 1 year ago.
got box up are the wires in the plug and does it pull straight down
Customer: replied 1 year ago.
just need to know how connector comes off