electric fan help
- Thread starter noslow86
- Start date
Black 93 Fox
Active Member
Your stock one should be fine as long as you dont have a big stereo system or anything like that. I have the stock alt with underdrives and electric fan and have no problem.
slo65
New Member
Black 93 Fox said:
same thing here, no problem on the street, but when i get to the track it usually drains the battery by the end of the night, always push start it
, cant blame it though, i'm constantly starting/turning off the engine, running the electric fan, poor alternator 
Here's websites with pictures of the 3G installation...
See http://www.geocities.com/smithmonte/Auto/3G_130A_Alternator_Upgrade.htm - all the tech data you could ever want to know
OR
http://www.mustangcentral.net/tech/alternator.html - excellent pictures of installation
Use these sites for information on the right way to do the wiring. Some people will tell you that you can skip the wiring upgrade, but it will catch up with you sooner or later. A fire in the wiring harness is ugly and expensive.
Under no circumstances connect the two 10 gauge black/white wires to the 3G alternator. If the fuse blows in the 4 gauge wire, the two 10 gauge wires will be overloaded to the point of catching fire and burning up the wiring harness.
Electric fan = 3G alternator if you want long life & reliability from your car.
The electric fan saves some HP. The stock fan's parasitic drag runs from 7-12 HP depending on who you talk to. The electric fan uses about 1/2 HP of power from the electrical system.
Figure this:
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank!
See WWW.partsexpress.com for the fuse & fuse holder.
Fuse @ $3.90 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=071-952
Fuseholder @ $5.80 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-630
4 gauge black wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-196
4 gauge red wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-194
4 gauge ring crimp terminals (package of 5) $3.25. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=095-584
Don’t forget the alternator power ground!!!
The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.
See http://www.geocities.com/smithmonte/Auto/3G_130A_Alternator_Upgrade.htm - all the tech data you could ever want to know
OR
http://www.mustangcentral.net/tech/alternator.html - excellent pictures of installation
Use these sites for information on the right way to do the wiring. Some people will tell you that you can skip the wiring upgrade, but it will catch up with you sooner or later. A fire in the wiring harness is ugly and expensive.
Under no circumstances connect the two 10 gauge black/white wires to the 3G alternator. If the fuse blows in the 4 gauge wire, the two 10 gauge wires will be overloaded to the point of catching fire and burning up the wiring harness.
Electric fan = 3G alternator if you want long life & reliability from your car.
The electric fan saves some HP. The stock fan's parasitic drag runs from 7-12 HP depending on who you talk to. The electric fan uses about 1/2 HP of power from the electrical system.
Figure this:
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank!
See WWW.partsexpress.com for the fuse & fuse holder.
Fuse @ $3.90 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=071-952
Fuseholder @ $5.80 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-630
4 gauge black wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-196
4 gauge red wire @ $1.25 a foot (use string to lay out routing & determine length) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-194
4 gauge ring crimp terminals (package of 5) $3.25. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=095-584
Don’t forget the alternator power ground!!!
The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.
351LX
Founding Member
One thing people tend to forget is that there are millions of 4 cyl Mustangs around with electric fans from the factory.Check the amp requirement of the fan you want to use and if it isn't much more than the factory 4 cyl fans you should be fine.
Figure this:
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank!
ok figure this you stock mustang alt is at 65 amps but.......... ALL alternators are rated at 85% max output for reliability resons! 65\85%=76.470588 amps! And if all your stuff is pulling that many amps you have a problem! A cpu pulls maby 2-5 amps MAX!your spark systems dosent need amps due to the laws of electromotive force and step up voltage transformers!bigger alts are a waste of money if you dont have a "big" bumpen system your car will do just fine with a elect fan it will pull about 15 amps!
Note fuses are there to protect wiring not the componits!
Oh yea ASE master Certificate # lu0mp6x04mcgro
And FAA Airframe and powerplant #2799069
Oh and faa pilot single and multiengine aircraft#2799069
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
That's grand total of 74 amps from a 65 amp alternator. Talk about overdrawn at the bank!
ok figure this you stock mustang alt is at 65 amps but.......... ALL alternators are rated at 85% max output for reliability resons! 65\85%=76.470588 amps! And if all your stuff is pulling that many amps you have a problem! A cpu pulls maby 2-5 amps MAX!your spark systems dosent need amps due to the laws of electromotive force and step up voltage transformers!bigger alts are a waste of money if you dont have a "big" bumpen system your car will do just fine with a elect fan it will pull about 15 amps!
