Rxtree

Hi everyone,

I'm such and idiot. After searching and searching I can't figure out how to properly set this up.

I read somewhere that I'm supposed to put ignition power to the upper spot in the "T" connector of alt. Does anyone know a good source of ignition power for the alternator nearby?

There's a big mess of wirey crap left behind from my twin diz and all the afterburn thingies. It would be great to find something around there.

Also.. my Haynes manual sucks. I can't find what color wire lights up my "charge" light in the inst. cluster.

Thanks!

Siraniko

iTrader: (13)

The 81-88 alternator has a 2-wire terminal in the back, one of which need a 12-V for the alternator to charge. The igniter or points have 2 wires coming from the coil. the one coming from the coil's + terminal has 12-V that you can use.

Rxtree

Thanks, bro!

Rxtree

I failed... I think.

Whenever I've suspected a car that isn't charging, I'd just lift one of the leads off the battery and if it stalls it wasn't charging.

I wired the alternator field lead (not the one marked "L") directly to the + of the coils. When I lift the battery lead it dies.... bummer. Did I miss something?

Rxtree

Ok I've confirmed switched 12v at the alt. My coils had no 12v maybe because of my msd box.. Who knows. All I can say is that it still stalls when I lift the batt lead. My crap volt meter jumps all over the place so I don't get a real reading. 12.5 when off and crazy bouncing when running.

I'm getting really bummed. This isn't rocket science.

Siraniko

iTrader: (13)

while the engine is runing, use a test light and locate another source of 12V, then disconnect the battery. its that simple and you dont need to be a scientist

Rxtree

There has to be some other problem... I think I'm going to try to put a jumper from the alternator output/load or whatever it's called directly to the battery. Then test again.

The signal/field or whatever the upper lead (not the L) is now connected to the black wire that used to go to the coils but is switching the MSD box. I think that's the true Ignition wire. It's probably the same one that's going directly to your coils.

I just realized that the jumper idea is a waste of time because I'm getting a constant 12v when nothing's happening.....

So at this point I'm going to say that, even though this is a new alternator...the alternator's fried. I guess I should start searching forums to test and confirm that now.... Booooo.

Thanks Wacky. I took a look at the other thread I was reading and it was you helping someone else that threw me that bone.

Rxtree

Things are getting even more confusing.

I thought maybe the alt was the prob so I brought it back to the rebuilder. He said it checked out fine. I asked him how he proved it? He said he used the "L" to give it field and then load tested it. I was shocked. I made him point to the lead on the alt where he was talking about just to make sure we were on the same page before I left for home to try it again.

Got home, tried putting 12v to the "L", nothing. Tried the other one.. nothing.

Remember, all I'm doing to determine this is lifting the battery and watching the car die. Maybe it's working and I'm just too dumb to know.

Gey! I want to burn up the streets of Vancouver for this fine weekend of weather we're getting.

The rotary gods must be angry at me.

Siraniko

iTrader: (13)

Try another alternator if I were you. 81-88 including TII.

Rxtree

Hey Wacky!

As soon as I took it for a drive the charging sys woke up. There was nothing.. but when I got to about 3000rpms I saw the amp guage bounce up to the + side. It stayed that way until I shut it off. I fired it back up and same thing. No charge until it wakes up at 3000 or so. Have you ever seen that?

My last alternator cooked my battery. I see the amp guage is 1/3 up the + side. I figured it would be at 0. Does the + mean it's going to overcharge you think?

When the car is running. A voltmeter at the battery showed 12.8v and slowly creeped past 13v over the course of 1min. Revving the throttle made no difference.

turbo_dave

iTrader: (50)

i have seen this on alot of cars but the difference is they dont run the 12v ignition to the terminal in back of the alt,they usually just have the 12v direct on it.thats why i like to run the s5 alt they are easier to work with and they dont need the 12v ignition.but seems you have everything correct,here is a diagram i use.

Rxtree

Thanks for the diagram. I had a look at that when I was on my search for info. It's such a crap feeling when you use the info that works for eveyrone... and it doesn't work for you.

I don't mind how my charging system waits for 3 grand before it starts working.. as long as it's working properly when she's goin.

Is it the voltage being too high that cooks a battery? My volts seem ok. I'm just concerned about the amps trickling into my battery when it may not need it. Does that make any sense?

If someone can tell me what their amp gauge shows when things look normal that would be great!

One thing I did notice about your diagram is how you're using the sense line directly to the battery. My alt shop said and I also read somewhere that it's a good idea to use a "sense" voltage from a switched source that goes through as much of the stock wiring as possible so the "sense" can put wire resistance into the regulation equation.

Whew that was a lot of finger flappin'.

Siraniko

iTrader: (13)

S5 alternator: you can disregard the extra wire that goes to a 2-wire pigtail. but there is 12V there that you can you can use for other things

Rxtree

Does anyone have a working amp gauge in their rx3? I'd like to know what it reads when running. Mine reads (what looks like) 15amps. Does this mean it's producing too much amps and overcharging?

Rxtree

Well the more crap I read on the internet the more I feel like my battery is overcharging.
The problem with amp gauges is only the old cars use them.

I could have swore my needle was always just barely on the + side at all times back in the day. Now it's way on the +

I've had to go to Mopar forums, marine forums, muscle car forums... Finally I had someone say that if I see a big + on an amp meter it means you're overcharging.

Sheeeeesh. I hope this helps a fellow Rx3 guy somedays.

BadAssRX-7

the amp meter is showing only the amps that are getting added( charging) to the battery/ sys. I have both amp and volt in my 74 repu and a 80amp alt from a fc. the amp hardly shows it on the + side. yet the volt will bounce around. If you have a large drain on the sys like lights, fan ect. it should show a higher amp output. The only issue i have is that my battery will drain down after 3 or 4 days so i just unhook the alt. when im done driving it and it will go for a long long time before needing a little boost.