620 electrical problem

[South califas]

wut up havnt been here in a while i dnt knw if this is the right place to start this topic but i need some help my 620 is having charging problems i keep burning out regulator and alternator why i thought it would be the stereo i had wich was after market alpine amp of 700 wats so i took the stereo out but now it still burnt out i noticed that when i hook up the new regulator and start the truck it runs fine but the regulators resistor smokes for about two min and stops runs fine for a couple days but alternator quits charging and charge light comes on so my is has anyone ran in to this problem see i ts a shame when the mtr has a 150 miles on rebuilt and i cnt take out the sweetheart u knw please its got a lot of power but i need some hints of were to look at. : )

[Zeusimo]

Stock Alt Bearly Maxes Out At 30A

 

I Had A Problem Wheee Truck Would Run Fine

But Once You Turn Anything Electrical On...

It Would Never Idle

 

Bigger 60A Alt Fixed Everything

 

U Internally Or Externally Regulated?

[Boaty]

I'm not sure why the regulator would be smoking as you said, but I can second the above post.

 

Stock Datto alternators (well, even the 60A in some people's cases) really don't like a lot of electronic goodies. A lot of things have changed over the last 40 years.

Ask anybody that knows me, or has followed me along in the Datsun Community for the last 10 years. If it is an alternator, a starter, or a slave cylinder - I've probably gone through more than anybody else. Lol.

 

When considering upgrading your alternator, check out the Saturn alternator swap. I have gone through over 10 alternators, from stock to ZX to custom built, and the only one that has lived long enough to smile is the Saturn alternator. It's a 96amp I believe (I think there are actually 3 different amp ratings depending on year, but physically are the same - maybe different fans). It handled my stereo, my H4 lights, and even had to charge my Optima yellowtop a few times from near-dead, and I only burned up one because of belt tension.

 

I try to extend that suggestion to everybody that rolls a Datsun... it took forever but it just 'works', and they are simple to install. Plus, if it goes out, you can pull up to pretty much ANY parts store and they are likely to stock it (It's an A-mover).

 

Now, on the technical aspects of it... remember that general maintenance can and will save you lots of time, money, and effort in the future. Plus, everything is old and would likely enjoy a clean up/inspection anyways. And, it's a learning experience. Number one for any Datsun, check and inspect, and clean your fusebox. Probably has nothing to do with your situation, but it can help.

 

Check your grounds. Grounds can cause all sorts of issues - even ones that are inexplicable!

 

Check your battery cables, and check your battery. A bad battery (not necesarily old!) can eat up alternators really, really fast. They are there to keep up and maintain a charge, but aren't very adequate for charging a dead battery - especially low amperage alternators. It will work the altnernator full-duty and just eat it up from overheating.

 

Now in my 510, with the stock charging system & external voltage regulator, I would heat up and kill both pretty regularly. The voltage regulator usually just went out on me, causing me to over-volt the battery - which in turn spewed acid all over my engine bay, and destroyed my oil pressure line... which assist in the destruction of my L16. Smoke coming from anything is a bad thing.

 

Honestly, you're into a new engine.. it would be really beneficial to upgrade your alternator to an internally regulated one. Eliminates wiring, more amps, more reliability, and it fits in there nice and snug. Be nice and buy new cables, and enjoy a decent modernized charging system.

[datzenmike]

Did this charging system ever work normally???? What I'm asking is, was this fine and working good and suddenly it started having problems. Is it possible that a PO (previous owner) changed the wiring or alternator and screwed something up?

[pharouh]

Did this charging system ever work normally???? What I'm asking is, was this fine and working good and suddenly it started having problems. Is it possible that a PO (previous owner) changed the wiring or alternator and screwed something up?

 

 

Ding Ding Ding Ding! We have a winner!

 

I owned a 620 back when they were only a few years old. Never had a problem with the charging system. Almost dead stock truck. P.O.s do strange things sometimes

I have a 620 now where they ran a wire from the front turn signal up to the dashboard and fastened to the indicator light to let them know when the light was on.

Check and clean your grounds and connections.

[South califas]

well it started ever since i installed the stereo it over shot the alternato but now that it dnt have stereo sys it keeps burning these things up