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Macs
10-29-2009, 09:38 AM
I am trying to help an ederly woman that i work with fix her car. I do not have access to the car or this would be an easy diagnosis. Yesterday when she left from work her headlights did not come on. All other lights worked including highbeams. She checked her fuses and they were fine. So she decided to drive home with her highbeams on, but instead of them locking on she had to hold the lever on the column back. which i thought was very odd. I did some reading online and it appears to be the headlight switch on the dash or the headlight relay. It seems that everyone who has the same problem gets these two diffrent answers. If anyone has dealt with this please let me know. it is a 1998 Buick Century

Macs
10-29-2009, 10:33 AM
I did a bit more reading and it seems that when it is the headlight switch on the dash it will mess up intermittly and if it is the relay it will go out totally. So i am thinking the relay is the problem.

K87_250ES
10-29-2009, 11:06 AM
Looking at the wiring schematic (attached), my guess would be the headlight switch.
Holding back on the dimmer switch (Flash To Pass circuit) bypasses the headlight switch and grounds the high beams to turn them on.

Macs
10-29-2009, 11:32 AM
I am not seeing where the headlight relay is in that schematic, but from what i can tell the relay should be between the switch and the control module. So if the relay was infact bad it would basically have the same result as the switch going bad. The FTP lights use a designated circuit before that doesnt pass through any relays, correct?

I might be way off base and by the schematic i see how either one could be the culprit.

DeePa
10-29-2009, 12:03 PM
on my 96 pontiac sunfire, the multi function switch that contained the headlight switch went bad and i only had the pull option for high beams or just the normal dim running lights. no click on highs and no normal lows.

Not the same car but both close model years and by GM

K87_250ES
10-29-2009, 12:26 PM
The schematic is from alldata and it is very rare that it is wrong, but does happen. Looking at the headlight schematics for 97-99 Century the only relay I can find is for the foglights in the 99 model.
Depends on where the relay is located but typically a relay is between the power source and the headlight which allows the relay to take the load instead of the switch and it should be powered everytime the headlights come on. Also there would have to be at least one relay for each pair of lights, if this was the case it would be very unlikely for both to fail at the same time.
Without a schematic showing the relay I couldn't say for sure but I would still guess the headlight switch.

Macs
10-29-2009, 01:16 PM
I decided to use my lunch break and go check it out. From what i read on another forum, it has a relay for high beams and a relay for normal headlights. i had no idea where they were located and didnt see them in the big fuse block underneath the hood. So i removed a portion of the dash to check the switch. when i did, i noticed two relays right there by it. first i beat on the switch a bit then tried it, no worky. Then i removed the plug on one of the relays. I had to be very rough with it to get it out. I checked if i had power there and i did, fought like crazy to get the plug back in, tried it and they now work. So that was the end of my troubleshooting. I am unsure what those relays were to, but i guess it is possible that one was stuck, or maybe i bumped the switch just right or maybe a bad wire. It is hard to figure out what is wrong with something if it is working.

Dirtcrasher
10-29-2009, 05:18 PM
^ thats one bad thing about wiring diagrams, they show how it's wired but not where the components are located. I think it was Fabio that had a relay in some really screwed up and hard to get to area......

Mosh
10-29-2009, 08:29 PM
There is no relay in that system..

Look for it all you want..You wont find it.
Not on a 98 Century.

It is either the dimmer switch, in the steering cloumn, or the headlight switch.
Follow that schematic KE posted, and jumper a ground at the headlight switch for the low beams.. Cavity (D) Yellow wire..Clamp a jumper wire to the door jamb,and back probe that cavity at the headlamp switch.Turn the Igntion on...
If they work, replace the headlight switch..

If they dont work, it is a bad contact in the dimmer switch.In the steering column.