Jump to content
SAU Community

Recommended Posts

alternator has been like this for a year now It works but i find if i park and leave the reds on or im listeniing to music for lets say 30min-1hr i have new battery dry cell type. But i find that when i start the car and drive with the air con for instance im looking at the battery power and its at 12.2 v and i take my foot off accelerate it drops to 11.9 and i get a warning beep from the turbo timer it eventually rises to normal level i think around 12.7-12.9v but i think my alternator might be on its way out i heard it should sit stable at around 13v, and i should b able to have the music on for more then 2 hrs right before battery drains??? can i get a recoditioned alternator or get mine recond? and how much am i looking at?

Link to comment
https://www.sau.com.au/forums/topic/323480-94-r32-gtr-alternator/
Share on other sites

Actually this morning as im driving it was at 13.3 v stable i put the air con on and it dropped too 13v-13.2 it just goes up and down a few point depending, see if the lights are on stereo are on etc, it will be at around 12.8 is this normal?

Your alternator should be working between 13.8v to 14.3v to maintain the electrical load.

Sounds like the voltage regulator is on its way out.

Once the engine is running the battery is "not " running the electrical items. The alternator is meant to carry the entire electrcal load. It will replace the charge to the battery after startup or draw from the battery if electrical items were used while the engine wasn't running, but once battery is charged the alternator just delivers enough current to manage the load.

What is the part number of your alt. Is it a Hitachi or Mitsi branded model.

I rebuild them from home, "may" have some suitable parts

Nigel

Your alternator should be working between 13.8v to 14.3v to maintain the electrical load.

Sounds like the voltage regulator is on its way out.

Once the engine is running the battery is "not " running the electrical items. The alternator is meant to carry the entire electrcal load. It will replace the charge to the battery after startup or draw from the battery if electrical items were used while the engine wasn't running, but once battery is charged the alternator just delivers enough current to manage the load.

What is the part number of your alt. Is it a Hitachi or Mitsi branded model.

I rebuild them from home, "may" have some suitable parts

Nigel

Is it visible from the engine bay? and what costs am i looking at?

GTRAAH, this happens to me as well. No matter how I drive, the voltage meter on my turbo timer won't go past 12.6-12.7, only time it ever goes past 13.0 is right after I cold start it then after a minute or so it drops back down to 12.6 again. Also if I leave the car parked for too long (eg. 2-3 weeks) without cranking it then my battery runs flat. If I listen to music for around 20mins without the car running then battery goes flat again. I've replaced the alternator twice already and have had to buy new batteries numerous times in the 4 and a half years I've owned it. The car's had this problem ever since day one and it's slowly driving me insane! :cool:

Edited by GT32
Is it visible from the engine bay? and what costs am i looking at?

Yeah there should be a label on it on the back/side area. Some are underneath. Might have to use a small mirror to spot it.

Cost depends on the alt model.

Also the part number will telle what amp the alt is.

You may need to use a 90amp model

Nigel

Nigel, when I replaced my alternators I've always bought one off an RB20DET motor. However, I run an RB30E bottom end. Are the alternators across the entire RB-series of engines all rated at different amperage? Should I be using an alternator that was taken off an RB30 as opposed to one off an RB20? I've always wondered if that would make any difference in my circumstance...

Edited by GT32
Nigel, when I replaced my alternators I've always bought one off an RB20DET motor. However, I run an RB30E bottom end. Are the alternators across the entire RB-series of engines all rated at different amperage? Should I be using an alternator that was taken off an RB30 as opposed to one off an RB20? I've always wondered if that would make any difference in my circumstance...

Some R31 Skyline RB20DET (red top engine) came with a 70amp. R32 RB20DETs should all have a 80amp. Then there is the 90amp used on R33's RB25 etc.

The thing is just because an alt came off a RB20DET engine doesn't mean it was the factory unit. Alt could have been swapped out at some stage.

In most cases the 70amp is fine unless you running some high power draw items, eg. big amp sounds etc. The 80 and 90 amp units will just cope better with the load.

You certainly do not have to match the alt to you RB30 block. But what I would suggest is getting the alt with the smaller pulley (69mm instead of the 73mm). That way the alt will be spun slightly faster. The alt in question would be the Nissan 23100-70T05 (Hitachi LR190-722) 90amp. It has the 8mm BAT bolt versus the 6mm on most others. Still a direct swap on all RB engines. You will just need to change the eyelet on the cable for the BAT terminal to 8mm.

