Author Topic: Alt Question  (Read 2116 times)

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Offline grumpygy

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Alt Question
« on: December 02, 2011, 07:06:30 PM »
  I've got the 160  Alt from E-bay.  Been working fine this summer.  But this morning I noticed a problem.  At Idle I had on Headlights, Fog Lights(which are HID) and the heater fan.   Noticed that the voltage was reading low about 8.

  Gave it some gas and went right back to around 14 and stayed there, but I did not sit at Idle any length of time.  Also have not changed the wiring to hand the addition amps, its still stock.
94 YJ, Cool Air intake, 19lb Inj, 4.0 Throttlebody with spacer,  31/10.50/15's

Offline sharpxmen

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Re: Alt Question
« Reply #1 on: December 02, 2011, 09:07:07 PM »
  I've got the 160  Alt from E-bay.  Been working fine this summer.  But this morning I noticed a problem.  At Idle I had on Headlights, Fog Lights(which are HID) and the heater fan.   Noticed that the voltage was reading low about 8.

  Gave it some gas and went right back to around 14 and stayed there, but I did not sit at Idle any length of time.  Also have not changed the wiring to hand the addition amps, its still stock.

if it was around 8v (and it was not your voltmeter acting up) it means it was not charging, since you got back to normal voltage it was not  b/c of the fuses, reasons can be excitation voltage from PCM, stuck brush inside the alternator or bad contact at the control wire going to the alternator. Could also be the main power wire from alternator but i doubt it (if it's loose and was not making contact, easy to check). Keep an eye on it, hard to tell now since it works.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline grumpygy

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Re: Alt Question
« Reply #2 on: December 02, 2011, 11:09:18 PM »
Could it be that the Alt Does not put out that well at low RPM was at about 800 rpm when this happened.  This is also the 1st time I've run these fog lights.
94 YJ, Cool Air intake, 19lb Inj, 4.0 Throttlebody with spacer,  31/10.50/15's

Torch_Ind

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Re: Alt Question
« Reply #3 on: December 03, 2011, 08:27:58 AM »
Could it be that the Alt Does not put out that well at low RPM was at about 800 rpm when this happened.  This is also the 1st time I've run these fog lights.

depends if your near the max output of the alt at idle before you put your lights on otherwise it's like sharp says or your belt was slipping

Offline sharpxmen

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Re: Alt Question
« Reply #4 on: December 03, 2011, 08:32:07 AM »
Could it be that the Alt Does not put out that well at low RPM was at about 800 rpm when this happened.  This is also the 1st time I've run these fog lights.

if the fog lights are 100w, that makes it 200 total, at 12v that's something like 16.5 amps, shouldn't go down to 8v.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

reddogg

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Re: Alt Question
« Reply #5 on: December 03, 2011, 11:01:07 AM »
I have the 160amp alt. I used my winch, it pulls 100amps according to the winch info. My alt drops down to like 12V for a second then picks back up to 14v running at idle speed. if your belts is not slipping then I would be getting the alt checked out somewhere.

Offline grumpygy

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Re: Alt Question
« Reply #6 on: December 03, 2011, 11:48:16 AM »
THanks thats what I wanted to know.
94 YJ, Cool Air intake, 19lb Inj, 4.0 Throttlebody with spacer,  31/10.50/15's

Offline jfrabat

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Re: Alt Question
« Reply #7 on: December 04, 2011, 04:03:27 PM »
Check with a voltmeter...  Probably your gauge is acting up, mot yor alternator.  I know this is the case in my Jeep, at least...
'94 YJ 2.5L with 4" RE lift, Superwinch EPi9.0, FoMoCo e-Fan, SD30 and SD35 w/ARB-5.13, 165A alt., 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Hydroboost

Offline grumpygy

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Re: Alt Question
« Reply #8 on: December 04, 2011, 04:50:15 PM »
Not the gauge as I heard the fan drop RPM when I turned on the fog lights.  It did slip a little as that happened so may need to tighten the belt.
94 YJ, Cool Air intake, 19lb Inj, 4.0 Throttlebody with spacer,  31/10.50/15's

Offline dwtaylorpdx

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Re: Alt Question
« Reply #9 on: December 04, 2011, 09:39:58 PM »
The dash voltmeter in the YJ at least is no more than a idiot light. Mine drops when I turn on the heater, the radio the headlights etc and I have checked it with a hand meter and its always OK...

