Datsun Sunny 1979 problem

[yobbo88]

Ok the Datsun forums are useless and i've been a part of this forum for ages so i'll ask you guys.

When driving this car the charge light has recently started coming but will go off as soon as i shift into top (4th) gear. At night with the headlights on the dash and headlights will visibly dim in any gear but 4th and the stereo plays up randomly shutting down etc.

What would be causing this?

Another problem, i'm not sure if its related, the starter motor wont engage when turning the key. You can hear the solenoid click out but will not turn the starter over. i've looked under the hood near the starter motor and there is a wire not connected to anything (looks like a ground wire), starting at the body of the car that seems like it would lead to the back of the starter motor but doesn't look like it was ever connected.

These 2 problems only started about 2 weeks ago.

I'm stumped guys.

EDIT:thanks for the move i wasnt sure...

[CSP]

Alternator or battery on the way out would be my guess.

[yobbo88]

New battery is in the car and sometimes the starter will engage and it kicks over perfectly. The battery is out of my v8 commodore so its more than enough also. Is there a way to test an altenator?

[Shounak]

Yes. You check its output. Very easy with a multimeter.

Check that everything is connected to the starter motor properly, that could very well be the problem.

[Pub247]

Sounds like the starter on the way out for sure. One of my old vk's did the same thing. Either replace it or an auto eleccy can replave the solenoid cap? which is what got done to mine. Also the other sounds like bushes in the alternator not sure if they're replacable as some bocsh regulters were, but once again replace or get a sparky to have a look at it.
An auto electrician going to cost more and he will probably replace both anyway.

[yobbo88]

But why does it go out when i shift into 4th gear?

[vlv8vic]

Check as many wires as you can find. I was starting to get these problems with the stanza and found that through years of hard love some wires had only been twisted and taped and were causing seemingly impossible problems.

Wanna juice up the engine? Have a nice 2L in the shed no one will buy, extractors, about 130000km with a reco auto box. Car they were in used to fly. until it flew

[Jecs]

id say the alternator if the lights are dimming down. its what happen to my mates datsun mini van. lights were slowly diming down then it just died.

[PRH]

i'd would checking all ya earths,the alt would be externally regulated if it has'nt been replaced,the alt light is turned off via a relay in the reg itself,from memory the reg 831240 ? is up on the LHS inner guard.
Phillip

[yobbo88]

id say the alternator if the lights are dimming down. its what happen to my mates datsun mini van. lights were slowly diming down then it just died.

The lights will dim down slowly and then the sound system cuts out but only in 1st, 2nd and 3rd gear but the car will keep running fine. As soon as i shift into 4th the lights will come back up to full strength and the stereo will come back on though.

i'd would checking all ya earths,the alt would be externally regulated if it has'nt been replaced,the alt light is turned off via a relay in the reg itself,from memory the reg 831240 ? is up on the LHS inner guard.
Phillip

I do hear a noise like a relay clicking on/off when shifting into 4th and coming back to 3rd/2nd/1st so it might be that. I'll check it out.

[yobbo88]

yeah i cant find any relays and its driving me nuts, but i keep thinking it has to be an electrical fault as it goes away as soon as i shift into 4th. what wiring would be involved in a 79 gearbox? reverse lights is all i can think of...

[yobbo88]

Ok so today i've had the starter motor apart and replaced the brushes and put it back together and it worked... sort of. It didnt work the first time i tried but then went for a drive and stopped on a hill then tried again. It started.

So i think i've fixed that problem but the charging problem seems to be affecting starting now as its not getting enough power to the starter. yes?

this is annoying.

[yobbo88]

A few more tests done.

Disconnected the negative battery cable while the car was running in neutral and the car turned off straight away (my poor battery!) with the car in 4th the car will continue to run with the connection off. Help a brother out!!

Tested the voltage of the battery with the car off got about 8.5 volts.
Tested the voltage of the battery with the car on in neutral got about 8.5 volts
Tested the voltage of the battery with the car on in 4th gear... 13.5 volts!!

This is crazy.

[VRV8_Matt]

there must be something in the box that is grounding when 4th gear is seleected.

go through all your earths and check and clean them