one wire alternator

[Tommy Dat]

Good evening All, 

 

I replaced my '77 200sx alternator with a '78 alternator with internal regulator.  I am still having issues with the battery holding a charge (recently had the battery tested at parts store and it was good).  I have been stranded a few times when the car will not start (voltage meter shows very low volts).  tonight the lights are very dim inside and out.  I am considering installing a one-wire alternator.  Is there a recommended brand/model?  others with success converting?  If these questions are answered in other threads please provide link.

 

thanks very much

[datzenmike]

Likely the choke heater relay is still on. On my 710s both conversions to internally regulated alternators will unfortunately wire the choke heater relay on at all times. Now the power to the choke is off with the ignition, but the relay coil is still active. It's like leaving a small drain on the battery. I noticed that over a weekend the battery was low, a long weekend and you couldn't start the car Monday. Disconnecting the relay works but then the choke heater doesn't do it's job.

 

On the carburetor at the back are two wires, a Blue one for the choke heater and a Red one (may have a black sheath covering) for the idle cut solenoid. Join the Blue wire to the Red wire and it is now on a separate power supply that turns off with the ignition. Unplug the old choke heater.

[thisismatt]

Did you bypass the external regulator (I'm assuming it had an external because you mentioned the new being internal)?  Did you check voltage at the battery with the engine running? It should read no less than about 13.5v.

[banzai510(hainz)]

by a 77 alternator and youll be fine.

other wise youll have choke heater ON all the time draning battery.

 

what you do with the volt reg? this needs be modified.

Edited October 6, 2023 by banzai510(hainz)

[Tommy Dat]

I did a Weber conversion.  The only wire I have connected to the carburetor is a red wire.   There are 3 wires that I taped together that do not connect to anything.  (green, bluish green and black).  Trying to upload a pic here but having trouble.  what image host do y'all use?

 

when I changed the alternator from a 77 to a 78 I removed the external regulator and my buddy used a jumper to bypass the external circuit. 

 

 

[banzai510(hainz)]

9 minutes ago, Tommy Dat said:

when I changed the alternator from a 77 to a 78 I removed the external regulator and my buddy used a jumper to bypass the external circuit. 

 

That would seem correct.

 

do the test light thing . If you have a radio with a clock it might show up as a drain. but do this and pull fuses or wires going to the carb or those jumpers at the volt reg and see if test light goes out

 

Edited October 6, 2023 by banzai510(hainz)

[banzai510(hainz)]

maybe the alt just went bad. Disconnect the +wire . Maybe a diode shorted out also.

[Tommy Dat]

thanks,  just used a multimeter on the battery posts with the engine running-  only 11.35V.  when I turned on several accessory items it dropped to 9.5.  Before doing anything else do I first need to take the alternator to a parts house and have it tested?  This alternator was just purchased a few months ago....ugh

 

The only other thing that I have noticed is that the fuse for the dash lights was really hot.

[thisismatt]

The external regulator needs multiple wires jumped, two pair. If you have low voltage things will get hotter as they draw more current.

 

Have you changed anything else? Does your ignition light in the dash come on when you turn the key to ON?

 

[Tommy Dat]

 

 

not sure if this opens an image?  I am struggling with figuring out how to post a pic.  this shows how I have the external regulator jumped currently

 

Edited October 6, 2023 by Tommy Dat
forgot text- remove link

[Crashtd420]

Just now, Tommy Dat said:

https://app.gemoo.com/image/detail/568968885909094400

I assume that's a photo link....

Wants me to sign in.... cant view....

There should be an add files window in the response box.... try using that. ...

[Tommy Dat]

yeah, sorry.  I only see "insert image from URL" and when I insert the image you can only see the link.   I will keep playing with it

[Stoffregen Motorsports]

15 hours ago, Tommy Dat said:

Good evening All, 

 

I replaced my '77 200sx alternator with a '78 alternator with internal regulator.  I am still having issues with the battery holding a charge (recently had the battery tested at parts store and it was good).  I have been stranded a few times when the car will not start (voltage meter shows very low volts).  tonight the lights are very dim inside and out.  I am considering installing a one-wire alternator.  Is there a recommended brand/model?  others with success converting?  If these questions are answered in other threads please provide link.

