Dual Fans, upgraded alternator, still not enough charging ..

1993SSP

Founding Member
Sep 5, 2001
1,194
0
37
Ky
Visit site
I'm needing some tech help. I put a newer style, from the junk yard alternator on a fox body 5.0 for a guy. The reason for adding this is because he had upgraded to an aluminum radiator and dual electric fans. I upgraded all the wiring as needed for the new alternator with 4ga wire and a 140 amp breaker. He drove the car abour 25 miles round trip, got back home, shut off the car and it will not start back, he told me the amp guage would barely stay just above red. The paperwork with the fans stated they are 20 amp each. He has the fans wired on a relay and they run all the time. Any suggestions??
 
  • Sponsors(?)


HISSIN50

"How long does it take to get help in here?
SN Certified Technician
Nov 29, 1999
31,179
28
129
Take a volt reading of the system, noting if the alternator has any output.
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,395
2,845
234
74
Dublin GA
lowendmac.com
Also make sure that the 4 gauge ground was added.
Any car that has a 3G or high output current alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.
The 3G has a 130 amp capacity, so you wire the power side with 4 gauge wire. It stands to reason that the ground side handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & alternator

Picture courtesy timewarped1972
ground.jpg
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,395
2,845
234
74
Dublin GA
lowendmac.com
What should the volt reading be at the battery while the car is running? 13-14volts dc??
You should see 13.8-14.2 volts at idle. That range insures that the battery will charge properly. Most common is in the range of 14-14.5 volts at 1000 RPM.
 

montegoman351

Member
Jan 12, 2007
169
1
18
I'd say check the ground issue...get the car started...run it to Autozone, etc., and have them hook up the machine to it. I put a 130A alt on the Montego a while back, then I took the car down to Autozone and had them test it...it tested out 110A...as long as it's putting out at least 80% of it's advertized amperage...it's good...:nice:

Are you running underdrives? If so, that could hinder the charging system...:nonono:
 

LiquidGT

Member
Oct 8, 2007
368
0
16
38
Near STL hell
Do you know what the alternator came out of?

Oh yeah, did you not use the stock wiring at all with the new 4ga wire? One of the regulator wires is hidden in the stock alt harness.
 

faststang90

10 Year Member
Nov 5, 2007
522
12
49
baytown texas
pulley on alt

i changed my over to 130 off a newer car dont remember what year (94-95) i think it was but it would not charge the batt. i was looking at the new alt and my old one and the newer one had a bigger pulley on it and the old one was smaller but the older one has a fan on the out side. so i took the pulley of the old one and installed it on the newer one. just check the pulley size
 

1993SSP

Founding Member
Sep 5, 2001
1,194
0
37
Ky
Visit site
Do you know what the alternator came out of?

Oh yeah, did you not use the stock wiring at all with the new 4ga wire? One of the regulator wires is hidden in the stock alt harness.

I plugged the stock harness into the new alternator, I then spliced the blk/white on the new sty alternator onto the blk/white on the original harness
 

LiquidGT

Member
Oct 8, 2007
368
0
16
38
Near STL hell
Maybe heck the circuit breaker? I had a resettable (type III, I think) breaker in my car, it worked fine on the cooler days/months, but on really hot days the combined heat from the ambient air and engine would trip the breaker and its wouldnt reset until it cooled down. Now I'm using a fuse, it probably not the problem you're experiencing, but I'm just throwing that out there.
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,395
2,845
234
74
Dublin GA
lowendmac.com
Do not use the stock wiring on a high current alternator. You are risking an electrical fire. The only exception is the SSP police/highway patrol vechicles that came witha a high current alternator and different wiring.

See the Stangnet 3G install sticky 3G Alternator Install: A How To - Mustang Forums at StangNet for proper wiring for a 3G or other high current alternator installation.
 

lang williams

New Member
Jun 11, 2003
567
0
0
55
cleveland, oh
Visit site
I graped a 3g out of a 94 T bird for my project 84...The stator wire on the alt plug was cut off an nothing connected to it. Can this be done? Is there a way to trick the alt. The black/white wire isn't even on my harness. Whats on the other end? I may have to run one to where ever it goes. FYI the car is a 84 with a 87 dash 4 cyl 5.0 conversion.
 

HISSIN50

"How long does it take to get help in here?
SN Certified Technician
Nov 29, 1999
31,179
28
129
I graped a 3g out of a 94 T bird for my project 84...The stator wire on the alt plug was cut off an nothing connected to it. Can this be done? Is there a way to trick the alt. The black/white wire isn't even on my harness. Whats on the other end? I may have to run one to where ever it goes. FYI the car is a 84 with a 87 dash 4 cyl 5.0 conversion.
The stator loops from the S terminal on the regulator to the lone terminal on the 3G body. You don't need to use any OEM body harnesses for the stator circuit.
 

lang williams

New Member
Jun 11, 2003
567
0
0
55
cleveland, oh
Visit site
Thanks for the info hissin but I'm not following it. what is the s terminal? guess I just need to know what to do to make my own stator connection. I looked at the auto zone wiring diagrams an didn't see it. I didn't mean to jack this thread, but thanks for the info.
 

