dead pickup

[bertmobile]

I've got a '79 Datsun 620 pickup. Driving last week and the fuseable link fried (just like it's supposed to). Any ideas if it is most likely an alternator problem or maybe a voltage regulator problem? It's got 64,000 original miles.

Any suggestions would be most apprecitated!

Thanks!

[bertmobile]

I forgot to mention that the truck is totally dead. No lights, horn -nothing. Battery is still charged however.

Thanks!

[denveratsun]

:blink: Did you replace the fuseable link? :blink:

[Bleach]

That year of truck would have an internal voltage regulator in the alternator. It could be a possibility for the fusible link going out.

Other causes could be a power wire somewhere grounding out causing a major load on that circuit.

 

Have you replaced the fusible link or put a small wire on it just to test and see if power returns to the rest of the harness?

[banzai510(hainz)]

I would ohm out the output post amd measure it to case of the alternator. If a straight short I say thats the proplem. I mean like less than a few ohm hopefully. A diaode shorted out.

Your alternator the reg is in side as its a internal regulator type.

 

 

This is what I would do.

disconnect the output wire on the altarnator.(make sure not to short out to ground)

Replace the fusable link or get a smaller gauge wire and put it back.

 

disconnet the minus side of battery and put a test light inbetween the minus battery post and the cable you just took off. Get soemone/you hook the alternator output wire back up. If test light comes on a I say there is a power draw(make sure lights and door light ,dome lights are off.)

But usually this would drain the battery unless this was a instant failure and saved the battery.

 

If thats too hard for you I say get another alternator.

 

 

I would clean the contacts and fuses.

 

I think 79s had a eleltric fuel pump also. maybe clean the ground on that also.

 

clean battery cable and the cable ground.

 

If one has H4 lights and not using a relay it can load up the fusable link also.

 

 

this is a EZ fix. Unless you added something and didnt tell us

 

 

besides the fusable link did a fuse blow and IF what circut was that?

[bertmobile]

regarding the fusable link, I replaced it w/ a wire that has a fuse installed in the middle. I hooked it up w/ a 20 amp fuse and it blew so at least I know the fuseable link will do it's job properly once I find the problem.

Thanks!

[datzenmike]

The '79 used a Green fusible link between battery and the rest of the truck including the alt. The Green link is rated at 40 amp. A fuse is not as good as the fusible link that can handle a short duration overload without blowing.

[bertmobile]

good to know! Do you know what guage it would be? I found a fuseable link on line for $6 and shipping was $10 so I thought I'd give my method a try but sounds like I should replace that w/ an OEM (or similar) replacement part.

Thanks!