1998 cadillac deville. i do not have low beam headlights just high beams and daytime running lights. i replaced the high low beam relay and it did not fix it. could this just be the dimmer switch and if so where is it located on this vehicle thanks Tim

Sounds like you might need to replace your multifunction switch.

Headlamps Inoperative - Low Beams

Step

Action

Value(s)

Yes

No

DEFINITION: This diagnostic procedure should only be used if the high beam headlamps are operating properly and the low beams are inoperative.

1

Did you perform the Headlights System Check?
--
Go to Step 2
Go to Headlight System Check

2

1. Turn the headlamp and panel dimmer switch to the ON position.
2. Move the headlamp dimmer switch to the LOW position.
3. Backprobe the headlamp dimmer switch connector with a J 35616-200 from cavity A to ground.

Does the test lamp light?
--
Go to Step 3
Go to Step 5

3

1. Remove the daytime running lamp relay.
2. Connect a J 35616-200 at cavity G5 to ground.

Does the test lamp light?
--
Go to Step 4
Go to Step 6

4

1. Re-install the daytime running lamp relay.
2. Backprobe cavity B at the high/low beam headlamp with the headlamp dimmer switch in the LOW position.

Does the test lamp light?
--
Go to Step 7
Go to Step 8

5

Replace the headlamp dimmer switch.

Is the repair complete?
--
Go to Headlight System Check
--

6

Repair the open in CKT 359 (PPL) between the headlamp dimmer switch and the daytime running lamp relay.

Is the repair complete?
--
Go to Headlight System Check
--

7

Replace the high/low beam headlamps.

Is the repair complete?
--
Go to Headlight System Check
--

8

1. Inspect for an open in CKT 12 (TAN) between the daytime running lamp relay and S120, repair as necessary.
2. Replace the daytime running lamp relay if no open was found in CKT 12 (TAN) between the daytime running lamp relay and S120.

Is the repair complete?
--
Go to Headlight System Check
--

if replacing the high beam bulbs do not fix the DRL issue ,see my tip under 2001 to 2005 civic daytime module repair.The accord you have has the same module.

if you have to hold the switch so the high beams stay on then that indicates a bad/worn switch,you could have 2 problems the day time running light relay may have a problem with it.i would first replace the headlight switch at the base of the steering colume as by the info you supply its not changing to the high beam side without holding the switch in position.

Most probable cause is your headlight switch, but could also be the headlight relay (in the underhood fuse box).

Pull the head light switch and check it for out put.Do you have high beams?Check the low beam headlight bulbs.If you have high beams,and low beam bulbs are good,replace the dimmer switch.

Classic switch problem. Replace your switch and this will fix your problem.

Check fuses

possibly head lamp switch. daytime running lights on separate circuit and use the high beams at reduced voltage. does flash to pass work? that's high beams too. do high beams work?

Is it just low beams?
do taillights work?

If your car is running daytime running light system .. there is a DTR relay that goes defective and needs replacing ... I had the identical problem that was fixed with this replacement. The DTR relay is behind the glovebox.