alternator or starter lug
 

Ok, so I am wiring in my new fan. My question is to clear up some of the research I have found. Some people say to power the fan off of the alternator lug (upgraded btw). Other people say to power it off of the starter lug. Now since I have put a jumper wire from the alternator to the starter lug already, wont hooking the fan to the starter be technically the same as hooking it to the alternator?

thanks,

Well to answer the question, connect the fan (thru a relay) to the alternator lug.
Now I got to ask, why did you put a jumper from the alternator to the starter?

doesnt the larger output of the alt require either a jumper or upgraded cable to function without burning something up? this way it can handle the load.

I did the same thing. I used a large wire that went from the starter to a junction block on the firewall near the starter. I then have smaller jumpers from that junction block going to the alternator, fans, headlights, and electric water pump. All (except for the alternator) with relays between them.

THE CORRECT answer IS....ALWAYS pull you heaviest current devices off the alternator stud direct, close as you can get....

leave the damn battery/starter post alone......

THAT is ONLY done for the signal portions of a fancy audio setup and the power amp is wired like above...across the alt....if you have a alt whine, buy a better amp.....

take that jumper from alt to battery outta there, as there is a fuse link in the factory wiring, it's a safety device in case of major shorts/accident in the wiring harness high current sections....
the sort of 'main breaker' if you will, like in your house most of the time.....older homes maybe not have that feature, but CARS do, always.....

In a word, NO.
The larger alternator will not burn out anything. What it does is simply provide more current capacity for any NEW or UPGRADED components you add aftermarket. It has no effect on the electrical stuff that was already there.
Now, if you put in big current sucking headlights, Fans, Amps etc and try to run that stuff thru your stock electrical harness you Will have problems.
Use relays to switch the power to these devices with the control side thru the stock harness, no problem, the relay coils use MUCH LESS current than the original components.
Like Gene says, yank out that jumper from the Alt to the starter, its a fire hazard and there is no reason to be jerking around with the charging and starter system.

thegazman
 

Did you install a fusible to the starter end of the new jumper wire. Most companies that sale you a larger size alternator recommend a larger wire to your battery cable on the starter or run an additonal wire with a fusible link. If you ran the "jumper wire" inside the wire loom and installed a fusible link it will okay. But, as these other guys said, If you don't have a fusible link you could have big problems if a short occurs. And where hook up fqans depends what's the best for. Try to keep as short ass possible, but fused for safety.

well thanks to those that actually answered the question about which lug to use.

for everyone else, i will reply to each person in turn.

wiring is not the issue, i have the relay thing worked out already.
the jumper wire to the alternator is there because if you search alternator upgrade, cs130 alternator, or cs144 alternator every single writeup and how to out there says to do it. You put a fusible link on the wire and connect the alt to the starter lug on the battery. this concept has been discussed a lot here so there is no need to rehash it.

yes it does, that is why i mentioned it was already done.

why do you say that because there is just as many posts here that say the starter lug with just as much enthusiam. hence my question, with just as many posts saying one or the other someone convince me with facts. oh and no need to curse.


this is the exact opposite of every single thing i have ever read here.
every write up here says to add a fused jumper wire from the alternator to the starter.

yep, i followed every write up here and they all said to use at least 10 gauge wire with a fuse. since you are supposed to go down 2 sizes with fusible links i put a 14 gauge fusible link on the alternator.
i dont understand why the people are saying now not to use one. where were these dissenting viewpoints when this write up was put out there. http://photos.imageevent.com/durango...%20Install.pdf


this is all the biggest issue i have ever seen here. you try to search around and do some research but you get one guy that says do it one way and another that says that the first guy is an idiot and things need to be done someway different. yet no one offers any proof one way or another. then you get someone trying to find out the truth and you cant get a definite answer to squat.

Actually, Spal recommends that the fans be hooked up to the battery to prevent spikes at the alternator. On the Corvette, the best place to do that is at the starter.

Basically constant loads are OK at the alternator (I have my lights hooked up to the alternator), but for loads that spike (like fans cycling and coming up to speed) the battery is the place to connect to. If the alternator was the place to connect, then GM would probably connect the main wiring harness there and not at the starter lug.

BTW, I have been researching adding electric fans to my 2003 truck and every harness connects to the battery, not the alternator.

I have an upgraded alternator and added a 4 ga charge wire with fusible link from the alternator to the battery. The battery has that big cable to the starter and that is where I get the fans feed.

Edit: Spal fan instructions http://www.spalusa.com/fans/automate...85FH-195FH.pdf

awesome man,
thats what i was looking for.

What size fuse do you use if adding a jumper wire. I too was told by many sources, (Spal, etc) to add a 10 guage jumper wire but didn't notice or wasn't told I needed to add a fuse. And should the fuse be near the starter or the alternator?

tie one end of the fuse link to the starter lug, and splice the wire that goes to the alt to it. that way, any shorts will immediately be stopped at the power source. the extra wire from the alt to the starter will by-pass any high battery charging currents that excessive cranking might impose on 35+ year old wiring.

Believe what you want, your car, I done too much ET and engineering design support over the years and I know what I said is correct, I have nothing more to say....simple as that....

I think your name is Brian Baskin....am I correct????

:lol:

NO it does NOT, look at a later wiring diagram, say like my '87 vette manual, you see the fuse link from the battery to the main power take off point, AS I REMEMBER, that is the terminal block right behind the battery there on the firewall area......

so when you look again at the GM wiring you find that fuse link is between the battery and ALL GM POWER APPARATUS, alt, fans, ALL of it.....take another look at the diagrams/flow charts and you see the FANS and all significant drains have their own fuse protection coming off the main power studs on the firewall.....

I seriously doubt you will find any factory wired vehicle with main power pulled off the battery directly....there are charging reasons for that to do with the battery, as well as obvious fire safety......

:lol::lol::smash::yesnod:

I see that Spal is using relays with their jumper off the battery, and of course a FUSE down close to the battery, I don't care for the diagram, due to the fan running is pulled through the fuse link wire and will drop charging voltage available to the battery and if the a/c is running constantly in summer time, the battery will never actually see full charging volts....always somewhat less....instead of 14.7 only maybe 13.7 or so....takes a longer time to charge the battery....symptom will be a perennially dead/weak battery......

I would think that a slo-blow circuit breaker would be the best thing to put into the fan circuit. That would allow you to "reset" it, should it ever trip. As far as what to do with original power wiring/fusible link when you upgrade the alternator and install more power draining equipment... of course, you have to upgrade them. Not doing so would merely have you replacing the existing fusible link every few days. DUH!

Look at the wiring diagrams guys, 6' and I have....

I"m outta here, you all believe what you want...


:lol: