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OUCH!!! 521 fuse block options.


flatcat19

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You need four jumpers for a 521.  On the previous page, the jumpers are installed on the battery side of the fuse box to make four always hot fuses, and two switched hot fuses.  Earlier 521 trucks were wired for three always hot fuses, and three switched hot fuses.

it looks like you had a four always hot fusebox on your 521.  Look carefully at the Blue Sea fuse box I put in.  On the battery side, you can see the jumpers, except between the second and third fuse, from the left side of the picture.

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IMG_20160422_213253331_zpsksrriohp.jpg

 

 

This is what the current/broken box looked like.

 

I know this can't be the correct fuse ratings.

What should they be?

 

Notice-lower left-common/linked circuit-nothing was connected to the far left, so I did not jump those posts together while modding the new box.

 

What am I missing?

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This is what the current/broken box looked like.

 

I know this can't be the correct fuse ratings.

What should they be?

 

Notice-lower left-common/linked circuit-nothing was connected to the far left, so I did not jump those posts together while modding the new box.

 

What am I missing?

I would think you have to jump those far two circuits together. If they were bussed on the old one, power was going through both with the one hook up.

 

What is the build date on your truck?

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Your diagram is right, except it is b/w wire runs from ign switch to fuse block, block to coil. Yours has both wires running to the right one, it should have one running to each.

IMG_20160128_214831_zpsg0knxfrg.jpg

IMG_20160425_080216_zpss9989asf.jpg

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There should be a white wire, with a blue stripe, and a ring terminal, connected to one of the two terminals, that have the pair of black wires, with a white stripe.  This wire sends switched ignition power to the stock external voltage regulator, and the voltage regulator in turn sends this power to the field coil of the alternator, so the alternator will charge.   This is for a externally regulated alternator, a alternator with the "F" and "N" marking on the small terminals.

If you switch to an internally regulated alternator, this wire is no longer used.  For reference, an internally regulated alternator has "S" and "L" markings by the small terminals.

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I do have an IR alt.

 

Never had that white wire you speak of though.

 

 

Everything functions as poorly as it had prior to. Lol.

 

Tested it all. But not for long.

Disassembled stuff chasing an overheating issue.

 

Rad is out getting boiled. New water pump. Flushing block and heater core tomorrow night.

 

Follow along here...http://community.ratsun.net/topic/66135-lets-try-this-again-flatcats-521/

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Before putting the radiator back in, do this to really flush out the engine.  Remove the thermostat, put the T-stat cover back on.

Put the lower and upper radiator hoses back on the engine, point the upper one over the core support.

There is a plug down by the starter, it has a 14MM head, remove it.  You will need a six point socket.

Get a compressed air hose, with a nozzle on it.  Put a garden hose in the lower radiator hose, fill the block, and let the water run out the top radiator hose.

When the water runs clear, blow compressed air into the hole the plug by the starter was in.  This will dislodge a lot of crud in the block.  Let the block fill again, blow compressed air into the drain plug hole again, repeat until blowing air into the drain hole, with the block filled with water, does not remove any more crud.

Flush the heater hoses, both ways. 

Put the plug back in, put the radiator back in, refill the radiator with 50/50 antifreeze, and distilled water.  best price on antifreeze I have found is at Walmart, even the mini Walmarts have it.  Distilled water is also at Walmart.

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