Mailbag: 1992 Eldorado, No Low Beams

[Cadillac Jim]

Hello i have a problem with my 1992 cadillac eldorado headlight low beam wont come on at all im pretty sure that circuit is not going tu the bulb i wonder if there is a separate relay for low beam and if it is where can i find it underhood in fuse compartment there is only one relay for headlight and when i turn the high beam on i can hear a click in it but not when i turn the low beam on could it be possible that the same relay for low and high beam work only for high beam?? thank u for ur help and time apreciate it

First reply:

The closest year factory shop manual that I have is the 1997. Others with more knowledge of the 1992 Eldorado will chip in. From the 1997 FSM, the 10 Amp MIRROR fuse provides the voltage for the signal for the dimmer switch. But I see four fuses for the headlights, one for each beam on each side, each 10 Amps. There is also a master 20 Amp HDLPS fuse that is probably the one you mention. There is a master headlamp relay and a high/low beam realy.

yea but the thing is that none parts no right and no left are coming on i dont think i would be so lucky to burn both fuses at t he same time but anyway i checked them all and they are all working i think the 1998/99 eldorado is almost the same cause i pulled a bunch of parts that fits mine 92 and on the fuse and rellay platform i think is that master headlamp rellay that you are talking about do u think itd possible the high/low beam relay to be somewhere else ??

thank u again for ur help

Second reply:

If my 1997 schematic for this circuit applies to your 1992 model, it's the high-low beam relay. My FSM says it's in the underhood fuse/relay area. If no one with a 1992 FSM steps up, I will look and see where it is in the 1997 models and upload that.

There is a second relay. This second relay switches the power from low beam to high beam. If its contacts are worn out on the low beam side, that would cause your problem. A relay is a $5 throwaway part.

I was looking for the relay on RockAuto and found that it seems to be part of the headlamp switch assembly. This contradicts my 1997 FSM which says the relay is in the underhood fuse/relay center. It would seem that you may be able to solve your problem with a new headlamp switch assembly. There are different configurations depending on whether you have fog lights, etc.

No i dont have fog lights no driving lights thank you a lot i will try to take the switcher apart and clean the contacts hopefully it might work ..

Third reply:

If you are comfortable with a volt/ohmmeter you can check the switch before you take it apart, or even take it out of the car. I strongly suggest doing that because we don't have a firm diagnosis. We haven't looked at the OBD codes yet, for example. The dimmer switch could be the problem too.

If you do need the switch assembly and will consider a new part, the part is a Standard Motor Products DS731. Whoops, I see that Rock Auto wants $235.79 for it. BUT Amazon wants $129.00 plus $2.50 shipping:

http://www.amazon.com/Standard-Motor-Products-DS731-Headlight/dp/B000C7XVOI

If someone with a 1992 FSM or who is familiar with the 1992 Eldorado headlight wiring would step in, that would be helpful too.

[Victor13]

yea u might be right i better i will check it first but i have to take the switch off anyway to check if the curent is going thru? or there is another wway to do it?