Alternator Ground Cable Addition and Modification 2004 thru 2008 F 150

[@douglasking6714]

Did the alt have a spot fir negative.or dud you just take a bolt lose and mount it

[@StilesAutomotive]

Douglas, Yep, my Alternator has a Pad with a Threaded Hole on it that was not used, but is for this purpose. I had to provide the new Bolt. - Stiles

[@monkeyhammered5239]

I have a 6G alternator. Do you think I could use the same size bolt to ground my alternator exactly how you’ve grounded your alternator. It has a grounding “pad” on the back that’s threaded.

[@StilesAutomotive]

Hammered, Yep I think you should be able to. You have to verify that your Alternator does indeed have the Pad for the Grounding Lug on the back. I believe (don't know absolutely) that all of this style of Alternators have this Pad. - Stiles

[@Skyefuego]

Where did you connect the positive wire on the alternator. On mine, there are two places that have positive coming out of it.

[@StilesAutomotive]

Skye, Take a look at this video, I show you the Alternator Connections: Alternator and Drive Belt Replacement 04 thru 08 F-150 5.4 L kzbin.info/www/bejne/n5LMn5h3qq2MrLc Let me know if you have any other questions! - Stiles

[@mikerangel1545]

Could this help eliminate engine noise to the car audio system?

[@StilesAutomotive]

If you have rewired your car or truck, yes it could help. Make sure you audio cables are not routed by any of the "big 3" cables of any power cables to your amps and other high load devices. Good grounds are over looked and very important. - Stiles

[@JokersHangout]

The good grounding system from the truck will give you a great power source to your audio system because of more steady current and returned but as far as your head unit or amplifiers go the grounds need to be as close as possible to the units don't worry about the performance of the truck when it comes to grounding audio

[@roncar12]

I think you said you put a high output alternator on your truck, what amperage did you go up to? I've got 4 gauge cable from putting my son's amp in but not entirely positive 4 gauge is correct since I'm putting a 250 amp HO alternator on the vehicle.

[@StilesAutomotive]

Ron, I think this one is 120 amp, it is a new Motorcraft Alternator, I don't remember the PowerMaster that it replaced. Remember, Welding Cable has more load carrying capacity than Automotive Cable, you should read what the Cable Manufacturer say about Load Rating. And remember that the Welding Cable is at 120V or 240V generally. So if a 4 Gauge Cable is rated at 100 amps (most are) than that is a lot at 12 volts. - Stiles

[@Sheeeeeeeeeeeeiiitt]

I just installed a new positive terminal on my battery. I am trying to locate a diagram that list where grounds are located so I can service them. Mine is an 09. When people refer to “check your grounds” does that mean the various metal braided straps? Are there any inside of the cab or all just underneath? Thanks again for sharing an informative video. Also the comments are helpful too.

[@StilesAutomotive]

JP, Yes the uncoated braided straps in the Engine Compartment are grounds. And almost every major component has its own ground (or is ground thru its mounting bolts). For cheap Wiring Diagrams Clinton's Manuals are pretty good (the other information is often generic). If you like the Truck and will do other Wiring / Troubleshooting work buy a real Ford Wiring Diagram Manual from Helm Inc (link below). If you do a google search it is sometimes hard to determine if you have the correct information. - Stiles Helm is the publishing company for OEM Owner's, Shop, and Wiring Diagram Manuals www.helminc.com/helm/Result.asp?Style=helm&Mfg=FMC&Make=FRD&Model=F150&Year=2009&Category=&Keyword=&Module=&selected%5Fmedia=

[@Sheeeeeeeeeeeeiiitt]

@@StilesAutomotive Hey, thanks a lot for the great feedback and for replying so soon.

[@standhd]

I have a 2003 F150. I’m thinking about running a bigger charging cable to the back of the alternator. Were in the back and how big of wire?

[@StilesAutomotive]

Earl, I try to answer these type of questions within 24 hrs. Sorry for the delay. I think I used 4 Gauge Welding Cable to replace the Positive Cable on my Alternator and I used the same 4 Gauge Cable to add a Ground Cable. Most Alternator have a Positive Stud to connect to. 4 Gauge AWG (normal automotive wire) (allowing for a 2% or less voltage drop at 12V) will carry 200 amps for 4.7 feet. That is about the length of my new Alternator Cables. Note that Welding Cable with finer strands of wire in them will carry more amps. If you feel like this is not enough for your application, I run 2 Gauge Welding Cable for my Battery Cables, 2 Gauge AWG (at 2% drop) 300 amps for 4.9 feet. (Remember Welding Cable is much more. Get a chart for the Welding Cable you are buying. Use caution when doing this, Alternator Power Cables (from the Positive Post on the Alternator to the Positive Battery Terminal) have a Fusible Link in them. This is a Fuse that looks very similar to Automotive Wire. I recommend you use a Fuse in your new Cable and you make an extra effort to protect the cable from damage. Let me know how it goes! - Stiles

