Wow it's been a while since I last visited here! But anyway guys, can you help me out here.


Anyway the first few links are for my alternator. I've put a series 4 in (I think it's a 4... it has an 80A capacity, and it's a Mitsubishi alternator). I just want to make sure that it was wired up correctly because my car goes flat after like 3 days of non-driving.

I know there is something about the L (light) and S (sense) points, but how do I know if it is done correctly....anybody?

Here is the link to my alternator

http://www.geocities.com/intercepter_05/Rx7001.JPG
http://www.geocities.com/intercepter_05/Rx7003.JPG

Secondly, here are some loose wires that I wanna know what they are for!


This I found the other day... it's right near my solenoids & air/carby assembly. The white connector is pointed out because that is where it comes from.

http://www.geocities.com/intercepter_05/Rx7031.jpg



Thirdly, here is another loose wire I found. This goes under the oil cooler and down to what appears to be the sump... altho all my dials are working fine!...

http://www.geocities.com/intercepter_05/Rx7036.jpg
http://www.geocities.com/intercepter_05/Rx7039.jpg

Any help is appreciated!

Here are some pics of my rx7 inside... I know you guys dont have a backseat, so check it out & let me know what you think!

http://www.geocities.com/intercepter_05/Rx7014.jpg
http://www.geocities.com/intercepter_05/Rx7015.jpg
http://www.geocities.com/intercepter_05/Rx7020.jpg
http://www.geocities.com/intercepter_05/Rx7021.jpg
http://www.geocities.com/intercepter_05/Rx7022.jpg
http://www.geocities.com/intercepter_05/Rx7023.jpg
http://www.geocities.com/intercepter_05/Rx7026.jpg

 

Put a voltmeter across the battery when the engine is running at about 1200rpm - if it's less than 13v you have a problem. Should be somewhere between 13.5 and 14.5 as a rule.

 

Sorry for the picture restrictions guys...should be ok in 60mins.

 

Welcome back. I've alway been a fan of your paint job. Well, I can't see the pics but I will give this a shot. First off, from your description of the alt it is an S5. S5 & later are L/S style. Earlier ones are L/R. Also the S5 are 80 amp while the S4s are 60 or 70 amp depending if turbo model or not. Read this thread. This will solve the battery drain problem.

https://www.rx7club.com/1st-gen-archive-71/electrical-2nd-gen-alt-1st-gen-388262/

For the connector: is it shaped like the solenoid conectors (vac advance, etc.)? If so, that is the A/C solenoid. Can't see the pic, so this is a total guess.

For the third, the wire goes down to the oil pan, correct? Depending on the connector, it is either for the oil level sensor or for the oil temp (only used for the sub-zero injection)

Hope this helps.

Kent

 

Now that I can see the pics, you definitely have an S5 alt. It looks like you were close with the wiring, but it appears that your L and S terminals are switched. The B wire should be closest to the output terminal (S terminal) and the WB goes furthest away (L terminal). The S is for sense and the L is for the alt warning light. I saw that you labeled the output as earth. Is this a mistake or do your cars have a positve ground setup?

I am not sure about the loose connector. It is not the AC solenoid connector as I was guessing earlier. Maybe one of the carb guys knows.

That last wire is the oil level sensor (lights up the oil level warning light when the oil level is low).


Car looks nice. I didn't get to see all of the pics (It won't let me access pics again).

Hope this helps.

Kent

 

Bump!

 

Can you explain in dumbass terms what I need to do with the wiring to make it ok!!!! I thought that was the earth but I think I am wrong! HAHA.

Thanks for the compliments about my 7, btw, all the pics should be ok now.

 

All you have to do is switch the wires on the back. Make it so that the black wire is closest to the output post and the white w/ black stripe wire is furthest from the output post.

 

Ok thanks I'll give that a shot.

Is it weird though that the car stays charged if I drive it every day but after 2-3 days it goes flat....especially because the current set-up is the wrong way around, how is it getting charged then?

Sorry I just wanna get to the bottom of this...

 

Well, what happens (as shown in that other thread) you get a current draw when the car is off because of the difference in the regulator design between the earlier alts (like ours) and the later alts (S5 & later). The way that you have it will charge the battery (I'm actually suprised that it isn't overcharging the battery). What does the voltmeter read?

In the S4 and earlier alts, the regulator has an output for the alt warning light and a connection that goes to switched ignition. This regulator is designed to turn off when the car is off.

For the S5 & later, the alt adjusts its output based on the sense voltage (S terminal). If the voltage drops, the regulator will detect it and increase the output of the alt to compensate. Since you have the alt warning light connected to it, it should see no voltage. This means the the alt has probably been putting out its full capacity to try and compensate.

This is also why the battery drain occurs. Most people wire the alt warning light correct, but connect the S terminal to a switched source. When the car is off, the alt sense the the S terminal now has no voltage and tries to charge the battery. But, the engine is not running. This creates a draw of about 1 amp or so and will drain the battery within a day or two of not driving. These alts are designed to see voltage at the S terminal at all times (car running or not).

You can see the wiring on that thread that I posted. That will verify what I'm saying. I also have an S5 alt on my car and I like it a lot. The voltage is much more stable than with my old alt.

Hope this makes sense. You will see in that thread that I posted a link to teamfc3s. If you look at that link you will see the massive confusion that putting a S5/S6 alt into a S4 car caused. Some of the problem was because the wiring diagrams that some people had posted to make the alt swap work were incorrect.

Kent

 

I just want to make sure. The black wire that you have connected currently to the L terminal is connected to the alt output post, correct? That is how it looks in the pic, but it is kind of hard to tell.

