MSD

Are the pullies on the105 the same as the 145?

Holty

iTrader: (6)

I bet you $10 that if you upgraded your wiring you wouldn't need a new Alt.

Quik

iTrader: (7)

you can put th largest alternator on your ride and wont reak the benefits as much as you would with proper wiring. also you can push way to much current thru the stock wire which will cause it to get extremely hot and hot enough that it can cause a fire if something is aroudn it

the key is the size of wiring. look at a series of straws. you can have 200 psi on one side of a mixing straw. and you can have 50psi with the same straw....in the end same amount will only pass thru that straw. now if you go larger straw like a be slurpee straw then the 200psi will be more benefical

i in my truck run a 102 amp alternator, i have Efans, Electric water pump,decent stereo, AC on with headlights and fog lights on and i dont have no issues what so ever. my Alt is from an Fbody. stock trucks are 105...i also have and underdrive pully that is 25%.. and my voltage is never under 14volts!!!!!!!!!

this reason is my sizing of wires. i upgraded the redbox to alt wire, my grounds are 2/0 and my battery cable is 2/0....also remember my battery is all the way in the back!!!

also remember my EWP is on the minute the ignition is on so its a constant drain on the system

so save yourself money and upgrade the wiring

BlackGMC

iTrader: (31)

That is some good info, thanks for sharing. I will be upgrading my wiring after reading this post when I do my efan install next week.

Quik

iTrader: (7)

i also dont have spikes like some say they get when they kick in. last year i had only upgraded the Alt wire everything else was 100% stock location and wiring and had no issues either. i also didnt have the underdrive pulley or the EWP. and this year i have more and no issues.....minus the motor issue lol

MSD

quik.. Thanks for the great info. What size did you use for the alt. to red box wire

jknox

iTrader: (2)

Personally I wouldn't go to the red box. Alt to red box is a 8ga fusible link. Red box to batt is only 6ga. And then from the battery to the fuse block is only 8ga.

I look at it this way: the Big Audio Boys suggest to run heavy guage from the alt to the battery, but they also like running their gear straight from the battery terminal because they like to thump without the motor running. If you're not into maiming your ears then most of your electrical load is going to come when your motor is running. It makes sense in this case to go straight to the fuse block.

Here's what I did. With the full cover off of the fuse block you can see a spot for a big-azzed fuse on the left. One end has your battery cable and the other is open. I think the cover lists it as being a 145A "aux" power connection. Autozone sells a 175A that fits that location. Buy yourself a 2' 4ga battery cable with the smallest holes in the terminal ends you can find. In my case that was 3/8" from Tractor Supply. Stop by Lowes and get a bag of 6mm washers, 8mm washers, and some 8mm x 1.25mm nuts. The washers will let you get good clamping on the oversize holes in the terminals. Yank out the wire from the alt to the red box, and then take your new battery cable and go straight from the alt to the new fuse location. The new nut is for the originally unused stud for the fuse - mine didn't have one from the factory.

I'd also upgrade some grounds at this point. A second 2' battery cable can go from the alt bracket to the firewall ground point. And a 3' one can go from the alt bracket down to the frame - I used one of the bolts for one of the bumper side support brackets. And finally connect your ground for the fans to the alt bracket as well.

When I added in my fans I also swapped in a 145A alt, but I was noticing a small voltage drop on the voltmeter with everything going. After adding in the wire upgrades I don't see that anymore...

Quik

iTrader: (7)

i actually used a wire from a Trailblazer/etc its 6ga i think.....upgrade this wire and add larger grounds and youll be fine

Hemi Killer

iTrader: (6)

I'm not a "wire" person, does anybody have a write-up with pictures? Good info btw!

Holty

iTrader: (6)

Since this question comes up again and again here, I thought this might be a useful post. Performing a "Big 3" upgrade on your vehicle is one way to improve the electrical system performance and its ability to supply power to your audio system. This upgrade will help any vehicle using an after-market amplified stereo system, and most certainly should be performed on any vehicle after a high-output alternator is installed.
Please be sure you read and understand this entire instruction before you begin.

Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis. Some people replace the factory wiring; others add additional cables to the factory wiring. This instruction is to add cables to existing OEM wiring.

