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Datsun 521 fuse box question


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B = + coil goes to blk/wht wire which is 12volt Key switch.

C = -coil

 

 

what is that BLK/Grn wire doing??????????

the tab on the dist is just a ground lug to ground to the chassis of the vehicle.

 

I would ck what the blk grn wire does. It might not be needed. It moight have went to the old poin condesor on side of the fender. I dont use it myself.

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Your speaking Ebonics.

You talking about the electric choke wire tab on carb.

I guess carb would have 12volt with key ON. Thats how mine works.

Since you got a 1970 your truck did not have a POWER wire for the carb. Some people get this off the +coil. I think it look tacky but works.

 

 

If you get a OHM meter and measure from the TAB to ground you should get close to a short as the Element in there is just a pc of wire that made to bend when heated up with 12volts . When it heats up it will pull on the carb butterfly lever thus open it. then 12volt is gone it cools back to its normal position.

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Yes that a anti deaseling selinoid and the choke

 

I daisey chain the wire at the choke(round plastic part) to the seleniod.

 

means 2 wire at the Choke then route 1 off that to the seleniod so you dont have to run 2 complete sets of wire where ever they are comming from.

 

the part store shold have a piggy back brass connector and you could hook up at the choke then make a samll 1 or 2in wire to the selinoid. Done a little bit cleaner so you coul get rid of one wire.

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Did you say you hooked the (-) side of the coil to ground?

 

Well, it won't run that way. 

 

(+) on the coil goes to switched +12V, which also goes to ( B  ) on the matchbox.

 

(-) on the coil goes to © on the matchbox ONLY, unless you have a tach.  With no tach, that wire goes ONLY from the coil to the matchbox and NO WHERE ELSE.  Ground is provided through the matchbox and is switched on/off, just like points except done electronically.  If you have a tach the tach's trigger wire goes there too, but never, ever hook that to ground.  Fortunately it won't hurt anything, it just won't run.  In fact, grounding the (-) post on the coil is how you shut off some engines.

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the coil and the tach and distributor are connected correctly, the truck starts and runs fine

my concerns are that the two connections on the carb are going straight to ground, nothing shorts but i dont like how it causes the switched fuse box side to go straight to ground

 

but the only problem im having is that the truck is not charging, new battery, new voltage regulator, and new alternator

 

could this be the problem: i got a 60 amp alt instead of the 35 stock one....

are the regulator different for the 60 amp and 35 amp? or do they share the same regulator?

please say yes they are different so i can replace it and get back on the road and sleep good tonight

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Dafuq did I just read?

With the way you explained having those wires hooked up, it shouldn't run.

 

You can install a 60amp, should be fine. however, what did you get the 60amp for???  Is it for a 720, ZX or what?  Or was it a more expensive replacement meant for that 70 521.  Newer alts are internally regulated vs externally like older rigs

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Regulators aren't different.  They're the same.  What is the alternator from?  As izzo said, if it's too new (1978 or newer) it's internally regulated which means there's wiring alterations needed AND the regulator isn't used.  If it's a 240Z/260Z/280Z or 610/710/810 alt (through '77), it'll be externally regulated.

 

Now, the pic you have of the alternator looks like a stock 35A alternator, with the FN marked T-plug.  That's the correct alternator for use with an external regulator.  If it has an LS marked T plug, it is NOT the right alternator (internally regulated) which means some wiring mods have to be done.

 

 

Now, for the idle cutoff solenoid.  You plug it in, everything goes dark and the fuses blow due to a dead short, or plugging it in makes your ohmmeter read zero?  The internal coil in the solenoid doesn't have much static resistance, though it should have SOME.  A few ohms.  Once energized it has a lot more impedance.

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I believe one of the contacts on the T connector should have 12volts with the key ON. this will energize the alternator windings. Ck that.

 

the choke and seleniod is fine I bet AS POST #31 i WROTE(YOU READ IT?). its a coil and a wire thatS IT, and will read close to ground with a OHM meter as one side is grounded. The resisitance is just so low you think its SHORT ON YOUR cHEAP CHINESE mULTIMETER.

