alternator

[LCAM-01XA]

Pulleys don't usually slip on the shaft, they get impacted on and they are a mother to remove without an impact too, have yet to see one that got loose on its own. Belt slipping on the pulley you'd have heard by now, bug time loud screamer!

Fuse links is probably not bad, if you saw voltage climbing over 13V that means at least for a short while the charging system was working decent...

Honestly man, in your situation I'd just go 3G and never look back, it's way simpler to work on it and it's also more powerful too.

 

[rhkcommander]

this should be a 3G, I just replaced the old one and thats what the symptoms were with the new 3G 130 amp alternator.

Just found this thread too : http://www.oilburners.net/forums/showthread.php?t=14573

also I did use the impact wrench to pop the old pulley off the old alt and swap it to the new alt . Going to try directly attaching the output wires (two medium gauge wires tied together) without the fusable link - the two output wires (that act like one) and the yellow wire all come together before the link, the gauge after the link is thin like 14ga max im guessing..

 

[LCAM-01XA]

Just bypass that fusible link BS and run a nice hefty charge cable between the alt and the battery directly. A fuse is your choice, I have one just in case. Then cut down the yellow battery sensing wire and loop it to the alternator's output stud directly, that will ensue it gets accurate reading and rule out potential corrosion or physical damage further down its length towards the factory fusible link.

 

[david_lee]

if the yellow wire is for the battery sensing, then it needs to be hooked up where most of the power is being tapped from and not at the alternator. voltage drop will not be as noticable at the alternator as it is at the(in my case) starter solenoid.

 

[LCAM-01XA]

David, this is true but it also depends on the size of the cable that's used between the different points. For instance I have 1/0 main charge cable dumping straight into the passenger-side battery, and with something so massive the voltage readings on both ends are practically identical. You have a large drop cause you use the factory wiring which in each and every older Ford vehicles sucks so bad it ain't funny, even a factory alternator can benefit from having a big charge cable - basically your factory charge cable is your electrical system's bottleneck right now, and just eliminating such weak links is a good way of increasing overall performance.

And since I mentioned the 1/0 cable - I also have a 4-gauge cable feeding the starter relay on the fender (factory is like 6-gauge), and I also have another 4-gauge cable powering up the glowplugs relay directly off the battery - this way I have significantly less current flowing through the factory wiring, and an overall more reliable setup. My alternator charge cable is hooked up to the battery, all my lighting (well over 1kW in power) draws from the batteries as well, but my voltage sensing wire is hooked up to the alternator stud - everything on including HVAC blower on high gets me 13.5V at high idle and between 13.8 and 14.2V while cruising at 1500-2000 rpms, I'd say my system is working rather good

 

[david_lee]

i see your point there. i havent really considered the current wiring because i have been busy with so many other things on my truck, but i will be adding the wiring to my to-do list now

 

[LCAM-01XA]

Understood, gotta prioritize

 

[rhkcommander]

gonna try that out today, should I run a fuse to the yellow wire? I have read mixed ideas about it. Same question for the massive power cable

thanks again

 

[rhkcommander]

redid the wiring and got a 4gauge wire on the power output, ran the yellow wire directly to the primary battery. Cleaned all the corrosion off the hots on relay and post/wires. Should be good 2 go. I made double sure it was the 130 amp one by checking for the two holes on the front. It is.

Batt's were dead - 12.5V but she nearly started. had partial combustion. Just not enough oompf out of the starter/batts. 1 bad glow plug too, only could reach the first 6 at the moment. What gauge wire should I use if I make my own GP harness? Going t o get a high-torque starter soon too

Feels better at turning/wanting to start. Now that the old alternator with seizing bearing is out. Will try again after the batts charge a bit more. Wish me luck!

 

[rhkcommander]

Victory is mine!

New 3G 130 amp alt worked great, voltage was above 14.5v just like its suppose to be!

I was wondering what sitting voltage I should have for a good battery in the dual battery setups like ours?

I'll take some pics when it stops raining

 

[pybyr]

Also what was the stock amperage of the oem alt? i am finding 60A to be a common replacement for stock alt at rock auto.

I'm also interested in knowing what the stock/ OEM alternator is/was rated at in my 1989 7.3 N/A-- my alternator is working OK, and the whole truck has very low miles, so most of me leans towards "if it's not broken, don't fix it" on this one- but if I likely have a smaller output alternator (60A seems as if it'd be tiny on a diesel truck with 2 batteries) then I wouldn't mind keeping an eye out for a good condition/ low-priced 3G for an eventual swap.

 

[rhkcommander]

been testing the new alt more, seems to work greatly. junk yard special too.

only problem i had was the belt is stretched so it wont be tight unless i rev her. looks scary as **** but ill replace it tomorrow prolly.

online the usual replacement i found was 60-80 amp, i could be wrong. but when the truck starts my batt gauge goes from bottom of the white to full.

 

[LCAM-01XA]

gonna try that out today, should I run a fuse to the yellow wire? I have read mixed ideas about it. Same question for the massive power cable

I got a 175-amp fuse on the big cable, and nothing on the yellow wire - well in my case yellow wire really can't get damaged, but even the way you did yours should be just fine without a fuse for it. For the big cable I'd suggest a fuse or better yet a circuit breaker that you can shut off and reset as needed.

What gauge wire should I use if I make my own GP harness?

The factory setup is two 10-gauge wires running off the starter relay on the fender. I kept this, but I pulled the wires off the big connector near the HVAC dryer and spliced both ends directly for a nice solid and corrosion-free connection. Then I added the 4-gauge cable from the battery directly to the glowplugs relay, so now current has an extra path to the GPR. Works great for me, but if I were to completely remove the factory wiring I'd use a 1/0 cable for the GPR power.

I was wondering what sitting voltage I should have for a good battery in the dual battery setups like ours?

Same as you'd have in a single-battery setup really - mine is at 13.something usually

I'm also interested in knowing what the stock/ OEM alternator is/was rated at in my 1989 7.3 N/A-- my alternator is working OK, and the whole truck has very low miles, so most of me leans towards "if it's not broken, don't fix it" on this one- but if I likely have a smaller output alternator (60A seems as if it'd be tiny on a diesel truck with 2 batteries) then I wouldn't mind keeping an eye out for a good condition/ low-priced 3G for an eventual swap.

IIRC it's either 60-amp or 75-amp. These trucks really don't need much more than that tho, especially those with hand-shaker transmissions (no PCM means 20 amps less draw as the truck is running)

 

[jim x 3]

Works great for me, but if I were to completely remove the factory wiring I'd use a 1/0 cable for the GPR power.

IMHO, this is ridiculous overkill. Assuming a 100A GP draw (because its easy to calculate - if you assume 200A you can just double my voltage drop figures) the voltage drop thru a 1/0 copper wire (about 6' long from battery to GPC) would be 0.06 volts. The voltage drop thru an AWG 6 wire would be more, but only 0.2 volts. There is a much bigger voltage drop thru the GPC's shunt. So why waste the copper?

Regards,

 

[SLC97SR5]

Sorry to resurrect this but what year Trucks had the 130amp alternators?

RockAuto lists mine as a 130amp 3G.

My Truck is a '94 Factory Turbo 7.3 4x4 e40d