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Strange Headlight Problem Need Help

840 views 5 replies 3 participants last post by  Nato740 
#1 ·
On my 1997 960 wagon the bulb out light is on telling me a lightbulb is out,should be a simple fix right,wrong. Turns out the passenger side headlight is out,so I replaced the 9006 bulb with two different brand new bulbs one from Philips and the other from Syvania neither one solved the problem. Checked the socket for voltage with meter and got 12 Volts with Ign. on and headlight switch on, so I then check for continuity on both of the bulbs they check out fine. I am truly stumped at this point so I pulled the working bulb from the driver side and install it on the passenger side again no light. Checked for voltage at passenger socket again and find that I still have 12 volts but none of the bulbs will work. Am I missing something? Need help guys I cannot for the life of me figure this one out.
Thanks for the help in advance.
 
#2 ·
Re: Strange Headlight Problem Need Help (andy29902)

Read your post. Think you did almost everything if i read right, but one thing. Try finding the (last i saw mine it is round) Bulb Out Relay. It is BIG too with lots of wires and pins. Last ditch is this is bad. AS all the POWER and GROUNDS i remember run thru this thing. If the right side head light curcuit is bad then it will not light. CAN be either the power or the ground! Thats makes them NOT light and throw a bulb out code. My 744 does this ALL the time with tail lights loosing grounds in the board the bulbs are in. I let it go for a few days till i see if it comes back. Then I go in trunk and wiggle the side that is out. Most times it comes right back only to go out in a week or so again. Very rarely do i need to change a bulb. Also it is not always the same bulb or side. But most times it is the right side on my car. And most times it is one of the two parking lights or the brake light. Worth a try for you and your head light right? http://********************/smile/emthup.gif
 
#4 ·
I have Voltage at the connector until I plug in the bulb then it seems the circuit loses all voltage, this happens with several different bulbs. Ihave even taken the wires out of the connector and attached them to the bulb with the same result. Has me truly Baffled
 
#5 ·
Re: (andy29902)

The bulb-out sensor may be allowing power to the headlight socket when you check for voltage BUT may be mistakingly sensing a bulb failure and not allowing power through the sensor once a bulb is plugged in to the socket. Other areas to check are headlight switch and ignition switch.

George Dill
 
#6 ·
Re: (andy29902)

Like I said change out the BULB SENSOR RELAY. Put in a known GOOD one. Then see if you got lights. With no load (bulb out of harness, open loop) you might GET power at the plug. But with load (bulb in harness, closed loop) RELAY might fail out internally and throw the code and not light bulb. HENSE a BAD REPLY. http://********************/smile/emthup.gif Only other thing you might try is to find if you got a good ground. Reverse test the ground in the headlight harness. Hook the same test light to a known good power source and use the probe to now test the ground to make a closed loop and light test light/probe backwards form how you tested the power to the bulb before.
 
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