need some electrical help if possible.... - PeachParts Mercedes-Benz Forum

rebreath · #1 02-19-2008, 03:10 AM

heres the problem as found so far.....
friends 84 300D turbo was a padiddle(1 eye) so it was time to fix it.also both fog lights were out..so...
pulled one fog light....hmm,looks ok.....pulled other fog light,also looks ok(realizing that looks deceive with light bulbs i will test in the am).so on a whim i take the "bad" headlight and plug into socket with working light and lo and behold,both lights are good.
Put the tester to the light sockets(both fog and both lights) and only get voltage across drivers side low beam.but when i push the high beams on i get voltage across both sockets.No voltage to fogs from either setting,even with center of knob pulled out(front fogs on) one click.when the stick to turn on highs is pulled(as opposed to pushed) to "flash" the high beams I get nothing anywhere.
light switch on=padiddle(drivers side)
light switch on and center pulled one click=padiddle(ds) no fogs
light switch on and stick pushed forward(high on)=both high lights work
light switch on and stick pulled(flash high)=no high lights work
no fogs throughout.
also checked that no light equaled no voltage,not burnt bulb.
So far(at 2am) all sockets and wires seem healthy.anywhere in particular that I might start looking?any relays(ice cubes) to check.loose solder somewhere that needs rewelded.cant inspect his car until this is fixed.
any and all thoughts will be appreciated.

automch · #2 02-19-2008, 08:05 AM

Quote:

Originally Posted by rebreath

heres the problem as found so far.....
friends 84 300D turbo was a padiddle(1 eye) so it was time to fix it.also both fog lights were out..so...
pulled one fog light....hmm,looks ok.....pulled other fog light,also looks ok(realizing that looks deceive with light bulbs i will test in the am).so on a whim i take the "bad" headlight and plug into socket with working light and lo and behold,both lights are good.
Put the tester to the light sockets(both fog and both lights) and only get voltage across drivers side low beam.but when i push the high beams on i get voltage across both sockets.No voltage to fogs from either setting,even with center of knob pulled out(front fogs on) one click.when the stick to turn on highs is pulled(as opposed to pushed) to "flash" the high beams I get nothing anywhere.
light switch on=padiddle(drivers side)
light switch on and center pulled one click=padiddle(ds) no fogs
light switch on and stick pushed forward(high on)=both high lights work
light switch on and stick pulled(flash high)=no high lights work
no fogs throughout.
also checked that no light equaled no voltage,not burnt bulb.
So far(at 2am) all sockets and wires seem healthy.anywhere in particular that I might start looking?any relays(ice cubes) to check.loose solder somewhere that needs rewelded.cant inspect his car until this is fixed.
any and all thoughts will be appreciated.

Check your fuses. Each light is individually fused for both the high beam and the low beam. These commonly corrode on the ends and loose connection. Sometimes rotating them in their respective holder will suffice. Other times you will need to remove them and wire brush the fuse holder. If you look at them it will not be readily visible unless the corrosion is really bad. Take them out to inspect each one.

I also recommend coating the ends of the fuse and the fuse holder with "Trucklite" brand electrical corrosion protector. Most truck parts houses have it. Works well on bulbs and sockets also. HTH

Diesel911 · #3 02-21-2008, 01:28 AM

Quote:

Originally Posted by automch

Check your fuses. Each light is individually fused for both the high beam and the low beam. These commonly corrode on the ends and loose connection. Sometimes rotating them in their respective holder will suffice. Other times you will need to remove them and wire brush the fuse holder. If you look at them it will not be readily visible unless the corrosion is really bad. Take them out to inspect each one.

I also recommend coating the ends of the fuse and the fuse holder with "Trucklite" brand electrical corrosion protector. Most truck parts houses have it. Works well on bulbs and sockets also. HTH

Ditto. 2 days ago the front passanger and driver side rear electric windows would not work. They both use the same fuse but the fuse looked good. After twisting the fuse side to side some of the oxidation came off exposing the bare metal on the fuse and the windows now work.

tangofox007 · #4 02-19-2008, 08:49 AM

Quote:

Originally Posted by rebreath

.
Put the tester to the light sockets(both fog and both lights) and only get voltage across drivers side low beam.but when i push the high beams on i get voltage across both sockets.No voltage to fogs from either setting,even with center of knob pulled out(front fogs on) one click.when the stick to turn on highs is pulled(as opposed to pushed) to "flash" the high beams I get nothing anywhere.

By design, the fog lamps do not operate when high beams are selected.

The passenger side low beam and both fog lamps are powered through the same fuse. The driver side low beam and both high beams are fused separately.

If an '84 is the same as an '82, fuse F11 would be a good place to check.