Note fuses are there to protect wiring not the componits!
Oh yea ASE master Certificate # lu0mp6x04mcgro
And FAA Airframe and powerplant #2799069
Oh and faa pilot single and multiengine aircraft#2799069
jrichker said:
I realize that you have far more knowledge and experience than most other people who post here, but I've read 5 or so magazine articles about doing the 3g upgrade, and they all say to make sure to reconnect those wires, supposedly because there are circuits which depend on power from those wires, which apparently aren't satisfied by the 4 gauge wire you run. I'd like to see a full wiring diagram to prove that wrong once and for all, because I personally would like to know which way is correct.
Wow, this thread went to poo. 
JRrichker's theory is correct. One keeps the stock charge wire(s) attached on the solenoid side (not at the alternator - tuck those wires/that connector away). One could redo all the stock wiring so that the voltage-sensing wire is retained but the stock charge wires are removed completely (the main point of keeping the stock charge wires attached at the solenoid is not for the stock charge wires at all), but it is easiest to tell folks to just keep the solenoid-side wires intact and attached.
Mr. Richker's little toe knows more than I do, but as far as I can tell, he is completely correct on how to wire the alt.
I have spoken with Mr Smith as well. He was more than willing to share his opinions.
I wont address what I thought of a post up a couple from this one. I guess we all have issues since our 2G's leave a LOT to be desired and lave a lot of us wanting more. :
JRrichker's theory is correct. One keeps the stock charge wire(s) attached on the solenoid side (not at the alternator - tuck those wires/that connector away). One could redo all the stock wiring so that the voltage-sensing wire is retained but the stock charge wires are removed completely (the main point of keeping the stock charge wires attached at the solenoid is not for the stock charge wires at all), but it is easiest to tell folks to just keep the solenoid-side wires intact and attached.
Mr. Richker's little toe knows more than I do, but as far as I can tell, he is completely correct on how to wire the alt.
I have spoken with Mr Smith as well. He was more than willing to share his opinions.
I wont address what I thought of a post up a couple from this one. I guess we all have issues since our 2G's leave a LOT to be desired and lave a lot of us wanting more. :
MeanMussy
Founding Member
I thought this was going to turn into a sword fight for a second. anyways..
Yes, it is a good idea to add a 3g w/ an electric fan. Anyone that has ever watched their headlights dim when turning on the blower knows, that the 2g output is marginal for stock accessories. Add the draw of an electric fan (which can draw some serious amps.. ), and you're pushing what it was designed to do. But.. you will be able to get an electric fan to turn over w/ your stock alt. If you don't do a lot of stop and go driving, and don't hit the track a lot, you probably won't see too many charging problems. But, if you're car idles for much time, you'll be glad you have the extra capacity of the 3G.
I could toss out some credentials if you really need them to believe me, but I don't think that's needed.
Yes, it is a good idea to add a 3g w/ an electric fan. Anyone that has ever watched their headlights dim when turning on the blower knows, that the 2g output is marginal for stock accessories. Add the draw of an electric fan (which can draw some serious amps.. ), and you're pushing what it was designed to do. But.. you will be able to get an electric fan to turn over w/ your stock alt. If you don't do a lot of stop and go driving, and don't hit the track a lot, you probably won't see too many charging problems. But, if you're car idles for much time, you'll be glad you have the extra capacity of the 3G.
I could toss out some credentials if you really need them to believe me, but I don't think that's needed.
mike0227 said:
Some of the current figures may be a little off, but not much. The fact that the computer power & ground is fed by two 14 gauge wires gives some clues about the current draw. ( see http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif ). Also on the computer power feed circuit are the fuel injectors, and all the actuators for the EFI. They draw smaller amounts of current, but it adds up. Ford is cheap and large gauge wire is expensive. If they could have gotten by on a single 18 gauge wire (using the 2-5 amps you quoted) they would have done it.
The most common electric fan I have seen is the Lincoln MK VIII, which seems to pull about 20-30 amps running current and 60 amp or greater startup spikes. Some other fans may pull more or less. The size of the wire is often a clue. Units that use 15-20 amps can get by on 12 gauge wire, units that pull 20-30 amps will use 10 gauge wire.
The alternator saver is the DC Control fan controller (http://www.dccontrol.com/) because it feeds the fan only the minumum amount of current to maintain the preselsected temp. They guys running the DC Control unit can get by with the stock alternator. The drawback is that the small 30 amp DC Control kit is $110, almost the cost of a 3G conversion. The 60 amp kit is $150, which is probably the one I would chose for a MK VIII fan.