 

thanks very much

I use a Bosch ALRACE1 in my race car. It is one wire and has a very sturdy, yet compact frame. You would have to come up with some mounting brackets, but it's a very good alternator and may be worth a shot.

 

https://www.amazon.com/Bosch-ALRACE1-0124120006-New-Alternator/dp/B00427PMJQ

 

[Tommy Dat]

 

 

finally think I may have it figured out.  this shows my current set up

[banzai510(hainz)]

I dont see anything.

Maybe the alternator isnt even get turned on energized.

Otherwise take it back to get checked

 

you running off that battery

 

if running a few months with it like this already and was fine then most likely the alt is bad.  I only got 8months to 1.5 years with O riley and Autozone alternators and starters on daily dirvers

Edited October 6, 2023 by banzai510(hainz)

[datzenmike]

 

Needs one more jumper. White to Yellow and White/Red to White/Black.

 

In addition unplug your choke heater relay it's no longer used.

[banzai510(hainz)]

weird how this was working for months you said

Edited October 6, 2023 by banzai510(hainz)

[Tommy Dat]

 

It has been a project that I thought I had about wrapped up.  I would drive it often during the restoration but here lately I only drive it every several days.   Always something....

 

I will investigate all the issues that y'all have recommended.   Thanks very much

[Crashtd420]

1 hour ago, Tommy Dat said:

 

 

finally think I may have it figured out.  this shows my current set up

I see these....

Looks like only 1 jumper for the bypass of the regulator.....

 

Definitely check the wiring over....

[Tommy Dat]

 

 

 

Update:  I removed the red wire from the choke heater (unplugged it),  added the second jumper wire and charged the battery.   Today,  with the engine off the battery shows 13.6V,  with the engine running the battery shows 14.5V.  The lights are still dim but I have not explored other possibilities for that.  The dash voltmeter now reads 15ish volts when I am driving down the road.  I will drive the car as is and see how it performs.  Should I be concerned that the dash voltmeter is reading high?

 

thanks again for All of y'alls help with this.

[datzenmike]

Remember what I said. It's the relay that is on. The coil inside doesn't draw much power but over a long weekend it will discharge your battery.

[thisismatt]

Clean way to jump the regulator plug is to use the regulator wiring & plug to make the jumpers.

[banzai510(hainz)]

19 hours ago, Tommy Dat said:

dash voltmeter now reads 15ish volts when I am driving down the road.  I

Just compare it with a multimeter. then put lights on and heater and see

[iceman510]

If a voltmeter reads 14.5 at the battery when running you are ok.  I would trust that before trusting the accuracy of the dash gauge.  

 

Remember to check this with a charged battery.  If the battery is low the system may charge higher to compensate.  Best to always check the performance when the battery is full.

[banzai510(hainz)]

buy soemthing light this for the cig lighter.  The dash gauge is most likely fine.

I have a vesion of this using indication diodes. I can detect a failur coming usually before the ALT light ever comes on. Like draining the batter wwith lights/heater on when driving up to speed Ill see Im not charging just running off the batter till your on side of the road. So as I see it I head home before batt goes bad. Or a weal ALT during day is fine at Night with lights on or at idle not charging above 12.5 volts sign of weak alternator.

PS dont drain the battery either

 

https://www.amazon.com/12V-24V-Digital-Voltmeter-Vehicle-Motorcycle/dp/B09726J6KQ/ref=sr_1_16?crid=2IHTEOMQ7QKZA&keywords=voltage+alt+tester+cig+lighter&qid=1696867482&sprefix=voltgage+alt+testoer+cug+lighter%2Caps%2C123&sr=8-16