Alternator quesrion
Thread Starter
Intermediate
Joined: Aug 2014
Posts: 33
Likes: 2
Alternator quesrion
I've been getting intermittent "Service Electrical System" messages in my 07 C6Z. Weekend, fair weather car (HCI). I haven't noticed any voltage drops, but I'm considering an alternator replacement/upgrade.
What's everyone's opinions about Mechman versus J&S alternators? Any other manufacturers recommended? Read mixed reviews about Mechman, but they're the most popular. Is a 240 Amp unit the way to go if I anticipate radiator and/or fan upgrades in the future? Finally, is the Big 3 wiring upgrade recommended as well? Seems like a worthwhile upgrade to go with the higher Amp unit.
What's everyone's opinions about Mechman versus J&S alternators? Any other manufacturers recommended? Read mixed reviews about Mechman, but they're the most popular. Is a 240 Amp unit the way to go if I anticipate radiator and/or fan upgrades in the future? Finally, is the Big 3 wiring upgrade recommended as well? Seems like a worthwhile upgrade to go with the higher Amp unit.
Drifting
Joined: Jul 2011
Posts: 1,821
Likes: 442
From: Boca Raton Florida
Do not install 240 amp unless you have high demand in the way of a killer stereo. Rad or fans do not require that much. 170 is the best, on 240 it will not charge during idle, you have to bump it up.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,500
Likes: 3,999
From: Cape Coral, Florida
The FIRST thing you want to do is scan for any codes and then have your battery checked…if electrical circuit testing is over your head find an auto electric shop in your area…no need to go to a bigger alternator or even this “big three “ wiring upgrade…if all the battery and alternator connections are clean and tight the alternator should be doing its job at all operating conditions.
Thread Starter
Intermediate
Joined: Aug 2014
Posts: 33
Likes: 2
J&S stated my 850 rpm idle would be sufficient to get full charge. Thanks for the reply.
Instructor
Joined: Mar 2019
Posts: 168
Likes: 53
From: Mooresville, IN
i recently purchased and installed a Mechman 170A alternator with great results. I have an '08 C6M with 47k miles...
I was having intermittent charging issues with the stock alternator. I was going down the interstate and voltage would be normal, then suddenly drop to below 12 volts for a bit, then jump up to12.8, then down, then up to 13.4 or so.... then back down below 12V. I checked and verified all connections were secure at the battery, alternator, and starter. Looked over all visible wiring in, around, and under the engine bay area and all looked A-OK. After a bit of research, it appears the stock alternator is not up to the task to supply adequate charging capacity in many instances. I believe it was intermittent and perhaps had internal issues, so I upgraded to the Mechman and couldn't be happier. I now have a consistent 14.6 to 14.8 volts regardless of load.
Also, when I contacted their tech line for advice on the best option for me, and then went on their website to order, I got an additional 10% off for using their tech line !!! AND... the black unit I bought looks great under the hood.... an added bonus.
I was having intermittent charging issues with the stock alternator. I was going down the interstate and voltage would be normal, then suddenly drop to below 12 volts for a bit, then jump up to12.8, then down, then up to 13.4 or so.... then back down below 12V. I checked and verified all connections were secure at the battery, alternator, and starter. Looked over all visible wiring in, around, and under the engine bay area and all looked A-OK. After a bit of research, it appears the stock alternator is not up to the task to supply adequate charging capacity in many instances. I believe it was intermittent and perhaps had internal issues, so I upgraded to the Mechman and couldn't be happier. I now have a consistent 14.6 to 14.8 volts regardless of load.
Also, when I contacted their tech line for advice on the best option for me, and then went on their website to order, I got an additional 10% off for using their tech line !!! AND... the black unit I bought looks great under the hood.... an added bonus.
Intermediate
Joined: Jul 2020
Posts: 49
Likes: 10
From: CA
I had similar problem volts will go up and down, Went through 3 alternators got one rebuild from local shop for 250amp that one ran ok for few days then same problem. Went to Autozone got duralas gold while puttting it on I started checking wires and found out the 3 wires goes on top of Alternator were melting inside black heatshield tape and kinda glued together. Got another pigtail wire connector and replaced it . Never had issue again. I think too much heat from LT headers.
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