I am having a problem with my dashboard lights blowing fuses. I bought an 87 Ranger XLT, and found that the dash lights didn't work. The 5 amp dash light fuse was blown, and the dome light would not come on using the switch. I replaced the fuse with a 15 amp and replaced the headlight switch which had melted the connector at one of the terminals. The dome light now comes on using the switch and I was able to get the dash lights to come on at a very low setting, but the headlight switch will smoke some. But when I turn the switch to brighten the dash lights, it causes the tail light fuse to blow. I don't see how the dash lights could blow the tail light fuse, but it happens as soon as I install a new fuse and brighten the dash lights. Any ideas as to what is going on? I think it is probably a short somewhere, so I pulled the instrument cluster and looked at the wires, didn't see anything exposed.

Please help!

 

Definitely a short. 5-amps is a lot of current to draw - putting the 15-amp fuse in is asking for a fire to happen.

I've seen this kind of behavior with improperly installed accessories - I'd check to see if it has (or had) a set of fog lights, driving lights, etc mounted and, if it does/did, trace the wiring back to the possible cause of the short (check thoroughly under the hood.) Check under the dash and around the cab for anything that may have been "added on" later by previous owners - radios, amplifiers, lights, etc. - if the add-ons were removed but the wiring was left behind, that could be part of the problem...

Just a thought, but that's where I'd start...

 

Thanks, I'll check around for exposed wiring. Yeah there was a cheapo radio in there that I replaced, and the wiring harnesses for the factory radio had been cut and the radio connections were just twisted together. But I soldered the new radio connections and taped everything up so nothing is exposed. But it is still blowing fuses. I guess what threw me is that the dash lights were causing the taillight fuse to blow, but they are 2 separate fuses/circuits.

I thought about just running a new wire from the dashboard lights to the switch, but if there is a short somewhere else, that won't help.

 

Also, I thought about just putting in some small LED lights that shine on the instrument cluster for night driving. Does anyone know if this would pass a state safety inspection? I am in NC

 

Automotive wiring can be a PITA to diagnose... Case in point - my wife once owned a '75 Dodge van - one day, the taillights died - all of them - there were no lights, no brake lights, no backup lights, nothing - the entire back-end of the vehicle was without light of any kind...

I fought with that thing for days - checking wiring, sockets, fuses, etc. Hell, I even swapped out the entire fuse block as I was getting frustrated and was grasping at straws at that point...

During all this, I happened to notice that the heater switch was having issues so, I decided to replace it while I was doing everything else. Turns out, replacing the heater switch got the lights working again! Don't ask me how, but it worked and I was finally a happy man... Only thing I could figure was that, somehow, the heater circuit was drawing power away from the lighting circuit and caused the lights to quit working... Damnedest thing I ever saw...

Something that came to mind about your issue, though, since things have melted - wiring doesn't have to be exposed to short - if you have wiring in a bundle or in a pair (as in speaker wiring, for example) and that wiring gets hot enough, it can "fuse together" (insulation melts together) and cause the wiring inside the insulation to short out with other wiring - I've seen it happen and, unless you're really looking for it, it can be a major pain to find... With the dash lights affecting the taillights, I'd see if I can find the wire bundle that those 2 circuits run through and carefully inspect it...

Just some thoughts to ponder... Maybe someone else has an idea or two...

 

Some people have real trouble with reassembling the dash on older rangers, if somebody has been in there, look for a light blue with red stripe wire running to the radio harness, this is the dash illumination wire and may be shorted out by some "car stereo installer".

Seen it more than once.

 

Okay I will, thanks! I was planning on checking behind the stereo again. Since the entire dash interior is metal, it would be very easy for a cut wire to ground out in there. And I seem to remember that I was able to get the dash lights to work fine while I had the dash apart and stereo out.

Also, I replaced the turn signal switch last night, since the switch wouldn't catch half of the time, and that fixed that problem. But I did notice that the plastic wiring connector (top one) was slightly melted on top beside one of the terminals. So it looks like over the years, various things have overheated and melted on the truck.....if I don't find anything behind the radio, I am definately going to unwrap the wiring bundle behind the fuse block and look for melted wire insulation.

 

my 87 rangers directional lights and heater wont work when vehicle is on but will run everything perfect in accessory mode so idkwhat the problem is I just got a new alternator and got it checkout for voltage its all good but can not figure out problem


ideas?
battery is 1-2 years old
recently grandfather installed flood lights could that be problem? bad accessory installation?
plz respond

 

Hiya, apologies for jumping on an old thread, but this is all very similar to the issues I am having with my 86 Ranger XLT, and I hope you nice people can help.

Just like the OP, I bought a truck whose dash lights don't illuminate. There was no stereo, but a previous owner had cut the stereo wiring and used connecting blocks to hook up modern stereo wiring.

At the switch, there is power going to the blue w/ red stripe wire, which I understand is the feed to the dash lights. There is also power going to the red w/ yellow stripe, which I think is to the dimmer switch. So that all seems good.

I also changed the dash bulbs and fuse. But still no dash lights.

I read the comment above, and checked the stereo wiring. Sure enough, there is a blue w/ red stripe incorporated in to the mess. It comes out of the same 4-wire cluster that (if I am correct) contains the stereo's permanent live and switched live (green w/ yellow, and yellow w/ black), so I can understand why they may have done this.

This blue w/ red wire shows as live/dead when I turn the light switch on/off, so it seems I'm on to something. But what I don't understand is where this wire would have fed to, had they not chopped through it. There are no loose wires that I can see.

Can someone please enlighten me as to where/how that wire should feed to, so power gets back to to the dash bulbs?

It may be unrelated (and if so, I really don't care at the moment), but the stereo switched and permanent lives aren't getting power, and the fuse is fine.

Your help would be much appreciated, so I can drive at night...

Thanks!

 

[QUOTE=AaronEZ;11092180]I am having a problem with my dashboard lights blowing fuses. I bought an 87 Ranger XLT, and found that the dash lights didn't work. The 5 amp dash light fuse was blown, and the dome light would not come on using the switch. I replaced the fuse with a 15 amp and replaced the headlight switch which had melted the connector at one of the terminals. The dome light now comes on using the switch and I was able to get the dash lights to come on at a very low setting, but the headlight switch will smoke some. But when I turn the switch to brighten the dash lights, it causes the tail light fuse to blow. I don't see how the dash lights could blow the tail light fuse, but it happens as soon as I install a new fuse and brighten the dash lights. Any ideas as to what is going on? I think it is probably a short somewhere, so I pulled the instrument cluster and looked at the wires, didn't see anything exposed.

Revised 07-04-2023

My dash lights just didn't work. All my idiot lights did. It was dimmer or bulbs. Dimmer was sloppy. Cleaning it did not improve function. Replaced dimmer. No joy. I mean all the bulbs?

Took out cluster and removed a dashlight bulb. Black. Took out like all 13 dimmer bulbs. All black. No aftermarket bulbs. FOMOCO ordered them and it cost A LOT.

Dash lights work. I'm happy.