Dave
94 YJ - 2.5 Hesco Cam B&B Ported - AX5 Trans w/Centerforce Dual Friction Clutch - 4" Rough Country Lift W/Skyjacker Shocks - D44 Rear/ARB - D30/ARB - ARB Compressor - Warn M8000 in Custom Bumper - Reunell Rear Bumper - Metalcloak 6" Body Armor Kit - Tuffy Console - 265x85-16 Tires - 2M Radio

Offline jfrabat

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Re: Alt Question
« Reply #10 on: December 05, 2011, 11:44:08 AM »
The dash voltmeter in the YJ at least is no more than a idiot light. Mine drops when I turn on the heater, the radio the headlights etc and I have checked it with a hand meter and its always OK...

Dave

Mine drops to 10V when I turn on the AC.  I have checked it with a Voltmeter, and it's fine, though. 

Not the gauge as I heard the fan drop RPM when I turned on the fog lights.  It did slip a little as that happened so may need to tighten the belt.

I can run my stereo (I run an amp), GPS, both radios (CB and 2m), headlights, 50W foglights and 100W driving lights without issues with my 164A (or so; dont remember the exact number) at idle.  Of course, my Jeep idles at 1,000 RPM, not 800 RPM, and that can make quite a bit of difference for the alternator...
'94 YJ 2.5L with 4" RE lift, Superwinch EPi9.0, FoMoCo e-Fan, SD30 and SD35 w/ARB-5.13, 165A alt., 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Hydroboost

Offline sharpxmen

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Re: Alt Question
« Reply #11 on: December 05, 2011, 03:24:05 PM »
Mine drops to 10V when I turn on the AC.  I have checked it with a Voltmeter, and it's fine, though. 

I can run my stereo (I run an amp), GPS, both radios (CB and 2m), headlights, 50W foglights and 100W driving lights without issues with my 164A (or so; dont remember the exact number) at idle.  Of course, my Jeep idles at 1,000 RPM, not 800 RPM, and that can make quite a bit of difference for the alternator...

why does your Jeep idle at 1000rpm?
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Torch_Ind

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Re: Alt Question
« Reply #12 on: December 05, 2011, 05:06:23 PM »
The dash voltmeter in the YJ at least is no more than a idiot light. Mine drops when I turn on the heater, the radio the headlights etc and I have checked it with a hand meter and its always OK...

Dave

mine in my yj is always in the red saying it's over charging but I have tested it with a meter and it's 14-15v and I even ran a tester on it at work and it passed.  it will drop down to 8v when using my winch to but I put a meter on it and it doesn't really drop lower then 10-12v.. I just ruled it out as my gauge isn't accurate so it doesn't bug me anymore.

Offline dwtaylorpdx

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Re: Alt Question
« Reply #13 on: December 06, 2011, 01:43:09 PM »
I think its related to the itty bitty wires they use under the dash to run the gauge too much voltage drop in the harness?

Dave
94 YJ - 2.5 Hesco Cam B&B Ported - AX5 Trans w/Centerforce Dual Friction Clutch - 4" Rough Country Lift W/Skyjacker Shocks - D44 Rear/ARB - D30/ARB - ARB Compressor - Warn M8000 in Custom Bumper - Reunell Rear Bumper - Metalcloak 6" Body Armor Kit - Tuffy Console - 265x85-16 Tires - 2M Radio

Offline chardrc

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Re: Alt Question
« Reply #14 on: December 06, 2011, 01:56:31 PM »
my voltage gauge goes up and down with the blinkers... I'm not too trusting of it.
1990 YJ 4cly, ax5, 2.5 inch BDS lift, 31 MTr\'s,  Powertrax-lockers all around, track-bars removed, boomerang shackles, warn m8000 winch, electric fan. [sold but not forgotten]

2007 jk Rubicon 2dr