Adam

i think there is a ground problem in the tail lights or somewhere in the system

WAYNE88N/A

All right, rxspeed, back on topic, lol...If you want, try treating this as a short, then...

Disconnect at least one battery terminal. Read the battery posts for voltage. Nice and steady? No? Bad battery. Yes? Proceed...

Pull the top positive cable off of the alt, don't let it touch ground (or you'll blow your main fuse). Reconnect your batt terminal that was removed...Pull every fuse but the main in your engine bay fuse box. Test the battery posts for voltage again. Nice and steady? No? Then perhaps something fed by the batt hot bus is screwy (first two top rows of fuses in your cabin fuse box). Yes? Then it's the alt voltage reg, or something fed by the other main fuses in the engine box.

I doubt it's a ground issue, unless the main ground at the left strut tower or the starter area is either very dirty or very loose. I think it's an alt problem, or something related, such as improper pulley size, just in case you've played with that...

Hailers- I'll buy mum's theory, it makes sense. It's just very weird that an entire stator's output would be relegated to "sensing voltage" duty, instead of being used for output power. It doesn't take a whole lot of power to run field excitation voltage, certainly not 1/3 of the alt's output. Makes for a very inefficient design. But works, I guess

rxspeed87

thanx wayne I will try that tomorrow and post results.

as far as pullies it is the one that silverrotor provided and others didn't seem to have that problem. also shouldn't the alt have no effect when the car is off?


though I did notice as far as resistance goes I have about 5Ohms resistance from the battery to the bolt holding the alt but I assume that shouldn't be enough to cause a problem.


and as weird as this might sound but could coolant be an issue? I did a voltage test on the coolant and pulled .5-.6v out of the coolant to ground and I know that is a little high compared to what it should be....... NEED TO CHANGE THE COOLANT!!!!

hugues

I think the alt. is shot because it was not wired correctly. Probably, the S terminal was not seeing batt. voltage at all times. The above is just an educated guess.

I would have the alt. tested for proper output.

http://www.geocities.com/huguesdc1/charging.html

at the end, I talk about the s5 alt to s4 conversion which is similar to the FD alt to s4 conversion, because s5 and FD alts are of the same (Sensing load).

Note that you may still have problems in the wiring but since you have an FD alt, you have to make sure it's properly connected to eliminate one potential problem that is known.

hugues-

WAYNE88N/A

You know, that should be another prerequisite for being a forum member- reading Hugues's site...LOTS of good info, for you guys that haven't been in there before-read it

And rxspeed- did you say 50 ohms, or 5 ohms, for the alt-to-battery (neg terminal, right?)resistance??? And now that we've all asked you several times (in different ways), did you ever verify that the wiring at the back of the alt was correct?

HAILERS

If you still have it, chunk the old alternator back on and see what happens.

Lights dim when braking......... If severe......pull your brake switch off. Ohm out the switch when it is made. If the resistance is very high ...replace it.

Most brake switches are two in one...or two connectors on one switch. Put the brake wire switch on the circuit internal to the switch that has the least resistance and put the other (cruise control switch) on the other circuit. In other words swap places with the two connectors.

Some brake switches have but one two prong connector. You can't do the above with that one.

rxspeed87

the resistance was 5 ohms not 50 ohms sorry

I did verify it was correct

waiting for my company to get here to verify the rest of the stuff though :-)

rxspeed87

the old alt was a lot worse then this one when hitting the brakes
with just the lights on the car sat near the 13 marker
if I turned the defrost on I was pulling around 11.5 v or so


hitting the brakes they would dim as well


with the new alt the lights dim but it is more or less a flicker style dim
all lights get dim to maybe 50% lets say but then come back on at maybe 80-90% of what there orig brightness was.


this sux mixed with the unstable batt voltage when the car is turned off

but hey it leads to learning right?

btw where is the brake switch?

rxspeed87

since I don't have the stock wiring on the alt plug I was trying to verify wiring with a volt meter. understand one is supposed to have constant voltage right?
well with the car turned off I have 0 volts to the top plug and around .5-6 volts on the bottom plug


when I turn the key on I get around 12.x volts to the top plug and around .3v to the bottom plug

which plug the top or bottom is supposed to get the full 12.x volts at all times?
and whats up with the bottom plug only getting less then a volt?