3G: Fused Finally

glowstang93

glowstang93

20+ Year Stangneter :roc</strong><span class=
Feb 9, 2003
853
8
39
Illinois
#1
4 years ago I installed my 95 amp 3G alternator. Great improvement, have had no problems at all with it. Unlike the stock 75 amp alternator that craps out every 2 years and doesn't have enough amps to run anything besides the engine. Been reading posts and decided I should a fuse on that power wire and increase the gauge just in case the unthinkable happens.:rolleyes: Untill today, this 10 ga wire is what I had for a power wire from the alternator to the solenoid.
View attachment 453102

I now have 4 ga cable with a Bussman fuse holder w/100 amp fuse. Here is the link for the fuse holder. I got mine from the local Napa. http://www.bussauto.com/products/powerdist/

I used the Bussman fuse holder, A Napa 100 amp wafer fuse, a 19" and a 49" switch to starter battery cable 4 ga. All together about $30.00.

It was a little hard to find somewhere to mount the fuse holder, but ended up with the drivers side fender behind the strut mount. Had to use a spacer to mount the holder straight. I will be working on a black molded plastic piece to make it look better in the future.

View attachment 453104

View attachment 453106

View attachment 453108

View attachment 453111

Picture of the solenoid where the cable was attached coming from the fuse holder. It had two nuts on it, but due to the bigger cable, I had to take one off then use it as a partial double nut on the solenoid stud.
View attachment 453113

Picture of the back of 3G alternator. Had to change the end of the cable to fit this connection, only one that didn't fit without major modification.
View attachment 453115

Thank you to all the fellow stangers on here for their help on this topic.:flag:
 
#3
Thanks. I almost didn't take the pics because I was afraid that someone would see some dirt. I haven't cleaned on the engine in about a month and I hate to admit it, but I think it has been at least 2 weeks since I washed her. Got to get that done tomorrow maybe.
 
#4
Nice job. I just did my new 130amp 3g last week. I used a 125A mega fuse and holder mounted to the engine side of the driver's side strut tower. I ran 4ga wire from the alt to the fuse and from the fuse to the solenoid. Turned out very nice. I completely removed the 10ga wire and just ran the voltage sense wire including the fuse link alongside the new 4ga. and terminated it in the same place at the fuse. I also covered the 4ga wire with spiral loom wrap to keep anything from chafing through the insulation and turning my charging system into an arc welder. It works great!! The stock volt meter isn't very accurate so I used my Fluke meter to check voltage drops with all accessories and the stereo on. With everything on I'm dropping less than a volt at idle. I've got 14.4 with everything off at idle.

Did you do anything about the sloppy bolt hole on the top bracket? I've got a quick and easy fix for that! I posted it on TF when I got done but forgot to post it here.
 
#5
Do u mean the alternator bracket? No I just inserted the bolt from the back and tightened it up. Really didn't notice anything real sloppy. I did use a hardened washer between the bolt and the alternator. Post up the link for your fix, would be glad to take a look at it. Thanks View attachment 452899
 
#6
Most write-ups tell you to through bolt the upper mount with a 3/8" bolt. No big deal rally as it fits the alternator just fine. However, the original upper mount is significantly larger in diameter. It was enough to make me go hunt a spacer to bush the hole. Being lazy I rummaged through the stuff I had here at the house and found a 1/4" NPT pipe nipple that would actually start to thread into the upper mount hole. I know the hole isn't threaded, but we're talking galv. steel vs. aluminum. Guess who won :) Anyway, I threaded it into the hole so that it was flush at the backside. I then cut the remaining length of pipe off with my cutoff wheel. Now to deal with the inner diameter. A 3/8" bolt ain't gonna fit in a 1/4" hole, I don't care how big your hammer is. :) So just grab a 3/8 or 17/32 drill bit and open the hole up to fit the bolt.

I'd take pics of my engine compartment, but after seeing yours, I'm embarrassed. I still can if a visual will help, but no laugin' dammit!! :D

EDIT: I was looking closely at your pics and it looks like your upper bolt hole is threaded on your alternator. Mine wasn't. I don't know if there's a difference in original application or what. It may not even be an issue in your case.
 
#7
I won't laugh, I can't stand it when people poke and laugh at other people's rides. My alternator was a stock alternator for say a 92 or 93 Ford Econoline or Van. So the case may be somewhat different.
 
#10
new info

I talked with a guy from PAPerformance and he suggested that I use a 150 amp fuse instead of the 100. He said a good rule of thumb is to figure 95 amp alternator, rounded is 100 x .20=20 100 +20=120 120 x .2= 24 120 +24=144. He also said that if the battery was low, like say you left your lights on or ran stereo for a while and went to start the car. There would be an increased load on the alternator and would probably blow the 100 amp fuse. So, I went to Napa and ordered a 150 amp fuse. I will keep the 100 amp fuse as a backup in a pinch though. I had a mechanic at work put a load on it and check for the output. It got 14.4 volts with 178 amps. This is because a 95 amp alternator puts out a minumum of 95 amps. PA also clued me in on why the voltage drops so much when the compressor is on. Its because it is pulling juice and also mechanical.
 
#13
Maybe I need clarification. I always understood alternator ratings to be the maximum current the alternator could produce under max load.

Anyway, the table basically tells you how long it will take for the fuse to open at a given percentage of the current rating on the fuse. To do the math, "In" is the current rating for the fuse. Looking at the table, it says that it will take a minimum of 4 hrs for a 100 amp fuse to blow under 100amp load. and 2-30 minutes to blow under 135amp (135% of 100) load.
 
#14
Here's a nifty little fuse holder I grabbed at Pick-n-Pull. These come stock on all 90's Ford Contours. Got the holder with 175a fuse for $3. Or, if you're so inclined, it'll fit in your pocket too!:lol:

175Afuseandholder.webp
 

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#16
That is a cool find. I love Jy's.

Rustbucket I think I am seeing now what you are saying.

If I use the 100 amp fuse it would take a min of 4 hrs at 100 amps for this fuse to blow. If the alternator would put out 135 amps, it would blow between 2 min and 30 minutes. I wish I knew what the alternator was actually putting out under normal conditions. I wouldn't think that it would be putting out 135 amps though because when they load tested it, the max was 178. So with this line of thinking, the 100 amp would be more than adequate, maybe even a little high, but probably a good decision to stay with.

I have made a decision. I will use the 100 amp fuse, but I am still going to have a 150 amp one on hand just in case. If all goes well I can always sell the 150 on ebay.:D

Rustbucket, do u agree that the 100 amp is a good choice since it is close to the 95 amp rating of the alternator?

I do value others opinions, especially on technical info. Thanks
 
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