Ukrarex

iTrader: (1)

I recently swapped a sbc350 in to my 1987 na rx7 and im having a hard time keeping the battery from dieing. I wonder if any body could help me find where the voltage regulator is, cause im guessing when i cut the emissions wiring hurness and reconected the wires for the alternator i might have hooked it up wrong , so know im gona try to run the wires straight from the voltage regulator.

ps if any body needs stock na rotors or irons, oil pan, startor. i can get them to you pretty cheap.

HAILERS2

The voltage regulator is internal to the alternator on RX-7.

Ukrarex

iTrader: (1)

Oh great so i just have to run like 10 gauge wire back to the positive post on the batery, or should i run in to the 80amp fuse? Thank you for letting me know it has an internal regulator that makes things so much easier.

HAILERS2

You also need to run the two wires that go on the small alternator plug. One goes to the CPU and DESPITE what others might say, is the excitation voltage for getting the alternator up and going once it starts turning. This is a White/Black wire on a normal series four car and comes from the CPU like I just said. The Large plug on the CPU is where you'd find this White/Black wire.

On a series four non turbo car that White/Black wire was a part of the harness that attaches to the engine (EM harness). That EM harness connected to the Front harness and traveled over to the drivers side of the car and entered the CPU on a White/Black wire on the large plug of the CPU.

Normally if the small plug is connected to the series four alternator and if the key is put to ON, engine Off, the voltage on that white/black wire is 1-3vdc excitation voltage for the alternators field. The 1-3vdc on that wire means to me there is a voltage divider inside the CPU that creates this 1-3vdc instead of a reading of approx 12vdc/batt voltage, prior to startup.

Yeah, run a large gauge wire of approx the original size to the ENGINE bay fuse box. It attaches to the 10mm wrench size bolt on the aft side of the engine bay fuse box. In the middle of that box and covered with a plastic flap.

The other wire on the small plug is a switched source of batt power that normally comes from the ENGINE fuse and is switch on/off by the Main Relay.

ericgrau

iTrader: (1)

The voltage regulator is inside the alternator. The little plug on the back of the alternator connects to it. A bad or disconnected regulator should make your voltage too high, not too low. If so, don't drive like this for too long, since it may damage electrical components, and turn stuff on to keep the voltage under 15V. If your voltage is too low, your problem might be something else.

Auto parts stores will diagnose your alternator and battery for free, but they probably won't be able to tell the difference between a bad alternator and a disconnected regulator. So check the regulator connection yourself first. If the alternator or regulator is bad, do save the warranty info on the replacement alternator in case it sucks and fails in a few days or months. Just the luck of the draw there.

Ukrarex

iTrader: (1)

Thank you, ok so now i know where to run the main wire to the fuse box, but my 350 engine is carbureted so i dont have a cpu, the whole emission harness was cut off except for the wiper motor wiring. Is there a way to connect the voltage regulator and make up for loss of the cpu ?

HAILERS2

The CPU is not a ECU and is located left of your drivers left foot. That said, you can find a switched source of batt power for the alternator near the battery.. Its a green.......six socket connector connected to nothing. One of the wires is black/white in that connector. It is a switched source of batt power.

Run a wire from there to the back of the alternator. To the top terminal in the jack on the back of the alternator (there are two terminals there that form the letter * T*. Its the top of the *T* that you put the switched power to.

Just forget the bottom terminal. If the alt does not start charging right away when you start the car, just rev it up a bit and the residual magnatism(sp) in the alt rotor will self excite the alternator and it'll charge from there on during the drive.

Ukrarex

iTrader: (1)

Thank you vary much, ill post how it goes and maybe some pics haha