Hi, I have a 2003 Ranger 4x4 4dr XLT with a 4.0 L Auto.
Last year I had a pioneer deh x6700bt radio installed by Best Buy, and everythings been working fine. Then 2 weeks ago I lose my instrument lighting, parking/ running and fog lights. The headlights, turn and brake lights all work and so does the radio.
I find the 15A fuse (#33 under hood) has blown, but keeps blowing every time I turn the lights on.
After checking the forum, I took the dash apart, check wires and put a new light switch in, blows the fuse, disconnected the dimmer and 4x4 switch, still blows the fuse. Remembering the forum mentioned problems with aftermarket radios, I disconnected the radio and... TA-DA, turned on the switch and the fuse didn't blow. From what I understand there is some issue with the red-blue illumination wire and it doesn't need to be connected?


MY QUESTION IS: Why after almost a year after the after-market radio being installed would this cause a problem? Any ideas?
AND; should I disconnect the red-blue from the radio?


Appreciate advice, thanks.

 

It reads like the Light in the Radio is shorted out now.

The Light Blue/Red stripe wire in the Rangers Radio wiring harness would be the one to disconnect, at the radio, until you have time to pull out the Radio and see if you can fix the internal short.


But you said you unhooked the Dimmer, which feeds ALL the instrument light(dash and radio) via the Light Blue/Red wire, and fuse still blew?

#33 fuse sends power to Main light switch, Tan/white stripe wire
That power leaves the main switch on a Brown wire that goes to Dimmer AND parking lights.
Dimmer power goes out to several "back lights" including Radio, via the Light Blue/Red wire.

Also to confuse things a bit #33 also feeds the High Beams, but NOT the low beams, which is why the head lights still worked

 

Unhook the offending wire from the radio, and be sure to tape both ends off with some good electrical tape if a new radio is out of the question.

It's best to fix the underlying problem instead of just putting a bandaid on it like this, but for circuitry of this caliber, heh, not happening. If you have a warranty, use it.

Do consider that if one area is starting to fail, other areas may fail soon as well. I would advise getting a new unit asap. If one cannot be obtained for whatever reason, I'd recommend disconnecting it entirely from the truck's harness.

 

Thanks gentlemen. I don't know what in the radio may have shorted, it still was working fine while the rest were out. Crazy.
I realized it did happen after I needed to use the 4x4 earlier that day.
I may change the 4x4 switch, just to be safe. I don't know if I damaged it when I took it out.

 

The 4x4 hi and low lights do run through the dimmer switch, if that means anything to you.

 

The Back light in the Radio would be where the short was/is, if that's the issue.
In Radios with LED displays the back light is usually for the buttons, they are lit when dash lights are on, via that Light Blue/Red wire.

So Radio will "work fine" if that #33 fuse is blown, but it wouldn't have back lights at night.

radios have 3 "power" wires:
1. 24/7 power, always powered, keeps clock and radio presets working when key is off
2. Key on power, turns on Audio portion of radio when key is in RUN or ACC
3. Lighting power, powers the back lights in Radio for use at night, and Dims or Brightens with Dash Light dimmer control.

Some 3rd party Radios don't have the back light option, all the lights are on when radio is on, they don't hook up to the vehicles lighting control, just to the 24/7 power and RUN power, these have their own Dimmer control.

 

Thanks, that was very helpful, I didn't notice whether the buttons were lit. I'll check that out first, but I must make the truck usable at night. So I'll go with the bandaid.

 

Thanks Ron. Yes the buttons were not lit. Knowing that was the problem, I felt confident disconnecting the red/blue wire. Everything works good now and I don't care if the radio buttons aren't lit, as long as the radio works,. I need to try out the 4x4 switch but at least I don't need to tear the whole dash apart to replace that.

 

Thanks for the update

 

Hi there, well my gremlin is back, the #33 EC fuse is back to blowing.
Nothings been changed or messed with.
Pulled fuses in the SBC to see if the problem was there, nothing.
#33 pops as soon as I turn the switch to Parkng lights.
Could it be the 4x4 switch or the fog lights?

 

it could be the fog light circuit, but not necessarily the 4x4 switch, only the back lighting for the switch.

 

Thanks.
Recently I left my lights on for 6 hours and of course the battery went so low that it couldn't turn the engine, just clicked when I tried to start the engine The AAA guy checked out the battery health for me ( he was hoping it went bad so he could sell me a new one for probably$150) but the battery is good and it took and kept the charge.
RonD stated that my 2003 Ranger should have a shut-off relay, but either my Ranger doesn't have it or its gone bad, because my lights don't turn off in 20 minutes or 6 hours.

As mentioned, I am having issues with the #33 EC fuse blowing as soon as I turn the light switch on to park/running lights. This results in my dash lights, running lights an fog lights not working. Supposedly, I'm told that my low beams should work, (they do) but not the high beams (but they do work).
I will look into the fog lights and switch today.
I trouble-shot as many possibilities ways that I can think of with no success, only lots of blown fuses.

Is it possible this relay could be the culprit or part of the problem?
Where should this relay be located?

 

The battery saver circuit does not cover the headlamp or park lamp circuit. You can leave those on until the battery has no charge left and they will never turn off.

The battery saver circuit only applies to the dome light and I believe the cigar sockets.

 

Yes, Articwolf is correct, my mistake.

Although Battery Saver Relay seems a bit over rated if it doesn't actually save the battery when the most common cause of drained battery, leaving on the head or parking lights, isn't cut off, lol.

Seems it only cuts power to interior systems
Head Light switch/system is separate

 

It doesn't make much sense as to why it doesn't cut the headlights or parklights. One of Ford's "Duh" moments lol.

 

I have tried so many tests, used a box of fuses, replaced and disconnected switches & relays, but this gremlin can't be found, the #33 EC fuse still keeps blowing as soon as I turn the switch to Parking/running lights.
Any further ideas where the issue might be.
I need help before I get a ticket

 

switches and relays are rarely the culprit. You're only wasting money doing that. Have you checked the sockets for corrosion or looked along the wiring harnesses for damage?

Has the vehicle been involved in an accident?

 

thanks for the quick reply. Yes the truck was in an accident about a year before this problem arose. I have checked the fog and parking light wiring in the front. Also the problem arose about a month after I had the dash apart replacing the instrument lights (only 3 were working). I was advised to cut the ground on the trailer plug, which I did but had no affect. Then I was then advised to cut the blue wire on the aftermarket stereo, which I did and that did the trick.
About a month later I tried to tow a trailer but the trailer plug ground was still cut so I reattached it on the assumption that when I cut it previously, it did not make any difference. Not so, the #33 fuse blew, then when I cut the trailer plug ground again it didn't make a difference, the #33 fuse still blows.
I'm going to change the headlight switch and check it's socket, also trace the trailer hitch plug cable back to the next connection.
If that doesn't work, I guess I'll have to break down and take it to an auto electric specialist.