[@standhd]

@@StilesAutomotive Ok I did it, but the ground wire from the alternator bracket bolt could not reach the negative battery terminal. So I instead fastened it to a bracket near my firewall. It is painted black, however and then I had a whine inside of my truck that reminded me of my amp/subwoofer days. I listened to one of my door speakers, but I heard nothing, even with the radio off. My truck still has the factory sound system in it and I plan on upgrading it at a later date. The whine seemed to be coming from under the dash. It would get a little louder when I accelerated, then go away altogether. But at idle, and low acceleration, it was definitely noticeable. So I finally unhooked the wire, and the sound went away. I relocated that wire to a factory ground strap from the frame to the chassis under my truck. My question is, we’re was the whine coming from? It was definitely an alternator whine, but it wasn’t coming from my factory speakers. I plan on getting a longer ground cable and doing it the right way from the negative battery terminal to the alternator bracket bolt. Thanks for your reply!

[@bernardocisneros4402]

@@standhd It's called Electro Magnetic Interference (EMI). The new negative wire you installed from the alternator to the bracket near your firewall, was carrying current, this current causes a magnetic field outside of the wire. This magnetic field interacts with anything that's electrical and nearby. Since it was close to the dashboard, it interacted with wires in your dashboard.

[@standhd]

@@bernardocisneros4402 Thank you for your reply. Should I disconnect it?

[@bernardocisneros4402]

@@standhd If the noise doesn't bother you, leave it there. If it bothers you then, disconnect it from there and connect it to a spot that's not too close to the dashboard. It's always best to connect it to battery negative, but if you can't, connect it away from dashboard or firewall.

[@nizamkechek1150]

Means i have to use 2 cable? -1 cable from positive battery to alternator -1 more cable from negative battery to alternator Is that right?

[@StilesAutomotive]

Nizam, Yes, you got it. I used 2 cables, a new one to replace the old Positive Cable from the Alternator to the Battery, and a new Cable for the new Ground Cable (from the Battery Negative Terminal to the Alternator Body. This improvement makes it so the current doesn't have the use the existing Engine Grounds (which most people have never cleaned, and you should if your truck is over 10 years old). The idea is to get as must power from the Alternator as possible. You don't have to use 2 Cables like you stated, but I did and I recommend it. - Stiles

[@nizamkechek1150]

@@StilesAutomotive thank you sir.. Do you use any fuse for that?

[@StilesAutomotive]

@@nizamkechek1150 I did not, but the Original OEM Cable likely had a Fusible Link in it. The risk is, if the Alternator ever gets a dead short in it, it will get very hot! I've never had this issue, but it could occur, I think. - Stiles

[@nizamkechek1150]

@@StilesAutomotive oh i see.. Thank you very much sir..you help me a lot..

[@334_david]

So no big 3 ?

[@StilesAutomotive]

No, I always thought I'd do the Starter Cable when I changed to a Power Master (or other) Starter, but my OEM Starter has been doing fine with the dual Batteries. I do need to finish the video on the Dual Batteries install. My Snow Plow is the big power draw for me and it has its own Power and Ground Cables. I have a video that shows you how to make the cables, you just need to figure out the length of the starter cable. Some day maybe I'll do it. Thanks for the comment. - Stiles

[@grady.stu.8300]

Alternator are ground to the block. That's why No factory strap or wire

[@StilesAutomotive]

Grady, That's right, the Alternator is grounded thru its mounting bolts to the Engine. The Engine grounded one or more places. My addition of a Ground Cable is explained in the video, to add a direct ground path to the Battery. For maximum power conduction and reliability. Are you just make a statement or ? - Stiles

[@bellawright4265]

No need to do this. Alt is grounded to engine. Adding those cables is a waste of time and money...won't change a thing.

[@StilesAutomotive]

Bella, Yep, that is why I said in the video; "worst case the addition just adds weight to the Truck." However, as your Truck gets older, the ground(s) to the Engine become corroded and this cable may provide a better ground path, which will help your Starter and Electrical Components. What if you painted your Alternator Bracket and Alternator like I did in the video? You will likely not have a good ground thru the Mounting Bolts. Electricity flows thru the path of least resistance, this new Cable will provide that path for the Alternator. - Stiles

[@bernardocisneros4402]

@@StilesAutomotive If you live in the rust belt, you're battery and alternator will thank you. I live in Chicago, so we have our share of cold n snow n salt on the roads. I've seen a lot of issues on older vehicles caused by bad grounds due to rust, so if you live in the rust belt, consider this a long term investment.