Bigger Alternator - Diesel Forum

dieselglory · 01-28-2006, 07:58 PM

I need a higher outout alternator for my truck. When i use my plow the lights dim badly and guage goes down to about 10-11 volts. How big can i go and a direct replacement also. I dont wanna do any heavy modification to get it in... thanks

cdnsarguy · 01-28-2006, 08:03 PM

What amp do you have now ...should be stamped on the cover or tag.

four27cobra · 01-28-2006, 08:53 PM

You should be able to bolt on the ambulance package alternator if you want more power, it came with the ambulance rigged chassis. I believe kragen sells them, maybe autozone too.

Runboy · 01-28-2006, 09:12 PM

60amp is "standard", book showed 100amp optional. Probably ambulance package. I think the 100 is internally regulated rather than external. May want to make up a fresh heavier gauge lead from the alternator to the starter solenoid.
Mike

cdnsarguy · 01-28-2006, 11:39 PM

My 93 has a 130 amp internal regulated came standard...... [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Runboy · 01-29-2006, 02:17 AM

Is your 93 serpentine or v-belt? Maybe they up'd the output option with the serpentine's?
Mike

cdnsarguy · 01-29-2006, 09:18 AM

Mine is serpentine, but that is only a pulley difference and I'd think changing it over could be an option.

Dieselglory have you done the the headlight mod.....

http://www.ford-trucks.com/article/i...r_Brights.html

Mr_Roboto · 01-29-2006, 12:39 PM

An 87 would be the old style alternator, I believed they switched to the newer style (3G) sometime in the early 90's. The 3G's had a lot higher output than the older alternators... They are also a lot more expensive!

One of the problems with plowing is that the motor isn't running at very high RPM's, so the alternator isn't charging much anyways. And most of the custom "high output" alternators don't charge at all at low RPM...

The best bet is to find the highest output bolt-in alternator. Also make sure the batteries are good and have good connections. The batteries are the "buffer" for the electrical system, so that the alternator does not have to try to do all the work in a high load situation..

OkieGringo · 01-29-2006, 12:49 PM

Mr. Robo, would trying to change the pulley ratios make a difference? Adding a jackshaft setup to spin the alternator faster. Just a thought for you guys with a shop and tools and "too much time on your hands". Man I miss my shop. Would one of you guys PLEASE buy my house in Baja? I need a shop!!!! [img]/ubbthreads/images/graemlins/shrug.gif[/img]OkieGringo

dieselglory · 01-29-2006, 03:45 PM

ok to awnswer ?s 87 truck with 93 7.3. it has v belts. What is the headlight mod? And i dont know what alt is in there now cant find any markings on it, and the batts are brand new 1000 ccas and connections are clean and tight. maybe i should just go and buy the ambulance alt. would i have to modify the wiring do to it now being externally regulated? Thanks

Mr_Roboto · 01-29-2006, 08:20 PM

[ QUOTE ]
Mr. Robo, would trying to change the pulley ratios make a difference? Adding a jackshaft setup to spin the alternator faster. Just a thought for you guys with a shop and tools and "too much time on your hands". Man I miss my shop. Would one of you guys PLEASE buy my house in Baja? I need a shop!!!! [img]/ubbthreads/images/graemlins/shrug.gif[/img]OkieGringo

[/ QUOTE ]

It would take a smaller pulley to turn the alternator faster. If it were possible, I would certainly do it. However, alternator pulleys are usually already pretty small.

I have the same issue with my ambulance turned work van. 165 amp alternator, low charge at idle. It has a high idle switch to run the engine at 1200 rpm to get the full charge.

Birken Vogt · 01-29-2006, 08:29 PM

If you get an ambulance alternator you should not have a problem with the "low charge at idle" issue. That seems to be limited to custom aftermarket stuff built on a standard size case. The Leece-Neville and Niehoff stuff is a much larger case and made to put out the amps all the time. I am not certain if the single v-belt is up to the task, however.

Birken