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521 no charge


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My 521 is not charging again.Happen last night so no time to look at it.

The 1st fuse on the left keeps popping. THis time replace fuse turn key ON but no ignition light.

Alt is only 3/4 months old.

 

Fuck I cant get more than 6 months before this thing breaks again.

Last fix was a new alter. prvios fix was reseat the instrument panel.

 

aJust wonder if its the alternator again.

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Are you running an external regulator alternator, or an internal regulated alternator?

 

An external regulated alternator needs power from the ignition switch to the switched hot fuses on the fuse box to supply power to the regulator, to make the regulator supply power to the field winding (rotor) in the alternator for the alternator to work.

 

An internal regulated alternator needs power coming through the charge light for it to work.

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external  reg that is fairly new.

I thought I had this figured out but maybe soemthing is causing it to run the fuse hotter.

 

Ignition light does not turn on when key to ON. I assume the fuse pops right then. I had the t connector removed. still the fuse popped.It was late when this happen and said fuck it.  521 have most proplems by the fuse box. Tired of this.

 

 

I assume the charge light is OK cause then the fuse woulnt pop. as a open light would not conduct current thru the circut

 

So Daniel

So your saying the ext reg could be shorted and poping the fuse also?

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Are you running an external regulator alternator, or an internal regulated alternator?

 

An external regulated alternator needs power from the ignition switch to the switched hot fuses on the fuse box to supply power to the regulator, to make the regulator supply power to the field winding (rotor) in the alternator for the alternator to work.

 

An internal regulated alternator needs power coming through the charge light for it to work.

This confuses me as it is not how I wired my internally regulated alternator in my 521 work truck, the bottom of the "T" goes to the dash light while the top of the "T" goes to keyed power and my ignition light works properly.

If this is not how it is wired then can you explain what both the "T" plug connections are for, if the light and exciter wire are the same wire, what is the other connection for?

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Easy question first, that is Wayno's question.  But there is useful stuff for Banzi here too.

On a internally regulated alternator, there are two connections made with the "T" plug.  "L" and "S".

In my mind, I think of the "L" for light, and the "S" for sense.  The alternator uses the current from the charge light to provide an initial current to magnetize the alternator rotor.  Once the alternator generates it's own current, then alternator can then use part of the current it is making to magnetize the rotor.  It also applies the voltage it is making to the "L" connection on the alternator, and since the alternator is supplying voltage on one wire of the charge light, and the ignition switch is supplying voltage to the other wire on the charge light, the light goes off.

 

An internally regulated alternator uses the "S" wire to measure the voltage in the electrical system.   This is because the internally regulated alternator need to know what the voltage at the battery is, not what the voltage at the alternator is.

 

Banzi, Ignition power is supplied to the instrument panel.  Ignition power is applied to the instrument voltage regulator on the back of the instrument panel, to the oil light, and the "IGN" (really a charge light).  The oil light is grounded by the oil pressure switch, with no oil pressure.  The "IGN" light is grounded by a relay inside the alternator voltage regulator, if the alternator is not making electricity.  This is based on an OEM 1790 Nissan (Datsun) mechanical voltage regulator.  Once the alternator makes electricity, the ground is just lifted on the "IGN" so it goes off.

 

You mentioned in your first post you did some work on the instrument panel.  I would see if that is the root cause of blowing the instrument panel fuse.

 

 

this thread may also be a help.

http://community.ratsun.net/topic/30917-combination-meter-521/?hl=%2Bcombo+%2Bmeter

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Daniel. MY frist fix a long time ago was reseat the intrument panel. Was blowing fuses. NO ignition light

 

last one which was the same fix as DP on here was swapping out the Alt. But on this one I would get charge light then truck runs and bam the ignition light come on.  It also would pop the Solid state volt reg. So I went to a mechanical type.

 

I run a diaode Voltmeter from my cig lighter so thats how I know im not charging. otherwise most people wont catch this .

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FIXED

 

I removed the T connector and the pos out put wire.

 

I put a new fuse in. While my hand thru the Wing Window I looked at the fuse and turned Key ON. IGN light was ON.

I then put the pos wire back on the Alt and turned Key ON . IGN light was on.

Started truck was fine.

 

seems to be just a reseat of the fuse block or the Pos output screwd tite. But it was tite bfore all this happen.

Lucky fix

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