Fuse Box Help

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Fishthatkills

Fishthatkills

Fish that kills
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Hey folks,
I have a 67 cuda that keeps blowing the brake/dome lamp fuse. I checked the amps on the fuse holder itself without a fuse and I am getting 1.88 amps. If a wiggle the blades I will get 25.7 amps briefly! What gives? one side of the fuse holder seems loose, is that causing my trouble you think? I took the screw holding the box out but can't seem to flip the box around to see the other side. Are there replacement fuse boxes available?, and if so are they a pain to install? It looks like one side is hard wired in and the other has a connector that leads to the instrument cluster wiring. Not to mention a whle mess of other wires that I can't tell if they are part of the box or not!

I should mention that this has never happend before and I have had the car on the road two and a half years.

Any advice would be helpful! Got to get the car ready for the Lone Star HotRod Round-up!

John B. :sad10:
 
What kind of vehicle are we working on?

There are two possibilities, one of which does not match with your high amperage reading.

When the ONLY problem is a loose/ broken/ corroded fuse holder clip, that bad connection will make HEAT which will blow the fuse, possibly melt insulation off the immediate wire, as well as the fuse box

But if you are REALLY getting 25 amps, that indicates a short somewhere, because there should be nothing on that circuit to draw that much.

It appears that this fuse (depending on year) feeds dome, stop, tail, and emergency flashers.

DO YOU HAVE A SHOP MANUAL, and WHAT YEAR /MODEL are we working on??
 
It does sound like a short somewhere.I would trace your wires,starting from the back(taillights)and work your way to the fuse box.Look for pinched wires under your scuff plates,kick plates.Hows your little dome light switches(little pins on the door post)?Do they work correctly?Just some ideas to try and help find your problems.
 
I had the same problem with my 67 fish. I think your problem may be at the top of the fuse holder box. You have to remove the 1 fat screw and pull the whole assembly down enough to get a look at the top. Carefully remove the plastic cover and look inside. Either something metal got in there or your existing tabs are touching each other possibly due to a wire that got pulled too hard. If you're really pulling 25 amps intermittently something's loose.

good luck.
 
find the two flasher units under the dash....make sure they get put into the holders,one is on the pass side of the ashtray and I'm not sure where the other one is.....that would be the one that on my duster fell down and was touching the metal of the dash frame and kept blowing the fuse for my brake and interior lighting intermittently :grin:
 
I took and flipped the fuse box and took the cover off. Did not see anything wrong there. Fiddled around with both flashers and made sure they were tight,. put everything back as it was and replaced the fuse again. Now everything is back to normal, for now! I hate these kinds of problems, intermittent stuff sucks. We will see!
I also checkes the tail light sockets and wiring as well as the post interior lights too!


Thanks for the suggestions!
John B.
 
Yepp I had checked everything a few diffrent times and never found the problem,one night I was layin under the dash.....drinking it over so to speak and was listnen to the stereo and then I saw the spark and the stereo went Kapuuht and it was the flasher had fallen out of its holder and the problem has not been back in over a year,glad ya got it goin again enjoy the ride!!!!!
Fishthatkills said:
I took and flipped the fuse box and took the cover off. Did not see anything wrong there. Fiddled around with both flashers and made sure they were tight,. put everything back as it was and replaced the fuse again. Now everything is back to normal, for now! I hate these kinds of problems, intermittent stuff sucks. We will see!
I also checkes the tail light sockets and wiring as well as the post interior lights too!


Thanks for the suggestions!
John B.
Click to expand...
 
sounds like an intermitting short, like a bare wire touching ground every once in awhile, happened to me before
 
I have both pages of the 67 wiring in a pdf file and a picture file if needed.
 
Yea so it's back Dammit! I looked at the wiring from the tail lights all the way to the kick panel on the drivers side. Blows in just a few now! I know it's over 25 amps now because all I had left was a 25 amp fuse and it blew that! I hate this crap. I do have a 67 shop manuel on CD but the quality is poor, hard to read cause of the bleed through! I looked in the fuse box again and see nothing wrong,nothing out of place or a bare wire. Nothing!

Could a bulb cause this? I mean pulling 25 + amps ain't supposed to happen!

When the fuse is new everything works correct, when it blows I have no pillar interior lights, the map light under the pass side dash comes on (safty feature) and stays on until I disconnect the battery, and I noticed last night my instrument panel goes dark, Head light Switch? although just a couple years old?

Help!!

John B.
 
A bulb could be shorted. You need to go back to your other thread and download the FSM posted there.

One thing that will help save fuses is to "rig" a flasher and big heavy bulb and put them in place of the fuse. KD tools I think actually used to make a test rig like this.

Get yourself a tail/ stop socket, and put a heavy duty bulb in. Twist the two wires together out of the socket. Solder or hose clamp a wire connection onto the ground shell of the socket. So you can hook it up like so:

(One clip of the fuse holder) ---hooks to--- (One wire from the flasher) ---(Other wire from flasher) ---hooks to--- (two twisted wires from socket) ---- (ground shell of socket) ---hooks to--- (second clip from fuse holder)

Use long enough wire to hook this up so you can get the lamp up into the window area, so if you are back in the trunk or back seat, you can see it easily

Now you have a "blow proof" fuse that will just sit there and flash the lamp if it shorts


You need to determine what the major disconnect points are for parts of the harness. for example, there is traditionally a separation point in the left kick panel where the rear harness heads into the sillplate and back towards the trunk.

So you could disconnect that connector and separate that part of the harness.

Another thing to try is disconnect the connector going up to the column switch, to see if the signal switch has a short to ground.

Another way you can do the above is to just use a big bulb, no flasher. The bulb will light when the short is in place. Now go around and shut off/ remove all loads, remove all tail lamp bulbs, the dome light, etc, and if there is no short, the bulb should be OUT. Now you can do "wiggle tests" etc to find the short.

(Wiggle the switch as well as the harness)
 
A dead short is supposed to burn something. Once you install a fuse that wont blow the wire , etc.. begins to burn. That will lead you to the problem. Just kidding. I remember when people would wrap blown fuses in foil ( chewing gum wrapper ).
Try this ... remove the dome lamp bulb. Put a test light at the fuse box even across a blow fuse. When the test light goes off the short is gone. Saves on fuses anyway.
I'm going to guess what your problem is. The wire insulation shrinks with age and heat exposing bare wire that creates short circuits.
 
More digging! I am not ready to claim victory just yet, but I did find something. If this turns out to be true then I have had the problem in my hand several times! Take a look at the picture, see the retaining ring on the interior post lamb bezel, notice it has sprung loose and would touch the lamp socket and grond it to the body! Humm! Directly associated with the circuit in question! I will know for certain after some more time.

John B.
 

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Yep, Those lamps in the rear of fastbacks a notorious for breaking.
 
I've worked on cars, electronics, and HVAC. ANY technician can tell you that the worst problems are the INTERMITTENT problems.
 
Seems to be holding thus far! Went on a cruise and all is well. I repaired the bezel and installed it. Should not be a problem anymore!

I as well have been in the electronics, electro/mechanics field for 27 years and you are correct those pesky intermittent deals are the worst!

I hope that this adventure might help some one else someday!


John B. =D>
 
Seems the interior post lamp bezel was it, dang it. So simple yet frustrating!! been driving her all day and no issues, I am ready for the Lonestar Hot Rod Round up in a couple of weeks!

Thanks to all!

John B.
 
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