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Topic: Electrical help please. (Read 844 times) previous topic - next topic

Electrical help please.

Why is my main fused charge wire blowing the 200 amp fuse?

This is the second time it has done it, in the past several weeks.

  FYI.......Ive done a 3g upgrade on it several yrs ago.  Replaced the regulator about 6 months ago.

Is the alternator doing it, or is it something else.  I usually notice it blows it, when starting the engine or just shortly after??????
Mike

Electrical help please.

Reply #1 –
Without knowing exactly how your conversion was done, I can only speculate, but it sounds as if you might have an intermittent short.  Check your wiring for frayed sections that may be rubbing against a source of chassis ground.  A hint to help you might be to look for scorch marks, where an arc might find ground. 200 amps is enough to weld with and should leave a scorch mark of some kind.  Good Luck!

Electrical help please.

Reply #2 –
hey mike,
do you have a clamp on meter that reads amps?

The battery is alternator load if its not ever getting fully charged.
The devices turned on by you are alternator loads as well.

all the loads added up shouldnt be blowing the fuse though unless your brand is not being correctly manufactured.

A lot of fuses being made as in the past 3 or so years have flipped the opposite direction of industrial fuses in that.......

industrial fuses - rated for approx 150% of thier name plate rating.
consumer fuses - Long and sweet, they assume you are going to not exceed 80% of the 200A design so they are making elements that are rated for 160A however having said that, the tolerance is now a + or - 20% and i would venture to say that for them to save money, they are leaning on the MINUS side of the tolerance so 160A x .8 = 128A.

swap brands
tell us if any connections look odd or corrosion appears under the insulation.

a clamp on meter will tell you what you are actually drawing.

remove the fuse (bypass it for a moment)
amp clamp the alternator charge wire
amp clamp the battery + cable
add these two together to sum your total demand.

on a separate test, amp clamp the battery during crank up with the coil spark plug wire undone and guesstimate the amperage demand during that event and report back.  This will allow you to crank longer so you can guess the reading without the inconvienience of the car actually starting.
could be something as simple as the brushes or bendix in the starter causing a huge inrush on the battery draining it beyond normal during start,, its possible that my end up being the issue.

Electrical help please.

Reply #3 –
I dont have amp meter.

The fuse I think should be a good brand "Kicker".  Ill check over the wiring when I get home.
Mike

Electrical help please.

Reply #4 –
"BUSS" or "Littlefuse" are good fuses

Kicker isnt a name industries list as options.