Parts and Tools:

As a minimum, you will need to purchase the following:

• Sufficient length of high-strand count high capacity power cable.
- The length required differs for every vehicle. You can measure the length of the existing cables and buy the same length, or contact your dealer or a mechanic and ask, or sometimes you can look it up in a manufacturer's wiring book, or guess. If you guess, make sure you over-estimate and buy too much.
- High strand count cable is more flexible and more reliable than low-strand count cable. Never use solid-core wire in a moving vehicle as it will eventually break.
- The gauge of wire you need depends on the total current draw of your audio system, and/or the current generating capacity of your alternator. Never use smaller cable that you used to power your amps; never use smaller cable than what already exists in your vehicle; never use smaller cable than the generating capacity of your alternator; never use smaller than 4 AWG (it's just not worth the time to use anything smaller); if in doubt, always use higher gauge cable than you think you need. If you look at the Power and Ground charts and your amplifier current draw corresponds to 2 AWG cable, use no smaller than 2 AWG cable, and use 1/0 if you can.

• 6 ring terminals or lugs of the appropriate size for the cable chosen. Two of these need to be large enough to fit over your battery posts, or appropriately sized to bolt onto your existing battery terminals.
• 1/2" or 5/8" shrink tubing (or some other form of permanent electrical insulation. Tape is NOT recommended.)
• Cable ties (plastic zip ties.)

• Wire cutters large enough to handle the cable you choose.
• Crimpers large enough to handle the connectors you choose.
• Soldering iron or gun.
• Solder.
• Scotch brite and/or a small wire brush.
• Heat gun.
• Safety razor blade (or other tool for stripping cable).
• Heat gun (if using shrink tubing).
• Wrenches for removing bolts in your vehicle.

Procedure:

1. Make sure your engine is completely cool before beginning. Identify the three cables being replaced. Make sure you can reach both ends of all cables. NOTE: the engine block to chassis cable may be between the engine and the transmission, or connected to the transmission and the fire wall, and is often an un-insulated flat braid cable.

2. Determine the lengths of cable needed to reach between the three locations being upgraded. Be sure you measure with a flexible tape (a tape measure used for sewing works great) and record the total length along the path you intend to install the cable. You do not want your cables to be pulled tight between any two locations as things move and vibrate as you drive. Be sure to include at least 1 inch extra for slack. NOTE: there is no reason to copy the existing wiring layout in your vehicle unless you want to. Also, be sure that the path you choose does not follow or lay across anything that gets hot, like exhaust parts, or anything that must move, like throttle linkage.

3. Cut your new cable to the three proper lengths. NOTE: some people like to use red cable for positive and black cable for negative. Doing this is completely up to you and is nice, but not necessary. You can use cable with any color insulation you like.

4. Strip each end of all cables to the proper length for the terminal lugs being used. NOTE: after full insertion into the lug, a small "band" of bare wire is usually seen between the back of the lug and the beginning of the cable insulation.

5. Begin at any one end and insert the stripped cable into the lug. Make sure it is fully inserted. Crimp the connector to hold the wire in place. NOTE: crimping large cable can be difficult. The intention here is not to make the crimp the sole means of holding the wire, but only to make sure the lug does not slip around during the soldering phase. I do NOT recommend using hammers or pliers or vices to crimp the connector as over-crimping can break the strands of the cable, reducing the current carrying capacity. Do not over-crimp.

6. You may need to use a vise or some other set of "helping hands" to hold the cable while you solder it. Heat your soldering iron and place it on the connector (on the lug side) barrel. Hold a piece of solder against the tip of the iron and melt the solder into the strands of the cable. Use sufficient solder to fill the connector and completely cover all strands of the cable. NOTE: the lug will get hot and will burn you if you try to hold it. Also, if the insulation on the cable starts to melt, you are over-heating the cable and not paying attention to melting the solder into the cable. You do not need to try and melt the cable!

7. Repeat the above steps on each end of all three cables.

8. After the cables have completely cooled, cut a piece of shrink tubing long enough to cover the soldered barrel end of the lugs and reach about 1/2" onto the insulation of each cable end. Slide this over each lug and use a heat gun to recover the tubing in place.

9. Disconnect your battery, starting with the negative cable first then the positive cable. Discharge any caps you may have in the system.