Overcharging & Killing fuseabel link

[ole silverado]

Hi everybody... My 1982 Silverado has a well working and new Battery and a new Alternator. Still the fuse able link (fuse) by the firewall connector keeps blowing from time to time. When it blows the volt gauge on the dash shows 18 volts just before it goes... Between these times it all works fine. Can it be "something" that makes the alternator deliver too much voltage ?  and makes the fuse brake.? It is a "by pass fuse" instead of the old fuse-wire . I have a 30 A fuse in it.

[bake74]

     First off welcome to the site.
     Are you saying that you have a 2 prong 30 amp fuse or a glass 30 amp fuse in place instead of the fuse-able link ?

[bd]

Remove the 30-amp fuse and install a correctly sized fusible link.  See How to make a Fusible Link.

Fusible links are used instead of fuses for a reason - fuses don't offer the overload characteristics provided by fusible links, not to mention the fact that 30 amps is way too small for primary bus protection.

Alternator flare is likely caused by poor connections or a faulty regulator.  Go through and verify all vehicle grounds: battery-to-engine, battery-to-frame, battery-to-radiator support, right rear cylinder head-to-cab, etc.  Pay particular attention to the alternator case ground through its mounting.

[ole silverado]

For some reason the inline fuse wire was burns, and when I got the truck, it was installed this " bypass wire" with a fuse-box, (not glass fuse) . I got a new alternator, but the same problem with overcharging came again with the new one. It comes suddenly and always after a startup, not when driving the truck. Last time the windshield wiper came on, whit out a reason. I did not turn it on...!  Could it be something that fools the regulator to give too much power..?

[bd]

Post pics showing the "bypass wire" and "fuse box with fuse," the alternator wire connections and mounting, and the battery-to-engine ground.  If the truck has intermittent w/wipers, pulsing of the wipers maybe caused by the charging system when it spikes the voltage.

...Could it be something that fools the regulator to give too much power..?

I'll repeat...

Alternator flare is likely caused by poor connections or a faulty regulator.  Go through and verify all vehicle grounds: battery-to-engine, battery-to-frame, battery-to-radiator support, right rear cylinder head-to-cab, etc.  Pay particular attention to the alternator case ground through its mounting.

Checking and cleaning all of the grounds is a good starting point, since the entire electrical system functions with reference to ground.

[ole silverado]

Here is the so-called by pass fuse Box. We can see the end from the old fuse wire. The tape is just for protection. Inside the red Box there is a 30 amp flat fuse.

[ole silverado]

The new alternator with battery ground on top...

[ole silverado]

Another pic of the by pass fuse box...

[ole silverado]

Battery to front support grounds...

[ole silverado]

Engine compartment... You can see the power cut-off on the battery ground side...

[ole silverado]

My 1982 Silverado imported to Norway from Hickory, North Carolina.

[bd]

Sharp looking truck!

Carefully inspect the charging system and cab harnesses for chafing or melting to ground.  Pay particular attention to all the harnesses around the engine and where they approach the exhaust.  Your problem may stem from a cable arcing to ground.

Temporarily remove the battery disconnect and attach the ground cables directly to battery negative.  Replace the "fuse" with a six-inch long, 16-gauge fusible link as previously posted.  Crimp, solder and heat shrink the fusible link terminal connections and wire splice.