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james5275
11-03-2016, 10:25 PM
Hello everyone,
Video here: http://youtu.be/suEWlGVov4c

I purchased a 6g alternator from a reputable source on eBay, having issues.

The seller is well known to the mustang community, he offered his advice and help, even sent another regulator at no charge. I swear it's an alternator issue, please read on....

My OEM alternator worked fine until about 10 years ago, I replaced the regulator with an autozone regulator and had no issues until recently, she just quit charging. Diagnosis, no output, regulator likely failed again.

I bought the 6g cobra mustang 160 amp, bolts right in, only minor change is the plug. Immediately after installing, I noticed the voltage was awful jumpy. Charges just fine when the system is stabilized, but if you add a load such as cooling fan, it sends the voltage into a series of surges. At times, it peaks near 17 volts and the the computer cuts off ignition. During cruise is more stable, but when it does surge and ignition cuts off, it jerks the car pretty bad. Similar symptoms to a cutting out DIS, which I have experienced in previous years.

Has anybody seen this with the newer 6g? I've spent countless hours googling all of the possible tech help and regulators, have now tried 3 different styles with no luck, all respond the same.

Seller recommended fresh battery as well as new cables and grounds, battery terminals, numerous engine grounds, ecm ground,which ofcourse I have done, to no avail. The key I have noticed, it doesn't spike when the load is applied, it spikes when the load diminishes, AKA "load dump".

Anybody willing to try this alternator in their car? I'll pay shipping. I'm at my wits end wondering if I'm doing something wrong or if the issue is actually something else with my 90 auto.

Idle voltage in gear is the normal 14.2-14.4 ish when stabilized, I believe she's spinning plenty fast at idle even with the larger pulley than the sc. The engine drops rpm just like normal when the load kicks in, so the alternator is responding to the loads, just seems to overcompensate when the load dissipates.

Ofcourse when I disable the alternator and run off the battery, all of the cutting out symptoms disappear.

Item specifics
Condition: New Brand:
Hi-Tech
Warranty: Yes Manufacturer Part Number:
8304
Country/Region of Manufacture: United States Interchange Part Number: replaces# GL-555, GL-616
Core Charge: NO Core Charge Other Part Number: replaces GL-555, GL-616
Part Brand: aftermarket Surface Finish: FORD:
UPC:
076783016996

Any other thoughts or ideas?

Thanks,

JJ

89XR7TD
11-04-2016, 12:46 AM
Hello everyone,
I purchased a 6g alternator from a reputable source on eBay, having issues.

The seller is well known to the mustang community, he offered his advice and help, even sent another regulator at no charge. I swear it's an alternator issue, please read on....

My OEM alternator worked fine until about 10 years ago, I replaced the regulator with an autozone regulator and had no issues until recently, she just quit charging. Diagnosis, no output, regulator likely failed again.

I bought the 6g cobra mustang 160 amp, bolts right in, only minor change is the plug. Immediately after installing, I noticed the voltage was awful jumpy. Charges just fine when the system is stabilized, but if you add a load such as cooling fan, it sends the voltage into a series of surges. At times, it peaks near 17 volts and the the computer cuts off ignition. During cruise is more stable, but when it does surge and ignition cuts off, it jerks the car pretty bad. Similar symptoms to a cutting out DIS, which I have experienced in previous years.

Has anybody seen this with the newer 6g? I've spent countless hours googling all of the possible tech help and regulators, have now tried 3 different styles with no luck, all respond the same.

Seller recommended fresh battery as well as new cables and grounds, battery terminals, numerous engine grounds, ecm ground,which ofcourse I have done, to no avail. The key I have noticed, it doesn't spike when the load is applied, it spikes when the load diminishes, AKA "load dump".

Anybody willing to try this alternator in their car? I'll pay shipping. I'm at my wits end wondering if I'm doing something wrong or if the issue is actually something else with my 90 auto.

