Hi all, I keep blowing the fuse for the brake lights on my 69 F-250. I replaced the fuse and one (light) worked right away and I got the other one working. Then I noticed that the wire for the parking lamps was unhooked on the one side so I reconnected that and now I have park lights on both sides, but when I step on the brake pedal it blows the fuse. Before I got the parklights fixed it only blew every 4-5 times. What is going on? A short or what? Also, if it helps any, I know it needs a new turn signal switch. Would that have any effect on it as the turn signals and brake lights use the same wire? Thanks in advance

 

J, My guess is you have a chafed wire that is shorting to metal somewhere. Find it and I believe you will solve your problem. Try looking where the wire passes through a frame hole first.

John

 

Your turn signal switch has EVERYTHING to do with it. If that is shorted, then that will blow the fuse also. If some of the wiring or the switch itself has problems, then this could be the reason for blowing fuses.

The brake light signal goes thru the switch since it has to interrupt that to one side or the other when the turn signal is activated.

 

OK thanks guys. After I thought about I figured it was one or the other (bad wire or the turn signal switch). I will continue to look for chafed wires and see what I find. Then I will check the turn signal switch. Thanks again

 

So, after crawling around under it for a while I didn't find any chafed wires. What I did see was two purple (near as I can tell.....you know.....36 year old wires and all) wires just hangin out in front of the bumper where everything splits off to the tail lights. So what are these for? I turned the park lights on and hit em with a test light but didn't get anything. Could they have to do with the turn signals? How do I test to see if I need a new switch? (I'm pretty sure I do as the front ones don't work) Thanks

 

So, I go to Advance Auto today after school to pick up a new turn signal switch and he goes in the back and comes back with a really small box. So I open it and look at it and say "uhh, I wanted a turn signal switch" and he said OK. So we ran through everything again and it was the exact part I had in my hand. He said that the TSS, wiper, and emergency flasher was in the same switch. So I said OK and paid and left. Is there anyway this can be right? What I got looks like it would indeed be the intermittent wiper switch, but I didn't know that they had the turn signals/hazards in them? I'm a little confused as I was expecting the one that goes in the column with all the wires and junk. Could someone help me out here? Thanks

 

It should be the one that goes in the column with all the wires and junk. The wiper isn't in the switch. That's down on the dash to your left. The brakes, tail lights and turn signals all go through there. It should have the little crescent shaped turn signal cancel cam in it. But it should have about 6-8 wires about 3 feet long hanging off it that run down the column. It should be about $60-70. Pull your steering whell off and look at the turn signal switch. Then you'll know for sure.

 

Yea, thanks qman. That's what I thought. Actually, its what I knew after I messed with it. So I'll go back tomorrow and see if they can get it right. Hopefully they have what I need. If they don't I have to go to Napa anyways.....

 

Napa was able to get me a new switch and I got it installed today (took me all of 45 minutes too). The brake lights work great - no more blown fuses. The only problem I'm having is that when I hit a turn signal the switch interrupts the power (like it's supposed to) only it doesn't give it power for a second to make it blink. Neither the front nor the rear lights do anything. The emergency flasher is also good, as they work properly then. Anyone know what I can do to figure this out? Thanks

On a side note - that bone stock 390 sure was runnin' good this afternoon!!!

 

FWIW: Just make sure on any bulb that uses two wires that it takes a 1157 bulb, because both those wires have to be hot with a separate ground. It is possible that the two positives were mixed up. When you put your parking lights on with the vehicle running they should be much duller then the brakes lamps.

 

Check the flasher first, usualy they stay on or don't work at all. Just swap it with the hazard flasher if that changes the problem it's probly' time for a new one.

 

Yep, got 1157 bulbs in it and the brake lights are much brighter than the park lights. If I have the park lights on and step on the brake and hit the turn signal then the side that should be blinking just has the park light on. With no park lights on that side just goes out. Nothing happens in the front. Maybe I need to look up there? Also, as I said in my previous post, the flasher is good and they work like they should. One thing I noticed is that the arrows on the dash don't light up like they should when "signaling", but they do with the flashers. Maybe the problem is under the dash somewhere?

 

Double check t/sig wiring at connector, new switches can have confusing colors.

 

While I was messing with a test light today I found that the only "hot" wire while not on the brakes etc was the blue/yellow (horn) wire. All fuses are good. Shouldn't there be another hot wire going into it too? Or is it just when you step on the brake? With the key on I get nothing except for the horn wire. Hit the brakes you get some more, hit the emer flash and you get more. Hit a turn signal and you lose a couple. What could be going on?

 

blue wire is from the flasher that should be hot or when you test with a test light the idicators will flash.....brake is red\black hot with pedal depressed.....

signal right turn should have continuity between blue and green and green white....signal left and continuity goes through blue to yel blk and wht blu which are the left signals

check your fuses again or see if you have power going into the flasher