Bad Alternator maybe?

[79datsun620]

1979 620, The first day it started givin me problems was tuesday while I was driving the dash lights were giting deam and my blinkers were barely blinking and then when I parked it I tried starting it and the battery was dead. I rolled it off and got it home and then the next morning I got in it to go to work and the head lights were so deam I could'nt see so I drove my other truck.The alternator light never came on though so i'm not sure,I put another alt. on it that I had of my 280Z and now the alt. light comes on, so is there something besides the alt. and batt. it could be?

thanks David

[banzai510(hainz)]

use a volt meter and what was the out put????????

 

when you put the 280z alternator in Is it a external or Internal volt reg. I dont the cut off year on the 280z if they had ext/internal volt regs.

 

Did you hook up the T connecter whn you put the 280z alt On there

 

 

take orginal alt to NAPA and they can do a load test on the alternator.

[79datsun620]

I dont know what the volt reg looks like but there is a black plastic cover on the back of the alt. I think I will take it and get the other one tested.thanks hainz

[banzai510(hainz)]

take the orginal alternator from the 620truck and have it cked at NAPA and make sure they put a load on there. If they dont it dtill can read 14volt when the y put it on a tester.

 

Your Z car alternator might be a external regulated as it list on Rockauto.com.As it lists 76 and 77 280z as EXTERNAL volt regs. looks like 78 was the transition year for the internal volt regs.

 

the black screen is usually a externat type alternator But not alwasy as I have the newer external type ones that dont have the black screen also.

[datzenmike]

Your '79 will have the internally regulated alternator with a Black wire to ground, White/Red stripe wire that goes to the Green fusible link at the positive battery terminal and a White two prong connector with Yellow and White/Red stripe wires on it.

 

Check all connections are clean and tight.

Check both battery terminals are clean and tight.

Check the negative battery caable is clean and tightly bolted to the head behind the fuel pump.

Check that the positive cable is clean and tight where it connects to the starter terminal.

Make sure that the Green fusible link isn't blown. The insulation may appear melted, a sure sign that it may be blown, or not. But check that it is conducting or no power from the alternator will be able to get in to charge the battery.

Maybe slip another battery in there and see if it stays charged.