620 pickup alternator problems

[Austinmorris96]

So I traded for a 620 pickup a couple days back and it needed a new batterie so I replaced it but did an old school taking the negative terminal off test to see if the car would run with it off to see if the alternator was good or bad well it died so I tested the alternator and it tested positive so I started looking at the wiring and it's pretty jankity, I saw that there was no ground going from the block to the frame so I'm wondering if that would have anything to do with alternator problems. Thanks

[datzenmike]

There has to be a good ground from either the battery or from the block (which is grounded) to the body sheet metal. This is always a good idea but not critical to alternator operation. There should be one on or near the battery tray or just make one.

 

The voltage regulator is built into your alternator so it possibly may be bad, but first be sure that the two wire plastic plug in snug in the back of the alternator. There will be an insulated terminal with a large White/Red stripe wire (this is the power output) and a large Black wire for (ground). Last are the brushes inside the alternator. You used to be able to buy them for $10 and just replace them yourself. It isn't a particularly hard job.

 

You can remove and have tested but you know it isn't working right anyway, and a replacement alternator these days are nothing short of absolute crap. Half are 'bad in the box'.... just read any other charge problem posts where an alternator has been swapped. Many are on their second or third free replacement'. Try to get your original Nissan alternator going first. Second would be a used alternator from a wrecking yard, but it has to be from a '78 or '79 as these were the only years that have the internal regulator in them.

 

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