Howdy...What does installing a 3g alternator do for the truck? I can understand if someone puts on a high output 130 amp or something like that to charge up trailer batteries, but how does a regular run of the mill 3g help?

Thanks alot...

 

Well a lot of people upgrade because the connector for a 2G alt. eventually turns into some type of fire hazard.

I have a 1G alt, it's good enough for me and they are cheap.

 

Like Sw1tchfoot said, I think the main reason is the fire hazard. I've seen what it can do to an engine bay (not on my truck), and it's not pretty. I still have the 2G in the '86 and have had no problems. Used lots of dielectric grease on the connections. The 3G is basically only two wires to make it work too, one to switched power and the other to the battery (or starter relay), so it makes for a really clean install. That's what the '81 is getting.

 

Ok Guys...Thanks for the info...I've had my truck for many years. Never had a problem with the altenator, but maybe I better check all the connections and wiring just for cautions sake...I kept seeing where everyone seemed to be swapping in a 3g and was just curious...

Thanks again

 

I am running a GM alternator on my Ranger, for the same reason, the 2G went out and they are too expensive and have too many problems to mess with. The GM is a simple 2 wire deal also.

 

I did the 3g upgrade on one of my trucks, it's a fairly easy swap, I noticed right away that when you have your lights on at night they seem a little brighter, and when you put on the turn signal at a stop the dash lights don't dim too. When i get a chance I want to get one for my other truck also.

 

its all the fire hazard stuff mentioned above, plus the higher output for those of us who have added loads on the system. things like fans, high output sound systems, extra lights, etc, all put more load on the charging system and increase the fire hazard of the factory system.
and the 3g is available for dirt cheap at every junkyard in town with a pigtail of a wire harness included.

 

its all the fire hazard stuff mentioned above, plus the higher output for those of us who have added loads on the system. things like fans, high output sound systems, extra lights, etc, all put more load on the charging system and increase the fire hazard of the factory system.
and the 3g is available for dirt cheap at every junkyard in town with a pigtail of a wire harness included.

 

I wonder if I were to upgrade if my truck and 5th wheel lights would burn a little brighter because I have always thought they were a little dimmer as compared to newer rigs I see at night?

You guys say I can find a set-up at a junk yard. How can I identify what is a 3g altenator and what vehicle(s) would have one? You guys and this 3g upgrade makes me want one. Also...do they come in higher amp outputs? Sure would be another way to help keep my 440 amp deep cycle battery bank charged up huh...

Thanks Guys for the info...

 

The 130amp is the highest amp version I have heard of so far. Do a google search on "3G swap" and you will get lots of info and lists of what vehicles have what you want. Certain 3G's are easier to swap than others. Some require a little bracket modification to fit. The GM I installed was a larger diameter unit, and required a little bracket modification to fit the Ranger.

 

If you use your trailer a lot, I believe I would be modifying the running light circuit with a relay. I see all the time relay mods for the headlights, but haven't seen much talk about the running light circuit, and it's the one that melts the wire and burns up the tan/white wire at the headlight switch, a very common problem.

It would require a little bit work to do though, since the headlight switch would have to be pulled and some of the wires modified on it.

 

Let me google that for you

 

Yeah Franklin2...You must have read my mind as I have been reading up on 3g's online...Lot's of good info...seems as tho Ford led the way with 3g as they found out 2g's were causing fires...

I have thought about separating the running lights from the rest where you would have to turn them on via a toggle switch for some time now...I just haven't quite figured out how to do it yet and I am still studying how relays work etc...etc...I think I am close and hope to get it done during this winter while we are in Texas. My wife and I are really 5th wheel fulltimers now, but we have only spent 2 winters out from home...Once in Quartzsite, AZ, last year and this year in Ft. Worth, TX near relatives...

My truck is in really good shape now...left to do is paint and I have a spare 6.9 I am working on rebuilding so I can put on a turbo...it should be the last engine I need due to my age...

Anyway the block is at the machine shop getting hot tanked and checked and if good, will probably be bored no more than .030". I am thinking of having the new pistons (.030 over I hope) decked or shaved .020 or .030 for the turbo install but not sure if I should do that just yet...everything else will be stock with reman heads.

 

https://www.ford-trucks.com/forums/8...ml#post7434560

 

I did a quick look at the link above, and didn't see any links to relaying the running lights. I don't remember a discussion on it. I was thinking about doing it to my 89, and my first version in my head was to mount the relay under the dash on the driver's side, maybe near the top of the kickpanel. Then put a 20 amp circuit breaker on the battery +, and run a 12 gauge wire in through the firewall and feed the relay. The tricky part would be taking the headlight switch out, cutting the brown wire, and extended each cut end with a longer wire spliced in. The wire coming out of the headlight switch would go to the coil of the relay to trigger it, and the wire going into the harness to feed the lights would hook to the output of the relay.