 

 

if this all worked before tthen this happen after the wire bundle swap then its got to be a loose wire soemwhere.

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ive been using a pretty good voltage meter, so on the fuse box the switch side goes straight to ground, and when i unplug the carb connection it doesnt go straight to ground, i think its been shorting thru carburator

 

im gonna replace regulator again and see how it runs without connections to carb

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To be sure that you are not in fact reading reverse current through a diode, take 2 measurements.  Red lead to object, Black lead to ground, then flip.  Black to object, Red to ground.  When you switch the meter to Ohm scale you are actually applying the Negative pole of the internal battery to the Red lead and the Positive pole of the internal battery to the Black lead.  Just think.  You are measuring microamps of current flowing into the red terminal.  If the internal battery Positive was connected to the red terminal your meter current would flow backwards.

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thanks for all the info fellas, i got another voltage regulator (new), its started charging pretty good, my gas guage wasnt working tho....

anyhow when i started revving it high the regulator went out, i put another regulator i had laying around and when i revved it high that one went out too...

im gonna warranty the new regulator and if that one goes out too im gonna sock myself in the face and go internal regulated alternator

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the 2 switched fuses are going straight to ground again, alternator tested positive, now ill start to inspect harness (which was not in good condition)

heres a picture of the inconvenience of wire tucking

poop002_zps39a586e8.jpg

 

 

Carlos, buddy, this has all kinds of bad written all over it. I didn't know this is how you did it.

 

Some pointers:

 

-Extend or make plug in extension for all the relays, etc. Put those in the cab or somewhere else safe.

-You need to protect the wires from debree being picked by the tires. A lot of people use plastic wire loom, I use 1-1/4" liquid tite whenever I do this. If you don't change this, you are asking for possible damage that may make some serious work for you or possibly wind up with a big rubble pile on the side of the street.

 

 

Once I get my garage cleaned up, your more than welcome to pop over for some help or whatever. I live right down from Jimmy's.

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running the relays inside is a good idea, i didnt think about that...im gonna use it like that for a little bit but im deffinately gonna make it look alot better, all that was done in a bit of a hurry cause i didnt wanna miss shokuji j-tin........thanks for the offer on the garage but i think next week im getting a fat carport in the back, ill install some lights so i can finally work at night and have something to do on my truck after work, but i might still give you a visit to learn how to use that fender roller B)

Carlos, buddy, this has all kinds of bad written all over it. I didn't know this is how you did it.

 

Some pointers:

 

-Extend or make plug in extension for all the relays, etc. Put those in the cab or somewhere else safe.

-You need to protect the wires from debree being picked by the tires. A lot of people use plastic wire loom, I use 1-1/4" liquid tite whenever I do this. If you don't change this, you are asking for possible damage that may make some serious work for you or possibly wind up with a big rubble pile on the side of the street.

 

 

Once I get my garage cleaned up, your more than welcome to pop over for some help or whatever. I live right down from Jimmy's.

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Your poping regulators for a reason.

When I pop one its usually the power or ground cable was loose during a motor swap.

So I assume its along that lines.

I get good results of the solid state VRs and look like one in the photo.

 

when you turn the key ON cirtain circuts will go to ground to complete the circut. Kinda like the starter motor. Its grounded.

 

If you really think the carb is grounded as it SHOULD BE it would POP a fuse.If a tru SHORT!!!!

However unplug the choke and selinoid and start the truck. see if regulator pops which I think it will. But no idle selenoid truck wont idle and you have to pump the gas to keep it running.

 

most 521s and 510s there was a blk ground wire by the volt reg . That still shorting to chassis???Ck with meter. I see it on the photo but maybe to much paint?

 

 

putting a External alternater isnt going to fix it right.

 

wheres the battery on this.?????

I have the neg cable going to the head behind the fuel pump. Maybe route another wire back to the chassis or temp wire and try that

 

 

Carlos, buddy, this has all kinds of bad written all over it.

 

water& (mostly condensation) will say inside the tape and plastic covering even longger to dry out once wet

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