# Made a stupid mistake with a fusible link...



## robzero (Nov 12, 2006)

In trying to diagnose an ongoing electrical problem, I was certain the reasons for my trouble was because of a fusible link (the link located just at the positive battery terminal) being corroded. I played around with this link and decided to disconnect it while the engine was running to see if it even served any kind of purpose in its corroded state.

Big mistake.

It looked like most of the electronics went crazy with all of my lights inside and out getting very bright. I made a mad dash for the ignition and turned off the engine.

So now I don't exactly know what I've just done. The clock on the dash doesn't work now, the radio is out, and the little 10A fuse for the dome light won't stop blowing out. No idea where to begin on fixing this.


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## HATEnFATE (Dec 24, 2002)

what happens when you re-install the fuse?

It sounds like when you pulled the fuse out you caused a short between the fuse poles in the circut. That shouldn't have caused that problem unless there was an underlying condition to begin with. 

Ther clock, radio and dome light are all on the same circut so it sounds like you've definalty got a short somewhere in that area. Do your running lights function? do your ineterior dash lights come on? If not then you might have fried your rheostat(dimmer switch). 

If it's not something simple then what your going to have to do it trace your wiring back with a multi-meter and get a wiring diagram of the car. You'll need to know what wire does what and what wire is supposed to be at what voltage. When you get to one not doing what it's supposed to do, then you've found your culprit.


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## terry lingle (Jan 7, 2006)

or perhaps the chrome muffler bearings spun backwards 
Since the lights got very bright the voltage must have gone up. For that to happen the alternator feedback sensing stayed at battery voltage but the disconected link opened the chargeing to the battery and allowed the circuit voltage to rise. 

The loads normally fed from the battery by that fuseable link were powered only by the alternator. A tiny drop in battery voltage would turn the alternator on to bring the battery voltage up. The open link prevents the battery voltage from rising to normal. The output voltage of the alternator went way up and all loads connected to that circuit were exposed to that high voltage.

In a word ouch,

At this point it is easy Reconnect the link start the car. check that the alternator now works properly as it may have been damaged. if it is ok try each electrical circuit in the car.
Make a list of what is not working. Get prices on car specific replacements and determine if tthe cost of repair is justified. 
Aftermarket electronics that were fried do not enter into this as they will need replacement or repair even if you replace the car good luck with it 
Terry


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## robzero (Nov 12, 2006)

alright, I checked everything and when the car is started the only things that don't work are still the room light, dash-clock and radio. I noticed that the Room Lamp [10A] and Electronics(IG) [10A] fuses will not stop blowing up when replaced. The alternator still runs fine.

Are you saying that the devices(clock etc..) themselves are broken? I thought that the fuses were suppose to prevent that from happening by blowing out.


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## ConKBot of Doom (Jul 24, 2006)

robzero said:


> alright, I checked everything and when the car is started the only things that don't work are still the room light, dash-clock and radio. I noticed that the Room Lamp [10A] and Electronics(IG) [10A] fuses will not stop blowing up when replaced. The alternator still runs fine.
> 
> Are you saying that the devices(clock etc..) themselves are broken? I thought that the fuses were suppose to prevent that from happening by blowing out.


Start disconnecting things and see what the cause of the short is... Pull the bulb from the dome light, check with a multimeter and see if it is still good(dont put it back yet). Pull the radio and see if you still blow fuses. If you do, open up the dash and disconnect the clock, and see if it is still shorting.

With all 3 pulled and it still shorting. Then you will have to try and find a wiring short... but I would expect it to be the radio or clock, and not a wiring short.


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## terry lingle (Jan 7, 2006)

fuses are not in the circuit to protect the load from damage caused by electrical malfunctions or your own mistakes . they are there to protect the wiring harness and the rest of the car from a fire caused by a failure in the circuit beyond the fuse . The voltage on that circuit could have gone as high as 150 volts but likely did not get above 20 -30 volts. That is enough to cause short circuits in electronic devices and to destroy them . Then the destroyed device takes out the fuse . As the last poster said separate the things on the circuit then re attach them until you determine which device is faulty It is not likely lightbulbs or wiring but it is probably the radio . Sounds like you were pretty lucky it did not get the ecu or ignition . Terry


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## robzero (Nov 12, 2006)

Update: Turns out it was the passive seatbelt computer in the trunk that shorted out on me. Unplugging it stopped both fuses (Room Lamp & Electronics IG) from blowing out. The clock also returned.

Just going to need to find a seatbelt computer on ebay or something..

Thanks for the help everyone.


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