alternator pulley
 

I have a powermaster "high output" alternator and at idle with accesories my guage is reading below 13 volts, close to redline. Not only does it read that but my headlights get dim and turn signals barely blink, it's bad. I found this through searching TGO : http://store.summitracing.com/partde...5&autoview=sku

Apparently the stock pulley has a diamter of 1.9xx and this is 1.6xx. My volts never exceed 13 and supposedly people said with this they're at about 14 constant. Anyone ever do this?

Put your stock pulley on it.

You got a normal alt right, not a 1-wire?

It's a single connector alternator, same as stock. I had this alternator on my 92 RS years ago and I never had a problem, but on the iroc I have a problem. The pulley is the same size as stock.

Single connector or single wire? Stock has a connector with 2 or 3 wires and a battery lead to a stud on the alt.

Are all your pullies stock sized?

If the pullies are stock sized and the wiring is the same I'd be apt to lay blame on the alternator -either bad or incorrect application. You should not have to change pulley sizes from stock.

put a meter on it just to be sure. Can't always trust the gauge

yeah but if his headlights are dimming and such i would assume the gauge is fairly accurate. take it to a shop and let them test the charging system. see if the alternator is keeping up. check the power wire for corrosion or a loose connection on either end too.

guess i should have read his post .. lol

It's a two wire plug. It also has the wire going from the stud to the battery. I've had the alternator tested and it came out fine, I was also given a new alternator to try and I had the same results. All the pulleys are stock. What I read on TGO was that the higher amp alternators produce the power during higher RPM's and a smaller pulley is needed to compensate for idle. What's weird to me is I had this alternator on my RS and I had a monsterous stereo system in it and I never had a problem with my volts dropping. In the iroc, I can be at a light with my lights on, brakes on, and a turn signal-the headlights go dim and my turn signal barely blinks...without the radio on or any other accesaories :lol:

battery good? maybe a cell went bad and it can't compensate for the load all those accessories are putting on it. if the alternator tested good i would still have a shop throw an amp meter on it in the car to see what it puts out at idle. that and load test the battery

I put a new battery in it a couple of months ago. I have the equipment to datalog it, but I have to see why my ALDL isn't connecting to the ECM first before I can datalog.

are your fans running at all? did you upgrade to heavier gauge cable from the alternator to the battery that they provided in the kit? are all your terminals tight/clean? i have this same alternator and dont have any problems with it powering all my power stuff. My Ron Davis radiator fan setup sure puts a load on it and at idle i will dip to abotu 13 with them on, other then that 14.2 v all the way

ted you are stumping me. didn't you just do head gaskets on your car? break/forget a ground wire? hopefully you can pull the data so i can grind my teeth wondering whats up with it.

I didn't get a kit, it was just the alternator, but I did do the "big 3" upgrade not too long ago. One fan is on all the time but even with it off I still have the same behavior.

One thing I've noticed on other cars is a seperate ground coming off the alternator casing to the strut tower-mine never had that. Also, with the voltmeter on the battery when the car is running it's reading around 14.3. I did the header gaskets this past weekend, not head gaskets.

So this alt tested good, and another known good alt was installed and it did the same thing? I might say that eliminates the alt as an issue. And all pullies are OE (no underdrive crank or anything).

You have no reason to datalog for this issue, but I can't help but wonder if there is a connection between this issue and the ALDL failure.

What is 'the big 3'? Why is one fan on all the time?

I was thinking datalog because it would give me the volts from connecting through the ALDL. The big 3 is upgrading the wire to a heavier guage from the 1. alternator positive to battery 2. battery ground to chassis 3. engine ground to chassis

edit: the fan is on because I wired it to run all the time to keep the car running cooler. All I did was ground the switch on the passenger side head.

It's off topic but you should let your fans run properly. If it is too cool your car will stay in open loop. The ECM expects a certain temp range.

Did you make those new wires or was it a kit? Check all the terminals are tight/properly crimped, clean & properly secured. Grounds have star washers. This is gonna be something stupid, just watch.

I think all that was tuned out, I told josh I had the fan running constantly.

I made the new wires and I made sure everything was done properly.(rechecked connections, cleaned grounds etc) It's gotta be something from the battery to inside the car because I'm getting the correct volts at the battery when the car is running.

Did you upgrade your headlight harness when you did the H4 conversion? If the only symptoms you are seeing are exterior lights dimming, it could be due to a bad wire / connection in the light harness.

Try turning on the dome light in the car and see if it also dims with the headlights and turn signal on at idle.

- Justin

I upgraded the headlight harness with relays and things (painless kit) and everything dims, power windows slow up etc. It actually seems to almost stall out the car if I have too many things running without getting the rpm's up, so it's definitely a major component to the electrical system and not just one aspect of the entire system.

-Ted

Your alt is not charging the car.
Battery has nothing to do with it.
Do you have any underdrive pullies on the car? Not just the alt, but crank, wp, anything that would slow down the rotation of the alt?
My 87 still has a underdrive pulley on the crank, and at night the blinker is slow and guage drops down to 13 volts.
I would take it to a shop so they can put a load test on the alt with it in the car, not just the alt itself.
Is it better durring the day time, with no electrical equpment on or is it the same?

No underdrive pullies on anything and the air pump no longer exists. As long as the rpm's are up, day or night, I never have anything above 12/13 volts. It's just that the more accessories I have on (more so at night) the lower my volts drop at idle. Even with the new alternator I had to try out, I still had the same problems, so I have no idea. I guess the next thing to do is trace back my wires from the ALDL and maybe I'll uncover something under the dash. I know the previous owner had a lot of things rewired under there...which is probably the problem.

Does everything electrical otherwise work?

yup

Deffinatly look at some wiring.

i have the same issue ted. the one thing that sticks out is that i also have a powermaster alternator. i think i might revert back to my stock alternator and see if that fixes it. if thats it, i'm going to find mister powermaster and punch him in the face for us