1 wire alternator install problem.

[notoptoy]

I would bet money that the white wire has come off of the back of the Ammeter, or worse, that the ammeter is fried. Simply reconnect the wire if off. If the ammeter is fried, you can bypass it by connecting the two wires together.

[C.Costine]

Vrosi963, it sounds to me like a fried ammeter. I installed a voltmeter and bypassed the ammeter with a 20 amp fuse. I called my friend who operates an auto electric shop about my 17 volts problem. He told me to check the wire that comes to the Vreg from the ignition switch, and it checked OK so I have ordered a new voltage regulator.

[Vrosi1963]

Ok do you have a part number or were is there a after market replacement. JW

[C.Costine]

Ok do you have a part number or were is there a after market replacement. JW

Vrosi, is you question directed to me?

[JT68]

Before you conclude the ammeter is dead or disconnected, there are a couple simple tests you can do to verify/test that hypothesis.

First, with the car not running, there should be just about +12V on the large white wire at the alternator (measured with respect to chassis or -battery terminal) +Battery voltage should be present whether connected to the alternator or not. It always should be there regardless of the ignition switch.

Second, that line should be able to source PLENTY of current (so never let it touch the chassis). Hook up a headlight or small 12v motor to it- a heater motor is perfect (again with respect to battery- or ground) with a couple test leads.

The headlight or motor should operate and the ammeter will swing slightly negative depending on the load.

If there is not 12v there or the test load won't work, the ammeter is fried or disconnected or poorly connected to the harness (corrosion etc)
If the test load operates properly and the ammeter deflects, that circuit is intact and you have other issues.

These are quick, easy, basic tests. Much easier than ripping into the dash.

J

[Curtis]

This will help you trace it out.

http://www.kendo-usa.org/datsun/datsun_ ... _66_67.pdf

[JT68]

Curtis' diagram reminded me, on early models, the large white wire from the alternator shares a screw terminal at the fusebox with the wire that actually connects to the ammeter, so if that junction is poor/corroded/melted/compromised, there will be no charging.

The two simple tests i spelled out above still apply, but this junction is another potential location for circuit failure.
J

[C.Costine]

Vrosi963, it sounds to me like a fried ammeter. I installed a voltmeter and bypassed the ammeter with a 20 amp fuse. I called my friend who operates an auto electric shop about my 17 volts problem. He told me to check the wire that comes to the Vreg from the ignition switch, and it checked OK so I have ordered a new voltage regulator.

The new regulator came today. I installed it started her up and the output was at 15.5 volts down from 17.8. I am going in a few minutes to get her registered. First time since 2002.




.

[Lorna c]

right on ! congrats on driving her again !

[greydog]

Isn't wa 5.5v still a volt or mouse high?
Dan

[greydog]

Sorry... isn't 15.5v still high?
Dan

[Nissanman]

Gee Dan I was just about to call a Medic!
Yes, normally the battery, unless flat as, would have 13.2 to 13.8V across it when the engine is running.

[C.Costine]

Sorry... isn't 15.5v still high?
Dan

Yes, it is, and it looks like I may still have a problem. At that time I attributed the 15.5V to just an initial high charge rate, due to the battery being a little low. However, yesterday when I went to take it for a quick drive it was missing and popping, and soon after I stopped it quit because my add-in 20A fuse had blown. There was a hot smell under the hood even tough the engine was not warmed up yet. I replaced the fuse and ran it back to the shop. It ran perfectly well then. I parked it and was not able to get back to it yesterday. After it died I noticed that the power lug on the Alt. was loose.

[Vrosi1963]

I installed a new voltage regulator and still no lights or starter function. I did notice when I flip the light switch up and down the amp meter gauge moves around .. I did notice a red wire coming out of the driver side firewall grommet that comes off the ignition key with 5 volts coming off it with a spade connector on it . Were should it go ? I see nothing

[dbrick]

If you are seeing 5 volts on a 12 volt system, unless its the ignition after the ballast resistor or the power from the gauge regulator, something is not right.
My 3 wire (somehow running on 2 wire) GM alternator crapped out, It had been charging high, 14.7-15.0 into a 10 year old, but still good battery for the last few years. 40 miles from home, it stopped charging. Found it was melting the 30A fuse from a bad connection right at the output connection, then after replacing the fuse, lasted 15 minutes, a few push starts here and there and it made it home at just about 8 volts. Luckilly the EI ignition still functioned that low. Later, after getting a new battery, while testing the alternator I was getting crazy readings, up to 40volts from the alternator with fuse removed. Replaced it with a spare alternator, and an un melted fuse holder it now 13.7 volts, into the new battery.

this is everything you may need to know about the alternator, and a good site in general.
http://www.madelectrical.com/electrical ... wire.shtml

If you decide to go full 3 wire, you can use the "B" brake warning light as a charging light. As far as brake warning function, the light comes on as the pedal hits the floor, so the car already has your full attention.