Headlights wont work on 1998 mustang v6 Running lights brake lights and gauge lights work fine. The lights only trn on when i hold the high beam switch. Any suggestions?

" dim headlights "? None of your lights should be 'dim'. You have 4 lights.

Side Lights.
Daytime Running Lights (DRL)
Low Beam Headlights.
High Beam Headlights.

Here are the fuses, check fuse 5 and D although they covers more items than lights. Your best bet is to find a good local auto-electrician.

1994-1998 Ford Mustang Fuse Box Diagram

https://knigaproavto.ru > ... > Ford > Mustang

17 Oct 2019 - Fuse Panel Diagram Ford Mustang Mk.4 engine: 3.8L, 4.6L, 4.9L, 5.0L and 5.8L (1994, 1995, 1996, 1997, 1998)

More here

https://www.google.com/search?q=1995+ford+mustang+gt+v8+low+beam+headlight+not+working

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Replace the switch on the steering Colum it has gone bad not a big deal to change.

Hi, check you bubble or replace it.

sounds like the headlight switch is defective and needs replacing,but you need to check to make sure the rod that the switch pushes against if make the full travel and not short as this will not allow the switch to change from low beam to high beam.if the rod is travelling the full length then the switch is no good.you should also hear a click when moving the arm to go from low to high if not then the switch is bad.by holding the lever at a certain position to get the high beams to work this also indicates a switch problem.

Get a schematic and trace out the power source to those devices not working.

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.

Is this both the high beams and low beams that do not work ?

If you checked all 3 fuses with a meter ( with the headlamp in Low position for both low beam fuses or in high for the high beam fuse ), the next items to test are the MFS ( MultiFunction Switch ) and the main headlamp switch ( test not look at it ).

The main headlamp test chart


The test chart for the MFS

check wiring

https://s1.postimg.org/1i7q5btlu7/headlamps.jpg

Click on the link.
The top wires to headlamp are voltage for hi or lo beam.
The bottom black wire is ground. You can use a test light to check voltage and ground.

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