I know of 17 different alternator factory fitted from R31 to R33 Skyline etc. Some made by Hitachi and others Mitsi. The odd Bosch on in Australia.

http://www4.wave.co.nz/~lakewood/Skyline/Alt.htm

Nigel

Some R31 Skyline RB20DET (red top engine) came with a 70amp. R32 RB20DETs should all have a 80amp. Then there is the 90amp used on R33's RB25 etc.

The thing is just because an alt came off a RB20DET engine doesn't mean it was the factory unit. Alt could have been swapped out at some stage.

In most cases the 70amp is fine unless you running some high power draw items, eg. big amp sounds etc. The 80 and 90 amp units will just cope better with the load.

You certainly do not have to match the alt to you RB30 block. But what I would suggest is getting the alt with the smaller pulley (69mm instead of the 73mm). That way the alt will be spun slightly faster. The alt in question would be the Nissan 23100-70T05 (Hitachi LR190-722) 90amp. It has the 8mm BAT bolt versus the 6mm on most others. Still a direct swap on all RB engines. You will just need to change the eyelet on the cable for the BAT terminal to 8mm.

I know of 17 different alternator factory fitted from R31 to R33 Skyline etc. Some made by Hitachi and others Mitsi. The odd Bosch on in Australia.

http://www4.wave.co.nz/~lakewood/Skyline/Alt.htm

Nigel

Nigel where you at mate if your in sydney i might come for a drive so you can have a quick look at it?

Nigel where you at mate if your in sydney i might come for a drive so you can have a quick look at it?

Hehehe sorry mate. I'm in Hamilton, New Zealand. If you can take some pics though and send them to [email protected]

Nigel

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • AHHHH gotchaa, I'll do that once I am home again. I tried doing the harness with the multimeter but it seems the car needed a jump, there was no power when it was in the "ON" position. Not sure if I should use car battery jump starter or if its because the stuff that has been disconnect the car just does send power.
    • As far as I can tell I have everything properly set in the Haltech software for engine size, injector data, all sensors seem to be reporting proper numbers.  If I change any injector details it doesnt run right.    Changing the base map is having the biggest change in response, im not sure how people are saying it doesnt really matter.  I'm guessing under normal conditions the ECU is able to self adjust and keep everything smooth.   Right now my best performance is happening by lowering the base map just enough to where the ECU us doing short term cut of about 45% to reach the target Lambda of 14.7.  That way when I start putting load on it still has high enough fuel map to not be so lean.  After 2500 rpm I raised the base map to what would be really rich at no load, but still helps with the lean spots on load.  I figure I don't have much reason to be above 2500rpm with no load.  When watching other videos it seems their target is reached much faster than mine.  Mine takes forever to adjust and reach the target. My next few days will be spent making sure timing is good, it was running fine before doing the ECU and DBW swap, but want to verify.  I'll also probably swap in the new injectors I bought as well as a walbro 255 pump.  
    • It would be different if the sealant hadn't started to peel up with gaps in the glue about ~6cm and bigger in some areas. I would much prefer not having to do the work take them off the car . However, the filler the owner put in the roof rack mount cavities has shrunk and begun to crack on the rail delete panels. I cant trust that to hold off moisture ingress especially where I live. Not only that but I have faded paint on as well as on either side of these panels, so they would need to come off to give the roofline a proper respray. My goal is to get in there and put a healthy amount of epoxy instead of panel filler/bog and potentially skin with carbon fiber. I have 2 spare rolls from an old motorcycle fairing project from a few years back and I think it'd be a nice touch on a black stag.  I've seen some threads where people replace their roof rack delete with a welded in sheet metal part. But has anyone re-worked the roof rails themselves? It seems like there is a lot of volume there to add in some threads and maybe a keyway for a quick(er) release roof rack system. Not afraid to mill something out if I have to. It would be cool to have a cross bar only setup. That way I can keep the sleek roofline that would accept a couple bolts to gain back that extra utility  3D print some snazzy covers to hide the threaded section to be thorough and keep things covered when not using the rack. 
    • Probably not. A workshop grade scantool is my go to for proper Consult interrogation. Any workshop grade tool should do it. Just go to a workshop.
    • In my head it does make sense to be a fuel problem since that is what I touched when cleaning the system. When I was testing with the fuel pressure gauge, the pressure was constantly 2.5 bar with the FPR vacuum removed. When stalling, the pressure was going up to 3.0 bar (which is how it should be on ignition).
×
×
  • Create New...