260z no start once hot ..all electrical gone when hot

[theatriks]

OK guys I have a strange issue ....i have a late year 1974 datsun 260z ....its got new wires cap rotor...new starter and battery...and new coil.

 

 

When it has been sitting and cool i can start the car right up......

 

Once i start driving it and it heats up after i shut it off .....it doesnt start ...as a matter of fact i loose all electrical power not even the door chime works !!!!...no click ...nothing!!

 

After the car gets a chance to cool down ....it will start right up!!!!

 

 

Has anybody experienced this strange problem im having .

 

Thanks

 

Rob

 

[banzai510(hainz)]

Was soemthing wrong with the old coil? Feel if gets hot.

Put it back in see what happens.

 

But to me if not nothing I would ck the batter connections  Battery post corrosion ,crack batt cable lead ring, and the fusable link where the batter hooks up.

 

Does lights work when this happens? Yes then the batt connection most likley good.

Ignition light ON when you cycle key off then back to ON or is it off.?  Maybe key switch going bad? big guess on my part Im not a Z expert on this site

[banzai510(hainz)]

ON my 521 thid is a fuse box power issue issue comming from the battery

[theatriks]

-battery cables are new i should add.....i am now starting to think it might be a bad ground ....because when its cold everything works its once its heated up that i get nothing and since im not even getting a door chime it has to be an electrical wire or corrosive connection....BUT where ?....im hoping somebody seeing this thread has run into the exact same problem.....im no good at finding electrical issues ...

[Elkie]

I would check at the fuse box and see if its getting power there, if it isn't chase it back to the battery, otherwise you will follow it from the fuse box out.

[datzenmike]

Some things have power to them at all times regardless of the ignition key, like headlights, horn, clock, brake lights. If these work then the battery and ground is probably OK. Do headlights work yes or no.

 

Stuff that need the ignition on, like the chime, wiper, heater fan, radio have their own fusible link and feed to the ignition switch and then to the fuse box side that has these items. The ignition turns these on. As said above check the fuse box for power. (or lack of)  I can see the chime not working from a bad ground but not multiple items as most have their own ground.

 

The S30 is notorious for bad fusible links. Many people replace them with regular large caliber fuses.

[theatriks]

Thanks for the replys guys!!!!! I am going to try to figure it out this weekend!!

[afbrian13]

I had the same thing on an old bronco. Ended up being a bad ground. Cleans all ground connections, you said you had new cables, check those fusible links-while moving them around. Ohm out everything cold, then when it gets hot and won't work. I'm sure you'll find one gets really high ohm reading when hot (meaning it can't carry the load)

[theatriks]

Ok so it turns out it was a fuse in my fusible link box this whole time ....

 

 

 

now to figure out whats melting this guy....ive started by buying a new fuse holder and fuse and see how quickly it happens again ....im wondering if its the new starter i put in ...because thats the only change ive made along with a new coil .

[datzenmike]

Not factory fuses, so someone had done some modifying. Those are 30amp? that's a large draw to blow them. Rather than blowing fuses get a test lamp and connect one end to positive battery post and the other to the grounded side of the fuse. Start unplugging the circuits on that fuse. When the light goes out you've found the cause.

[theatriks]

30 amp and the metal piece in the middle didnt snap just the case melted ...but that is probably the same thing....electrical is the worst for me ...i am a more nuts and bolts type guy...but im learing and trying my best .

 

I will try what you suggested ....just to clarify that fuse was in a fuse holder plugged into where the two fusible links are under the hood by the passenger side shock tower.