Hey guys.

I have an FD alternator with a dual belt alternator pulley, and lately my lights have been flickering along with the tachometer shooting all over the place randomly.. my first guess was battery/alternator problems.

According to a digital multimeter I am at or above 14.5 volts consistently, however, it rarely jumps above 15.3...

I hear that 14.5 is too high. Is that a fair assumption? If so, should I be looking at a new alternator (possibly back to FC?) or maybe dump the dual belt pulley?

I appreciate the feedback.

 

Acording to the fsm 14.7 and no higher, at the alternator itself.

Check the connection on the small plug that connects to the alternator. The plug is common to many cars, so it can probably be bought at NAPA. I just had this problem and that was the fix.

 

FWIW the ECU is only designed to accomidate 15 vots maximum

 

The Haltech or the stock ECU?

Don't worry, I realize the gravity of this situation, haha.

 

What is too low to run for a TII?

I've got an FD alt but think it's dying.

I'm pulling 13.0-13.3 volts with headlights on at night. My car hesitates and surges in boost. I'm assuming that's too low to keep up with 10psi?

 

Sounds like you wired the alternator wrong, rewire it correctly and you should be ok.

 

You need to see at least 13.4 at all times or you're draining your battery.

 

A high voltage generally means that the plug at the back of the alternator has come loose or is improperly wired.

Low voltages are commonly a failing alternator, or the 20 year old stock alternator power wire dying. These wires are almost always in bad condition. Running a nice new 8 gauge wire up to the fuse panel makes a huge difference.

 

lol sorry, didn't notice the Haltech in your sig. That number was quoted from a post by Icemark regardign the stock ECU.

 

Keep it under 15.0VDC, and you're good.
Anything above 15.0VDC risks burning stuff out.


-Ted

 

don't you have to mod the FD alternator to work in the FC? I'm curious myself.

 

It's wired right.
Good idea Aaron. I haven't screwed with the stock line so beefing it up may help

I'm assuming I just connect it on the main fuse?

 

Yep, connect your new wire in the exact same place as your old one.

 

I've got some 12 gage lying around. Do you think that would be good? or is 8 gage the minimum? or was that just an overkill size?

 

Digitech, you thread jacker!

Naw, glad this got some attention...

@Ted: A while back I burnt through about 3 stainless steel clutch lines, new grounding wires and a different grounding setup fixed that problem...

but... I still have that light flashing and tach. bouncing.

Speaking of the tach bouncing, I've noticed that every once in a while, it seems as if it will jump up to double what the RPM is.. for instance.. if I'm cruising at about 30 in 3rd gear, the tach will bounce (and sometimes stay) inbetween 5500 and 6000 rpm, which is basically double what the RPM really is- see what I mean?

Thoughts?

 

Yessir, you do. The only reason it is even on the car is because the previous owner had a LOT of stereo equipment in the car (6 amps, 2 12" subs, in-dash DVD, etc) that I am currently taking out.

 

No, you don't. The alternator fits perfectly with the addition of a pully with the correct backspacing. If you consider this a mod, then I guess you have to mod the alternator...Aside from that you do need to change the wiring on the car side, so you have to mod the car...

 

Oh, I was under the impression that he wanted to know if it was just a direct bolt-on. Grazie for correcting me.