Idle voltage in gear is the normal 14.2-14.4 ish when stabilized, I believe she's spinning plenty fast at idle even with the larger pulley than the sc. The engine drops rpm just like normal when the load kicks in, so the alternator is responding to the loads, just seems to overcompensate when the load dissipates.

Ofcourse when I disable the alternator and run off the battery, all of the cutting out symptoms disappear.

Item specifics
Condition: New Brand:
Hi-Tech
Warranty: Yes Manufacturer Part Number:
8304
Country/Region of Manufacture: United States Interchange Part Number: replaces# GL-555, GL-616
Core Charge: NO Core Charge Other Part Number: replaces GL-555, GL-616
Part Brand: aftermarket Surface Finish: FORD:
UPC:
076783016996

Any other thoughts or ideas?

Thanks,

JJ

When I did the 6G conversion, I always had to rev my motor up after starting it and then the volts would stay up to 13.8-14.00's you probably have to do that also...just rev it to 3,000 rpm or so and see what happens.

james5275
11-04-2016, 01:28 PM
With the regulator that came in the 6g, as long as the sample wire is connected to the alternator, no revving is needed. Comes online just as normal. (Small gauge yellow, fusable link protected). If I left that wire disconnected yes, revving the engine would make it come alive, but the voltage spikes would actually increase, as well as normal output.

With yellow disconnected, voltage would increase to about 14.9 volts.

Regulators I have tried all made by Transpo, F606, F605 (both designed for PCM control)

F600 is installed now, supposed to be a standard, early model 6g, old school style regulator, but the voltage spikes still remain. Only different behavior with the F600 is the alternator will not energize at all with the sample wire disconnected.

Most of my online research has revealed power or ground issues. Cant be the issue this time.

Last week for giggles, I reinstalled my original OEM SC alternator, of course it only lasted for about 5 minutes but while charging the voltage response to load was completely normal. No jumping, nice and steady.....but then it failed again.

Hate to spend another $80 for a OEM (autozone) regulator but may have to. I'll post a video tonight.

JJ

KMT
11-04-2016, 01:46 PM
Sorry if I missed it - do you have any aftermarket volt/amp gauges installed in the car?

sam jones
11-04-2016, 02:49 PM
Good morning


You might want to take the alternator to your local and trusted electrical shop to have it check out. Although I have no experience with 6G units, rebuilt units from the discount stores in a word is a "mess". I worked on a 2003 Focus 2.0 L dohc that failed three Auto Zone alternator units within six months. The fourth unit I bought at the local salvage yard. Before install had it checked out at my electrical shop. Was told this was not unusual for a store unit to fail so soon as volume over quality is norm. Salvage unit was inspected, parts replaced and installed on the Focus with no alternator issues.



Good Luck

KMT
11-04-2016, 03:53 PM
Note that the biggest reason store units fail on our cars is that they are installed (despite boxed warnings) against a dead/depleted battery. The owner then somehow gets the car started and relies on the alternator to bring the battery back to life and it fails. They go back to the store for another (bad rebuild!), wash/rinse/repeat, then blame the quality and the process (store units always bad!), by that time the battery is charged up and surprise... a used alternator works fine and gets applauded, while all along they ignored the process and the rebuilt alternator(s) never had a chance.

On the SC, never use the alternator to charge a dead battery. Use a battery charger instead. Your newly rebuilt alternator will thank you.

Ken

james5275
11-04-2016, 08:22 PM
YouTube video here.....first time uploading hopefully it works.

Seller ofcourse mentioned the weak battery. Original battery held about 12.4 volts, he swore up and down it needed to be at least 12.5-12.7. Weak original battery issue possible I suppose. It was very healthy when cranking the engine through. I did top it off before installing the 6g.

http://youtu.be/suEWlGVov4c

KMT
11-04-2016, 09:01 PM
I did top it off before installing the 6g.



I was more defending store rebuilds ;), rather than questioning your process, but still a good data point for your issue(s), thanks.

