1986 Nissan 720 king cab automatic transmission

[builte]

Recently my 720 has been dying while driving doesn't matter where or when it's just random I have no idea what I'm doing and I need help I've checked for vacuum leaks and there are non it has gas in it and the alternator is good any ideas  💡 would be greatly appreciated 🤠

[datzenmike]

 

Here's more info...

6 hours ago, builte said:

My Nissan 720 started dieing at stop lights and would have to let it sit a few minutes before starting again to take off when I got home I parked it for a day went back out and tryd starting it the battery was dead so I charged drove it around the block a few times with no problems and parked it again after about 45 minutes I tried starting it again it would not start only sound it made was the humming of what I assume was the fuel pump I need some suggestions on what to do anything helps thank you 😊

 

Batteries don't die just from sitting over night. As this suspiciously happened at the same time, it's likely a symptom. Just to be sure, clean the battery posts and clamps.

 

Charge the battery over night and in the morning start the engine and briefly, and I mean just for a few seconds, disconnect one of the battery cables. If the engine is running and the alternator is charging then it should run without the battery.

 

Disconnect battery and engine quits: Charging system not working.

1/ Could be alternator.

2/ Could be the fusible link has failed not letting the alternator charge the battery.

 

If the interior light, horn, clock, or brake lights are working then the fusible link is OK. 

 

Is the red charge light on the dash on?

 

 

 

 

[builte]

I have it on charge now and yes the battery light is on I'm gonna go give it a try in the morning and by fusible links you mean the plugs on the positive battery wire right?

[datzenmike]

Could still be the alternator but you don't want to buy a replacement to find out later that it was a bad fusible link.

 

IF it's the fusible link then it's the Black one. It may look crispy if burned out. The wire inside may be broken but the black coating intact. Be sure the connections are clean and secure. Disconnect one end and check for continuity with a meter or make a small jumper wire around it but just for testing. Only replace with special fusible link wire.

 

 

[builte]

Ok so I went out this morning and tried to give it a start it turned over one time and then nothing all the lights work and the battery reads good I gotta get to work at the moment but I will check the fusible links when I get home. Another thing that I should have mentioned earlier but is only occurring to me now is that my dad put a new battery in backwards for maybe 40 seconds a few days earlier.

[builte]

Another quick update it will jump start I got it running just now and popped the positive terminal It did still run although it ran rough for the few seconds the the terminal was off 

[datzenmike]

As long as the key was off shouldn't hurt anything. Battery posts are different sizes to prevent mixing then up.

 

The alternator may be kicking out some slight charge. Measure across the battery with it idling. Should be just above 14 volts.

[builte]

right now it is measuring 13.8

[datzenmike]

Try with head lights and heater on. To keep a 12.6 volt battery charged it needs almost 2v more to 'push' the charge into it. It has to be able to do this under load when driving and it has to do this as soon as possible.

 

 

[builte]

Ok right now the battery is holding 12.13 while running but as I was testing it the alternator started throwing sparks and smoking I do not understand as it tested good before can I assume this was all coincidental and replace the alternator?