 

On the diagrams the S5 alternator doesn't have a big black stork coming off it. You sure mine isn't a s4?

 

Yes, that black post is removable. It is an S5, you can tell by the plug in the back. The S4 alts have the same plug as our alts (shaped like a T). The S5 and up have a plug like yours does. The alt that you have is definitely from a S5 car. I can even tell that the alt was off of a turbo model. The turbo model has the plug in the back of the alt, while the NA models have the plug in the top of the alt. There is a good pic in that thread were DirectFreak posted info from the teamfc3s site. You can tell in the diagram the difference between a S4 and a S5 alt.

Kent

 

Thanks Kent..I'll swap the wires and see how it goes for a few days.

BTW.. I was still avg 13-14v

 

Here is the diagram from the other tread:


which means that the S terminal will go directly to the battery (preferably with a fuse). the L terminal goes to the White/black wire and the black/white wire for the alternator is no longer used.


Now Im gonna do a little thread hijacking because Im doing the same thing with the 13b-RE alternator. Below is a diagram of the alternators connector, and its plug. On the plug itself, what would be the S terminal has a - sign, and the other has a + sign. just wanna make sure that I still have to do the same thing or if I should invert them because connecting a (-) directly to the battery does not sit well in my mind.

 

Yes, you will want to wire it the same. Those appear to be the same colors as the FD alt. W/B goes to the cars W/B wire (alt light [L terminal]) and the other is the S terminal (connect to alt output post). I think the + and - symbols are on there because it is likely a general connector and is used in other applications. There should also be a diagram on the alt showing which plug is L and which is S.

Hope this helps.

Mr_Rx7_Au: Good luck. Let us know how it works out.

Kent

 

sounds good thank you

 

Sorry to thread hijack, but Kent, you seem to know a lot about alternators, and I am having issues and wondering perhaps if my connectors are wired up wrong.

I think my alt is from an RX-7 but I'm not sure which model.. The connector fits fine. Heres a picture of it:


I should be right just plugging that straight in yeah?

 

Well, it's not really a hijack if we are on the same subject. The wiring appears to be correct. As you see on your alt, there is a diagram that show the top as being the R terminal and the bottom being the L terminal. This is how it is on all the S4 and earlier cars. I'm not sure if that is off an RX-7 or not. It looks like maybe an '80 model but may be off of some other car. Does it have any other markings on it (current rating, model number, etc.)? What issues are you having (not charging, battery drain, over voltage, etc.)? I am not sure how it is in Aus, but in the US most autoparts stores will test your alt for free.

Let me know what kind of problems that you are having and maybe we can figure it out (I don't think it is a wiring issue, though).

Kent

 

Hmm well with my headlights on, the voltmeter is reading about 12.8 volts and in low rpm (under2000) i am having weird problems like poor throttle response (it is efi). My guess is that the alt is not putting out as much as it should. It is 70amp i believe. I will have it tested though and find out what it is for sure. Cheers

 

Sounds like it is not charging correctly. Maybe it's bad diode(s) or a bad voltage reg. The only way to find out is to have it tested. Good luck.

Kent

 

I switched my wires around Kent. Seem to be working better.

I did read that is is a good idea tho to wire your S straight to the battery + instead of the B terminal, via a 30amp fuse and 4mm cable....

I'm gonna try that tonight to see if it helps, with the way it is set up now, Im getting a constant 13v charge, but I should be getting 14v constant... hoping this will make it work!

 

O-K so I had it tested.... he said it was charging fine, as sure enough when I tested the charging voltage on the car, it was about 13.8v...

It's not likely is it, that the alternator is being intermittent, say when it heats up something stops working in it ?

I'm guessing its bad wiring somewhere causing my problems. After fiddling around I drove around twice last night without a problem heh.

 

That is good that it is working. It wouldn't hurt to do the separate wire with the fuse. Is the voltage reading based on what the dash meter is saying or did you actually test with a multimeter? I ask because I know my meter in the dash reads about 1v lower than actual. So if you are going by this number, your voltage output is probably fine and you were probably over charging the battery before.

There are a couple things that could be going on here. Was the alt tested under load (out of the car, hooked to a machine)? It may be that the alt is not putting out enough current to keep up with the load.

This could be caused by either:
1. bad diode in the alt reducing its total output capacity.
2. the alt has a smaller output than you think. It looks like an early (S1 or S2?) RX-7 alt. If this is the case, it has only about a 50amp max output. I may not be able to keep up with the fuel injection, lights, etc.

The resulting low voltage from either of these cases can cause hesitation and other problems on fuel injected cars.

The other posibility is a bad ground, alt output wire, battery terminals/cable. I would try to just throw a used alt in there if you can find one cheap. The turbo S4 came with a 70amp that plugs in the same as what you have know or you can go with a S5, but you would need to make the wiring modification.

My meter use to drop with my old alt on my GSL-SE (voltage never got low enough to cause hesitation, the SE came with a 60 amp alt) The alt shop found that it had a bad diode (still charged, but max output was reduced by 1/6). Now that I have a S5 alt, the voltage is very steady. I can turn on lights, heater blower, wiper, etc. and the voltage will barely drop at all.

Kent

 

Wow, you are the alternator expert! Hehe, Thanks for all the info there, I will see about further alternator testing once I have checked the wiring. He tested it was charging, I'm not sure whether it had a load on it or not... I was told this was 60 or 70amp when I got it, and it only cost about US$40..

So 1) ill check my wiring, if the problem comes up again, 2) have the alternator torn down and checked over and it's capacity determined.

Thanks Kent