What about other gauges?

james5275
11-04-2016, 11:20 PM
For gauges, voltmeter, electric fuel pressure, aftermarket vac/boost. The reason I installed the voltmeter was because of my alternator issues 10 years ago.

Voltmeter is from Speedhut. It has a gear drive for the needle which is inherently slow to react. Maybe I'll post another vid with an old school standard voltmeter, then you can really see how much the voltage changes.

J dot Miller
11-05-2016, 07:24 AM
I went with the 3G, required a little grinding but works great. I get all my alternators at PA Performance.

These cars are old and the ground wires should be checked or replaced. Here is a link from a previous 6G install here: Rickbtbird 6G install (http://www.sccoa.com/forums/showpost.php?p=730337&postcount=8)

james5275
11-05-2016, 06:33 PM
Yeah, wondering if I should have gone the 3G route. Here's another video with a standard voltmeter.

http://youtu.be/CxcKwXjdHYE

You can see here it easily indicates 16 volts, I've seen as high as 17+ on my dvom.

A few more details, I compared my voltage readings with several other cars of all different types- Mercedes, Chevy new and old, other fords, none of them have the fast jumping. They're all nice and steady when electrical load is applied, which I would think is normal. Seems like this 6G is on crack.

JJ

KMT
11-05-2016, 07:05 PM
Huh - don't think I've _ever_ seen that. The regulator seems out to lunch if you ask me. Gets some heat in it and up/down/up. But then you said a stock alternator repeatedly dies a short term horrible death, so... Very strange.

You haven't had that alternator apart?

james5275
11-08-2016, 06:53 PM
Spoke with several alternator repair shops, couple electrical engineers, shared the videos, best advice so far is battery terminals. Sounds like nobody really knows exactly how a solid state regulator functions. I did more work with the trusty search function and found a few other posts under "surging/bucking".

1. I noticed there was a round of alternator failures in the early 2000's
2. Mid-Late 2000's the surging/bucking posts came around. A couple people replaced every sensor, dis, coil pack, etc with no luck, or didn't post back the fix.

Based on description, mine fits into surging issue. Bear in mind, a voltmeter isn't factory equipment. If I didn't already have one installed, I would also probably be chasing my tail.

I reinstalled my oem Mitsubishi regulator in my original alternator today, hoping to get lucky enough that it works for 10 minutes, enough to verify alternator is the issue. I'll report findings.

JJ

james5275
11-12-2016, 02:56 AM
Update,
Reinstalled original alternator with original regulator, not the best luck. Still only charges at about 13 volts, not a great comparison. No surging. Listed 160 amp on CL, will look for a replacement in the meantime.

james5275
11-15-2016, 12:33 AM
Wandered through the local junkyard yesterday, low and behold a late model v6 bird was there, with a shiny, new, reman alternator. I figured for $20 I couldn't go wrong.

Spent about 30 minutes grinding away my alternator bracket, thinking about removing material from the alternator to possibly allow the top bolt to fit. Removed the 6 rib and installed the cobra 8 rib pulley.

For testing, close enough. Dropped it in, slapped on the belt, fired it up, flawless. Provides plenty of juice, rock solid 14.7 at idle, in gear, fans running. And this is with a larger than stock pulley. Not quite the diameter as the aluminum overdrives, probably half way between OE and full on overdrive.

No more cutting out!!!

Strongly suggest for anyone experiencing an intermittent cutout situation to check your charging system for voltage fluctuations! Post pics tomorrow.

JJ

james5275
11-15-2016, 08:54 PM
Video below. Amazing difference. Unfortunately I don't know exactly what the output rating is of this 3G, looking at my voltmeter it handles the loads just fine.

https://m.youtube.com/watch?v=enVBDY-RlIs&itct=CBAQpDAYAiITCK-0_ZWHrNACFcGmTgodmKYD3DIGcmVsbWZ1SIf_oqvG0sXwsgE%3 D

We'll see next spring how it does at the drag strip.

JJ

KMT
11-15-2016, 09:55 PM
Thanks for the followup - fingers crossed ;)

Ken