Okay, Mechanics..

[Old Coastie]

I drive a 99 Dodge Ram 3500 van.

Brake and turn signals are a dual filament bulb, both sides are out. Bulbs are fine. Fuses are fine. Wiring harness looks fine, the length of the van.

Taillights and backup lights are seperate bulbs and work fine.

Where do I start?

 

[Cleanworks]

If you have side markers, they may be out.

 

[Bob Savage]

Use a volt meter to check voltages at the bulb sockets.

If no power, it could be a ground return in a '99 due to rust conditions.

 

[Old Coastie]

If you have side markers, they may be out.

All lights except the brake/turn bulbs are working fine.

 

[Old Coastie]

Use a volt meter to check voltages at the bulb sockets.

If no power, it could be a ground return in a '99 due to rust conditions.

Bob, The dual filament bulbs are supplied with three wires. I presume two supply and one returns. Any idea which color is used to ground? Black, perhaps?

 

[Lee Stockwell]

Ground somewhere.

Easy to confirm with a meter.

 

[steve_64]

Find a good mechanic.

Maybe stearing column.

 

[FB19087]

turn signal switch....or hazard switch

/

 

[Old Coastie]

The hazard switch makes the front turn signals blink, but not the rear turn signals. The turn signal does work for the front but not the rear. It does seem logical that there is a failure in the wiring going aft.

 

[FB19087]

its one of those switches........

 

[Johnny]

Short in trailer harness?

 

[hogjowl]

Surely you know a mechanic.

Make money with your time.

Goober

 

[dgardner]

According to the wiring diagram, those lamps share a ground with the license plate lamps. If they're out too, look for a bad ground.

 

[Old Coastie]

I doubt it is a goober problem. I don't drive a Chevy.

 

[Old Coastie]

According to the wiring diagram, those lamps share a ground with the license plate lamps. If they're out too, look for a bad ground.

Thanks, I'll look tomorrow.

 

[dgardner]

That ground point is supposedly on the left front fender side shield, if that helps....

 

[Old Coastie]

That helps a LOT!

 

[FB19087]

now you know where to start....follow that wire to the t-signal switch to the hazard switch....and repair the hazard switch

 

[dgardner]

According to the diagram I found the turn signal filaments are fed from the hazard switch but the stop filaments aren't - they're fed directly from the brake lamp switch. Never say never though....

 

[Cleanworks]

Although the bulbs may look good, they are probably not. Just replace them anyway and problem solved I bet. If I lose, I will buy you lunch anytime you are up this way.

 

[Old Coastie]

Ron, once I traveled all the way from Seattle to Scotland to collect on a free meal. But you're on!

 

[Cleanworks]

Anytime, you would be welcome, we have some real treats out here. My last dodge was a 1977 motorhome and I always had problems with all the running lights. it was usually a problem with the bulbs, or the sockets. Never the fuses or the wiring.

 

[dgardner]

I assume you have either replaced the bulbs or properly tested them with a meter. If not, then it is a good idea to replace as Ron suggests. I have also seen several bad sockets on vehicles that use the 3157 lamps like your Dodge. Do you have a test lamp or meter?

 

[steve_64]

My 2001 3500 had similar issues till I replaced the switch on the column. Replacing The computer made it run wayyy better too and fixed other electrical issues.

 

[Jack Zipper Zerkie]

If its only the brake lites look at the brake pedal there is a switch acuator that moves up and back as you apply the brake making the brake lites to lite jz.

 

[Old Coastie]

Ron was correct. I replaced all the bulbs after verifying that 1: voltage was going to the sockets and 2: the grounding block was undamaged.
Everything works fine now.

Thank you all for the very kind assistance and ideas.

 

[hogjowl]

Your welcome.

 

[Old Coastie]

You're.

You're welcome, hahaha

 

[Cleanworks]

next time we want a pic of you all lit up. pass the bourbon please.

 

[hogjowl]

No.
It's your welcome.
Not mine!