If you measure the resistance of a typical ignition coil, you will probably get .4-1.0 ohms. Using .5 ohm as an example (I=E/R), thats 24 amps of current. The inductive reactance ( Xl=2pi times fL) of the circuit causes coil's resistance to increase to about 1 ohm, reducing the current to about 12 amps, but not down to a low figure like 2-3 amps at low speeds.mike0227 said:
As far as credentials go,
FAA A & P 2032759, issued 11 May 1970 (inactive since 1979)
Associate of Science in Electronics, Jan 1979
26 years of fixing computers, the first 10 years doing chip level repair.
If you want to have a spitting contest, let's take it offline. Email me at [email protected]
Not to step on anyone's toes, but IMO either way is fine with the old charging wire(s). It's probably best to do what jrichker suggested, and not connect them at all. However, if you did connect them, you would still be pretty safe because there are fused links on the old leads.
The stock setup consists of two ~6" lengths of black/orange 10ga wire, which are spliced with a fused link to a single 8ga black/orange wire. This is the main power lead for the stock alternator. It's about 9' long, and runs from the alternator area, in front of the radiator, and then connects to a 12ga brown wire (which is only about 4" long and spliced to the yellow/white voltage regulator sense/switch lead) at another fused link. These two wires go to one singe 8ga green lead, which ends in a ring terminal with yet another fused link, and it connects to the starter solenoid.
Now, to answer sgarlic's question...
Those articles are partially right. The problem they are talking about arises when you just pull the whole factory power lead out. If you disconnect it at the solenoid too, you are cutting power to the voltage regulators sense/switch line, and this causes problems obviously. Even if you don't connect the old power lead(s) to the new alternator, the sense/switch lead has power because it's still connected at the solenoid. If you take out the factory power lead all together, you just need wire the sense/switch lead to another source. The downside to this is even if you have the power leads disconnected at the alternator, they are still live, so you need to be careful if you just tie them back. If you insist on doing it that way, it's best to cut the ends clean, and tape/heat shrink them up good.
All that being said, IMO, the best way to do it is to rewire the sense/switch lead to the main charging post on the 3G, and disconnect the power leads at both ends so you don't have live and old wiring hot for no reason. I personally opened up the made in Mexico *cringe* wiring bundles , and pulled the whole thing out and just rewired everything. I figure if you are going to upgrade the charging system, you might as well take the time to just rewire everything right, and you'll never have to worry about it again. The more I worked with the factory Ford wiring, the more I wanted to tear it all out.
I hope this clears things up...
Edit:
Here's a pic of the solenoid side of the factory charging lead...
The stock setup consists of two ~6" lengths of black/orange 10ga wire, which are spliced with a fused link to a single 8ga black/orange wire. This is the main power lead for the stock alternator. It's about 9' long, and runs from the alternator area, in front of the radiator, and then connects to a 12ga brown wire (which is only about 4" long and spliced to the yellow/white voltage regulator sense/switch lead) at another fused link. These two wires go to one singe 8ga green lead, which ends in a ring terminal with yet another fused link, and it connects to the starter solenoid.
Now, to answer sgarlic's question...
Those articles are partially right. The problem they are talking about arises when you just pull the whole factory power lead out. If you disconnect it at the solenoid too, you are cutting power to the voltage regulators sense/switch line, and this causes problems obviously. Even if you don't connect the old power lead(s) to the new alternator, the sense/switch lead has power because it's still connected at the solenoid. If you take out the factory power lead all together, you just need wire the sense/switch lead to another source. The downside to this is even if you have the power leads disconnected at the alternator, they are still live, so you need to be careful if you just tie them back. If you insist on doing it that way, it's best to cut the ends clean, and tape/heat shrink them up good.
All that being said, IMO, the best way to do it is to rewire the sense/switch lead to the main charging post on the 3G, and disconnect the power leads at both ends so you don't have live and old wiring hot for no reason. I personally opened up the made in Mexico *cringe* wiring bundles , and pulled the whole thing out and just rewired everything. I figure if you are going to upgrade the charging system, you might as well take the time to just rewire everything right, and you'll never have to worry about it again. The more I worked with the factory Ford wiring, the more I wanted to tear it all out.
I hope this clears things up...
Edit:
Here's a pic of the solenoid side of the factory charging lead...
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