Short to power?? Headlights always on, truck won't start

[jaronpham]

I recently was working on my transmission, exhaust, and transfer case and in process have somehow created a new problem. My 93 Ranger 4.0 won't start (will crank but wont turn over) and there seems to be a possible fuel delivery problem? A clue is that now the headlights won't turn off, pointing to a short in the system somewhere. Possibly drawing power from fuel system and not allowing fuel pump to work correctly?

I've searched for the short, wiggling harness and connectors while my dad watches the headlights to see if they flicker.....nothing seems to work.

Any ideas?? I'm stuck here and no shops want to take on the project or there's weeks of waiting.


Thanks

 

[Curious Hound]

I’ll study the EVTM when I get home Tonight. @RonD may come up with some ideas faster than me.

 

[jaronpham]

I’ll study the EVTM when I get home Tonight. @RonD may come up with some ideas faster than me.

Thank you tons! I'll wait to hear from you, still searching for the issue as we speak

 

[RobbieD]

Do you have a Canada-spec truck, with DRL (Daytime Running Lights)?

Headlights not turning off on a '93, I can only think of a failed headlight switch or possibly a DRL module, if present.

Not sure if "flash to pass" is constant power (i.e. no ignition "on" needed), but you might try working the combination switch (low, high beam, flash to pass) when you're troubleshooting it.

 

[jaronpham]

I’ll study the EVTM when I get home Tonight. @RonD may come up with some ideas faster than me.

Okay, the inertia switch had been flipped. Reset and truck started up. Headlamps still always on though...????

 

[jaronpham]

Do you have a Canada-spec truck, with DRL (Daytime Running Lights)?

Headlights not turning off on a '93, I can only think of a failed headlight switch or possibly a DRL module, if present.

Not sure if "flash to pass" is constant power (i.e. no ignition "on" needed), but you might try working the combination switch (low, high beam, flash to pass) when you're troubleshooting it.

Hmm interesting. I'll take a look and maybe give the combination switch a a wiggle. Perhaps that's the issue. Not sure if you saw my latest reply, but I discovered the inertia switch had been flipped, I reset it now and the truck started up. Lights are still always on though!

 

[RobbieD]

Just headlights, no parking lights?

 

[Uncle Gump]

I would check the headlamp switch and connector... I've seen a few melted.

 

[Uncle Gump]

I also moved this to the lighting forum...

 

[jaronpham]

Hi

Just headlights, no parking lights?

yes just the headlights. also, do you know where the DRL module is located on a 93 ranger 4.0? can't seem to locate it.

so strange, I narrowed the issue down to me bumping the inertia switch while wrestling the exhaust manifold. I can start the truck now but cant get these damn headlights to turn off. Maybe I need to reset something

 

[Curious Hound]

Ok. My first reaction is that if you have the daytime running lights module (DRL), as mentioned above, that is a likely culprit. Is it high beams or low beams that are on? The DRL energizes the high beam filaments. It looks like you can disable that feature by removing its fuse in the engine compartment fuse panel. It's a 15 amp fuse near the middle of the panel.

As Uncle Gump mentioned, the light switch is prone to o reheating and melting on many of these trucks. That's a possibility. But in my experience, that normally causes the lights to NOT work. The contacts usually burn open so power can not pass to the lights. There is a slim possibility that the contacts welded shut. But it's less likely.

I'm curious. Can you switch from low beams to high beams and back?

 

[jaronpham]

I also moved this to the lighting forum...

thanks. ever heard of any issues w lighting happening after an inertia switch being flipped?

 

[Curious Hound]

The DRL module, if you have it, is located behind the driver side headlight.

 

[Curious Hound]

thanks. ever heard of any issues w lighting happening after an inertia switch being flipped?

They are not related except that they are both in the same vehicle.

 

[jaronpham]

Ok. My first reaction is that if you have the daytime running lights module (DRL), as mentioned above, that is a likely culprit. Is it high beams or low beams that are on? The DRL energizes the high beam filaments. It looks like you can disable that feature by removing its fuse in the engine compartment fuse panel. It's a 15 amp fuse near the middle of the panel.

As Uncle Gump mentioned, the light switch is prone to o reheating and melting on many of these trucks. That's a possibility. But in my experience, that normally causes the lights to NOT work. The contacts usually burn open so power can not pass to the lights. There is a slim possibility that the contacts welded shut. But it's less likely.

I'm curious. Can you switch from low beams to high beams and back?

hi, thanks for your interest in my fiasco.

I have been playing w that 15amp fuse throughout the day, when I pull it the lights turn off.

It seems to be the lowbeams that are always on. Which is even more strange, if what youre saying is true about the DRL energizing the high beams.

Is that 15 amp fuse specifically for DRL? would be be bad practice to just pull that fuse permanently and call it a day?