Another Alternator ?
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Another Alternator ?
I took my 73 F100 off the road for a while so I can tinker around with it. It has the factory 38 amp alternator on it and as far as I know the original regulator. The alternator will charge but when I first crank the truck I have to hit the gas to make the ALT light go out and make it charge. Would this be a regulator problem or a weak alternator?
I've been looking at new alternators for it and I found some at Advance Auto Parts. I found one part number 7078. This alternator is a 65 amp though and the smallest Advnace carries for the truck. Will this be a direct swap or will I have to change things? I didn't know if the stock regulator would work with it. Thanks.
I've been looking at new alternators for it and I found some at Advance Auto Parts. I found one part number 7078. This alternator is a 65 amp though and the smallest Advnace carries for the truck. Will this be a direct swap or will I have to change things? I didn't know if the stock regulator would work with it. Thanks.
Senior User
Joined: Mar 2009
Posts: 211
Likes: 0
Should be a direct swap, just compare the two and make sure they mount up the same. When you go to autozone, you can take your old alernator in and they can do a load test on it to see if it is charging properly, they do this for free. Then you can go from there as to what you problem is, how old is your battery also?
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Unfortunately, it's difficult to separate alternator and regulator symptoms. The problem could be that the alternator output is too low, and it takes the extra RPMs to satisfy the regulator. Or, the regulator threshold has drifted, and it takes more current than it should to shut off the light. Fortunately though, since the problem is fairly deterministic, you can take both the regulator and alternator to the store and have them tested.
The stock regulator will work with the higher amperage alternator. The amperage rating simply specifies how much current the alternator is capable of putting out - which is based on the number of windings in the alternator, among other things. The alternator doesn't continuously put out 38 or 65 amps - it only puts out what is required to maintain 12-14 volts across all RPMs. All the regulator does is tell the alternator how much current to output based on the load on the electrical system. If you've got a fairly stock truck (no giant fog lights, winch, high-power amp, etc) then the replacement alternator is going to do just fine.
The stock regulator will work with the higher amperage alternator. The amperage rating simply specifies how much current the alternator is capable of putting out - which is based on the number of windings in the alternator, among other things. The alternator doesn't continuously put out 38 or 65 amps - it only puts out what is required to maintain 12-14 volts across all RPMs. All the regulator does is tell the alternator how much current to output based on the load on the electrical system. If you've got a fairly stock truck (no giant fog lights, winch, high-power amp, etc) then the replacement alternator is going to do just fine.
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Thanks everybody. This truck doesn't have anything extra but a cd player. It is bare bones, lights, wipers, and heater.
I may get a new alternator and regulator from Autozone since it won't be to expensive. They have a 61 amp alt. I hear that some of the electrical stuff from Autozone is better than Advance Auto Parts.
Im ready for good weather so I can rip out my floor mat and get my floors prepared for new carpet.
I may get a new alternator and regulator from Autozone since it won't be to expensive. They have a 61 amp alt. I hear that some of the electrical stuff from Autozone is better than Advance Auto Parts.
Im ready for good weather so I can rip out my floor mat and get my floors prepared for new carpet.
Posting Guru
Joined: May 2006
Posts: 1,327
Likes: 1
From: Kingsport, TN
ANOTHER option is to have the alternator rebuilt. I did this years ago and had the guy boost it to 90 amps for about $30. A good shop can do it in about 1/2 an hour - if you schedule it. Most will also replace the brushes too.
Elder User
Joined: Jul 2003
Posts: 668
Likes: 2
Now that is AWSOME information. What was the total cost of the rebuild? I have a new spare in the shed I'd like to upgrade, or remove the working one on the truck and upgrade it.
Post Fiend
Joined: Oct 2007
Posts: 10,501
Likes: 5
From: Faibanks Ak.
Trending Topics
Elder User
Joined: Jul 2003
Posts: 668
Likes: 2
[QUOTE=starmilt;8412097]Lot of guys are going with a 3g off a taurus for 130 amp.
What years of Taurus and engine, etc? Are they a direct bolt up? Does it change the belt size width, lenth? Inquiring minds want to know details Man.......
On another note, one can make a SBC alt work with bracket\belt\wiring mod's...get my point.
I'd install one in a heartbeat, just...because.
What years of Taurus and engine, etc? Are they a direct bolt up? Does it change the belt size width, lenth? Inquiring minds want to know details Man.......
On another note, one can make a SBC alt work with bracket\belt\wiring mod's...get my point.
I'd install one in a heartbeat, just...because.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Zombie Survivalist
Joined: Feb 2009
Posts: 14,809
Likes: 3
From: Rock Springs, WY, USA
well, as far as I know, there is no way to test a regulator. tried to have that done, no go. but at $15 a pop, they arent expensive at all. and for fitment of the replacement alternator, just be sure they are about the same kinda build and would attach the same way.
Post Fiend
Joined: Oct 2007
Posts: 10,501
Likes: 5
From: Faibanks Ak.
[quote=Riderman;8412105]
That article is a 93 raurus I (think they were the same till 97) it tell you how to change your pulleys and modify your adjustment arm.
Several of the diesel guys have used them thsy are supposed to charge a lot better at an idle.
Lot of guys are going with a 3g off a taurus for 130 amp.
What years of Taurus and engine, etc? Are they a direct bolt up? Does it change the belt size width, lenth? Inquiring minds want to know details Man.......
On another note, one can make a SBC alt work with bracket\belt\wiring mod's...get my point.
I'd install one in a heartbeat, just...because.
What years of Taurus and engine, etc? Are they a direct bolt up? Does it change the belt size width, lenth? Inquiring minds want to know details Man.......
On another note, one can make a SBC alt work with bracket\belt\wiring mod's...get my point.
I'd install one in a heartbeat, just...because.
Several of the diesel guys have used them thsy are supposed to charge a lot better at an idle.
Thread Starter
|
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Thats cool, I may do that to my Bronco. I think for my F100 that is a little overkill since it has no accessories, lol.
Thread
Thread Starter
Forum
Replies
Last Post
LipschitzWrath
1973 - 1979 F-100 & Larger F-Series Trucks
22
Aug 14, 2017 05:22 AM
SpawnX
1983 - 2012 Ranger & B-Series
19
Apr 25, 2014 07:53 AM
toymachine13
401, 477, & 534 SD Engines
5
Dec 21, 2011 06:37 PM
rdnhood
1961 - 1966 F-100 & Larger F-Series Trucks
6
Jun 6, 2010 08:50 PM