HISSIN50

"How long does it take to get help in here?
SN Certified Technician
Nov 29, 1999
31,179
28
129
Thanks for the info hissin but I'm not following it. what is the s terminal? guess I just need to know what to do to make my own stator connection. I looked at the auto zone wiring diagrams an didn't see it. I didn't mean to jack this thread, but thanks for the info.
PM sent.
 
Thread starter Similar threads Forum Replies Date
M Ford Contour/Mercury Cougar Dual Fans Other Auto Tech 1
L SVE DUAL FANS 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 33
G Dual fan/relay question Fox 5.0 Mustang Tech 4
B Mishimoto Dual Fans On And Off 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 9
A How To Install Overflow With Dual Fan Set Up? Fox 5.0 Mustang Tech 3
Gearbanger 101 Anyone Hook Up A Dcc 2sp Controller To Dual Fans? Fox 5.0 Mustang Tech 3
A Contour Fan Wiring- Dual Speed Knowledge Fox 5.0 Mustang Tech 11
larrym1961 $45.75 Ebay Contour/mystique Electric Dual Fan Out Cools $375 Flex-a-lite Extreme Puller! 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 11
N Dual Thread Meziere Wp111b, And Elec Fan. Fox 5.0 Mustang Tech 0
J Dual Contour Fans Fox 5.0 Mustang Tech 10
SitDown NIB - Flex A Lite 410 Dual Fan - 2 5/8" Thick Engine and Power Adder 1
6 New Dual Spal Fans for 67-68 stang Engine and Power Adder 0
2badazzstangs Saleen Dual Electric Fans OEM NJ Engine and Power Adder Parts 0
arnie93lx FS:SPAL dual 11" electric fans/shroud Engine and Power Adder 1
M 96 GT w/ fluidyne rad & mishimoto dual fan set up! (pics how to fit fan) & how hot ?! 1996 - 2004 SN95 Mustang -General/Talk- 2
T Derale Dual Radiator Fans Fox 5.0 Mustang Tech 4
M 1996 GT w/ Fluidyne radiator + Mishimoto dual fans??? HELP SN95 4.6L Mustang Tech 2
juiced_94gt Want to install a Spal Dual Fan set-up...how to wire it? 1994 - 1995 Specific Tech 13
Ronald_McDonald dual or single electric fan Fox 5.0 Mustang Tech 2
W Dual fan wiring/alt Fox 5.0 Mustang Tech 9
68keyblr Dual electric fans? Classic Mustang Specific Tech 17
Y Derale dual electric fan 1994 - 1995 Specific Tech 3
jgfiveoh opinions on dual electric fans setup 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 10
T Ramchargers Dual Fan still exists? Fox 5.0 Mustang Tech 20
F Dual electric cooling fans Classic Mustang Specific Tech 8
9 Wiring In Thermostat Switch To RamChargers Dual Fan? Fox 5.0 Mustang Tech 6
C Installing Spal Dual Fan.... Fox 5.0 Mustang Tech 7
C Ramchargers 11" Dual Fan Fox 5.0 Mustang Tech 1
Killer50stang Front Dual Fan - Will It Do The Job? Fox 5.0 Mustang Tech 13
Grn92LX Just got my ramcharger dual fan, quick question Fox 5.0 Mustang Tech 8
NOSNotch Whos using Ramcharger dual fans? Fox 5.0 Mustang Tech 0
88GTtom Ram Chargers Dual Fan Question Fox 5.0 Mustang Tech 4
B Nissan stanza dual elec. fans? Fox 5.0 Mustang Tech 5
shinysideup turbo/supercoupe dual fans in my 5.0 Fox 5.0 Mustang Tech 2
kidtaurus Schematic for Dual Speed Taurus fan Classic Mustang Specific Tech 4
V Early fox body dual exhaust conversion questions Fox 5.0 Mustang Tech 4
J Single Exhaust to Dual Exhaust 1965 - 1973 Classic Mustangs -General/Talk- 0
beyondEOD 94-95 Mustang GT Auto Dual Microsquirt ECUs Digital Self-tuning Forum 14
T WTB/Trade Wtb... 289/302 factory dual quad manifold or complete set up. Engine and Power Adder 2
S Best dual plane intake for small block Windsor Other Auto Tech 19
6 Dual power master cylinder drum/drum conversion kits 1965 - 1973 Classic Mustangs -General/Talk- 5
R Fox Closed PCV System, Dual Valve Catch Can 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 2
GreenStangGT Picture request, dual tone cars? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 112
J Dual Exhaust 1965 - 1973 Classic Mustangs -General/Talk- 4
droopie85gt For Sale Spectre Dual Snorkel Air Cleaner Engine and Power Adder 0
B UPDATED. Newbie dual bowl master cyl 66 stang conversion question (drum/drum non-power) 1965 - 1973 Classic Mustangs -General/Talk- 0
GSnerraf Dual exhaust on my 03’ mustang V6 1996 - 2004 SN95 Mustang -General/Talk- 0
kiddiccarus Progress Thread 1995 3.8L Vert (2002 3.8L Dual Port Engine) 1996 - 2004 SN95 Mustang -General/Talk- 33
K Fox anyone use this dual port oil extension from scott drake? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 5
9 Dual piston calipers made no difference. Normal? 1996 - 2004 SN95 Mustang -General/Talk- 3
Similar threads