Hey guys , new to the forum just bought a ranger yesterday 2004. 2.3L
everything was fine , I flipped on my headlights switch and I started hearing a weird buzzing noise sounding like it was coming from the fuse panel inside the cab. While the lights are on the blinkers and wipers will not work . if the wipers or blinkers are on and I turn on the headlights they will shut off. The blinker indicators are solid non flashing while headlights are on . I just have no idea where to start. If I turn on every single thing you can actually hear the truck bogging down. Also the light dimmer switch will quiet the buzzing if I dim the interior lights completely. Any Idea where to start would be appreciated. It also sounds like there is a clicking noise . Was wondering if maybe the whole inter cab fuse panel is junk ? Or the flasher relay under the dash or what the heck. Thanks

 

Welcome to the forum

Unfortunately, 2004 was the first year of the HEC(hybrid instrument cluster) and the SJB(smart junction box, body computer) and this makes "simple" diagnostics a real pain

There is no direct connection between the dash turn signal lights and the head lights
Are all 4 turn signal bulbs also on or just the dash bulbs?

Try this
In the cab fuse box(thats the SJB behind that) pull out fuses 3 and 4, thats the left and right head light fuses
Then see if turning on the head light switch still cause turns to stop

Trying to see if its a ground issue in one the the head light bulbs
The HEC has a mini-computer, and it turns on the turn bulbs, when told to by the Turn signal stalk(multi-function switch)
If the outside turn bulbs are also on the the multi-function switch may be at fault

Also try pulling out cab fuse 17, it for 4-way flashers, turn signals should still have power
And see if turn on head lights still kill turns, looking for a flasher issue

 

All 4 signal lights are on , not just the dash lights . I will trouble shoot those fuses in the morning. I'm also scratching my head as to the noise that's coming from the fuse panel inside the cab when the lights are on.
I appreciate the insight and will update tomorrow.
if pulling fuses 3 and 4 and the blinks still kick out when turnitn the headlights on what would that suggest the issue be ?
thanks again for the quick response on the forum .

 

Ok , I did some trouble shooting this morning , pulling alm the fuses you said and the blinkers still go solid on when I turn on the lights , along with the buzzing noise coming from the fuse panel area in cab . I tried both the flasher fuse and the headlight fuses both had the same out come . Would that mean multi function switch?

 

Well the head lights don't go thru multi-function switch, high beams do, but there is no cross over connection between high and low beams, high beams don't even go thru main light switch(because of flash to pass function)
You can see if flash to pass effects turn signals, main light switch OFF

The noise is most likely the flasher if turn signal bulbs are all on

As a last resort................lol, disconnect battery cable for 5-10 min, that will cause all computers, PCM, SJB, HEC, to reboot factory software when powered back up, same as any electronics, unplug it from power and REBOOT, when there is a problem, lol
You will lose radio presets

 

So today I replaced the flasher relay and the entire fuse panel inside the cab. As soo as I turn my head lights on it does the exact same thing. I am scratching my head here. Bad ground ? A short in wiring , trailer light short ? I took a video of the sound cant figure out how to upload it though. Lol

 

You replaced the SJB?

 

Yes, I replaced the sjb this morning. And the flasher relay . Pulled both from a salvage yard.

 

Then its even more of a puzzler

I will post the wiring diagrams for the turn and head lights, maybe you can find a crossover that makes sense