Mechman Alternator Help

[TRMN8R55]

I could use some advice about my cars alternator. I put a 4 lb lower on my car about a year ago, naturally even with the metro 3.2 inch pulley the stocker went out on me. Bought a Napa alternator put the same pulley on it and it lasted maybe 100 miles. I then ordered a Mechman alternator and the person over the phone told me he was going to it to me with a 2.6 inch pulley on it. I put it on my car about a month ago and have been going through different belt sizes to try to get it to fit. The belt I have on there now is a 77.2 inch Gatorback (now known as Continental) and that thing is tight on there. The car idles fine and the volts show around 14.3 to 14.4 ish. Now when I go WOT the battery light will flicker and the voltage bounces around the mid 13s. I have been through about 6 belts both Gates and Gatorback to try and figure this out and it is driving me nuts. Boost seems to be reading like it used to exert I can't find the dyne sheet for some reason to see how my boost dropped before but it seems the same. So I guess my question is do I have the right pulley on there for an 4 lb lower? Should I put to Metco 3.2 on there and see how it does? Also what voltage does the battery light turn on at and what should it be at WOT (I would assume somewhere around 14). Thank you in advance for the help and sorry for the long read!

 

[TRMN8R55]

bump

 

[whitedevil95]

Not sure what the issue is. I have a Mechman on the way but i have a stock lower pulley.

 

[Oiljunkie]

Put the 3.2 pulley back on

 

[BoostedByV]

No lower here but I'll would send it in because that flicker means faulty alternator

 

[TRMN8R55]

I don't think the alternator is failing if it doesn't drop voltage lower than 13.2v. I think I will get it up on a lift and check the wiring and maybe put the bigger pulley on. The larger pulley won't affect the alternator will it? I know for the stock ones it helps slow them down but being that it is a Mechman I don't know if that makes a difference.

 

[Coxy]

You have a wiring problem. If you're still seeing in the 13.x volts, you're a long ways from a legitimate battery light. I'd still run the larger pulley on the alt, it's still being spun much faster with the lower.

 

[CobraBob]

I'm wondering why Mechman sent you a 2.6 pulley to replace the 3.4. Did they know you have a 4lb. lower? I would call them and ask why they wanted you to install 2.6 pulley.

 

[AMB]

Mechman Alternators take a SPECIAL PULLEY. You can't just put a STOCK/AFTERMART pulley on it!!! I believe the 2.6" pulley is there stock pulley, to get the correct current at idle!!!

 

[Oiljunkie]

Idle and WOT alternator RPM's will be a lot different with a 4# lower. I don't see how the 2.6 is correct over a 3.2 with the 4# lower.

 

[TRMN8R55]

I'm wondering why Mechman sent you a 2.6 pulley to replace the 3.4. Did they know you have a 4lb. lower? I would call them and ask why they wanted you to install 2.6 pulley.

I told them that I had a 4 lb lower and they were between giving me the 2.6 or the 2.9 pulley they have. I don't know what there determining factor to giving me the 2.6 was.

 

[bubblehead93]

just bought a mechman, I have a 4# lower, they quoted and shipped me the 2.9, told them it was a auto-x, road, and drag car... perhaps as a daily driver/cruiser they lean towards the 2.6 and for folks who might live at 5-6.5k rpm for sustained periods the 2.9...

I would just ask them, the 2.9 pulley was $15-20, I'm sure they can explain what their thought process was... they have been very responsive via email in all of my dealings...

r/
Andy

 

[TRMN8R55]

Ok I will have to give them a call first thing in the morning then. Maybe they didn't understand how I drive my "street car"

 

[TRMN8R55]

Ok so I was finally able to call them today, excellent customer service btw. Apparently I had given them the wrong dimensions of the crank pulley and the 2.6 was incorrect. They are sending me out a 2.75 pulley to try out since they can't get a 2.9 pulley for a while and are out of stock. Should have it by Thursday and will update as soon as I can get it on the car!

 

[sonic cobra]

I agree, you have a wiring problem to the battery light. When I installed my mechman I was getting battery light but was still charging 14+ volts. Just fine in the driveway but light flickered on the highway. Mechman wanted me to send it back, but i found a loose wire going into their plastic connector. Once I taped that sucker up securely and ziptied that connector to something so it couldn't move around in the airstream, I had no more problems with the battery light.

 

[TRMN8R55]

Ok I forgot to update this but the 2.75 in pulley works great. No battery light and holds Volts in the 14s throughout the power band. Thank you everyone for your help!