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If it is a factory alternator, it should have the current rating stamped into the surface somewhere. If it is a rebuild (which I believe it to be) you have no idea what capacity it has, regardless of what is stamped into the case. During rebuild, they can marry-up any mixture of parts that will fit together.
If the alternator at one time was 61 A- that's the maximum output- usually around 2000-2500 RPM. Looks to be an aftermarket- so there's no idea if it puts out what it's suppose to.
First problem-Most of the time the fans turn on at idle- sitting in traffic AND the alternator is not going to be putting out anywhere near the maximum output.
Second problem- when the fans start up- they pull a tremendous amount of current- often double the rated consumption.
Third problem- your charging wire/harness was not designed to handle these amounts of current.
I'd do it right...replace the alternator and charging wire...
If the alternator at one time was 61 A- that's the maximum output- usually around 2000-2500 RPM. Looks to be an aftermarket- so there's no idea if it puts out what it's suppose to.
First problem-Most of the time the fans turn on at idle- sitting in traffic AND the alternator is not going to be putting out anywhere near the maximum output.
Second problem- when the fans start up- they pull a tremendous amount of current- often double the rated consumption.
Third problem- your charging wire/harness was not designed to handle these amounts of current.
I'd do it right...replace the alternator and charging wire...
Richard
Thanks for your feedback. Remember I'm not running A/A compresor so let's say the fans takes its Amp portion for now, so I'd use my current Alt just for testing the system.
Anyhow, I plan to replace the Alt just in case I finally decide to put the A/A compressor back.
Thanks for your feedback. Remember I'm not running A/A compresor so let's say the fans takes its Amp portion for now, so I'd use my current Alt just for testing the system.
Anyhow, I plan to replace the Alt just in case I finally decide to put the A/A compressor back.
Any recommendation about the charging wiring size?
No real difference not running the AC compressor. To engage the compressor doesn't require but just a small amount of DC power.
The 74 didn't have an electric fan for the condenser- and the blower fan is the same for non-AC equipped cars. Guessing GM thought you'd be running the AC in traffic at idle with the blower fan going- and a little bit of extra charge would help
I'd go with at least a 6 gauge wire from the Alt to the starter lug.
I'd wire the fan(s) to the starter lug as well.
Another problem- replacing the charging wire will make your ammeter read incorrectly. A voltmeter replacement will solve that problem.
I wouldn't use any kind of 10SI based alternator (this is the case type which was stock) for an application running electric fans. I would recommend you just step up to a CS144 (or the new improved AD244). It will keep the voltage steady at a slow idle with everything electrical in the car operating.
The charging wire to the solenoid has to be 6 gauge. I would run 6 gauge to a large terminal block where you can connect the fans and then continue it down to the solenoid.
Hook the voltage sensing wire for the alternator to this new terminal block.
Then, re-route the existing wire(s) which power the firewall plugs to this terminal block too.
No real difference not running the AC compressor. To engage the compressor doesn't require but just a small amount of DC power.
The 74 didn't have an electric fan for the condenser- and the blower fan is the same for non-AC equipped cars. Guessing GM thought you'd be running the AC in traffic at idle with the blower fan going- and a little bit of extra charge would help
I'd go with at least a 6 gauge wire from the Alt to the starter lug.
I'd wire the fan(s) to the starter lug as well.
Another problem- replacing the charging wire will make your ammeter read incorrectly. A voltmeter replacement will solve that problem.
Richard
Thanks Richard.
So based on your comments I don't have to change wiring from the battery to the Alternator, right?
What about if the fans are running with the engine off?, the battery would be feeding the fan or fans with a smaller cable.
Originally Posted by lionelhutz
I wouldn't use any kind of 10SI based alternator (this is the case type which was stock) for an application running electric fans. I would recommend you just step up to a CS144 (or the new improved AD244). It will keep the voltage steady at a slow idle with everything electrical in the car operating.
The charging wire to the solenoid has to be 6 gauge. I would run 6 gauge to a large terminal block where you can connect the fans and then continue it down to the solenoid.
Hook the voltage sensing wire for the alternator to this new terminal block.
Then, re-route the existing wire(s) which power the firewall plugs to this terminal block too.
I think this way is how my car is running now, I mean there is a terminal block in the middle of the Alternator - Starter line, and some other cables like MSD ignition ans firewall from there, but they are not definetly 6ga, I'd say 10 ga.
What I'm not able to find is where the hell ends up the positive cable from the battery, and that's a big one when leaving the battery.
So, upgrading up to 6ga from alternator to the terminal block and then to the starter would be the first step. Wiring both fans to the same terminal block with 10ga cable would be the 2nd step.
But I guess I cannot install a second 6 ga cable from the starter to the battery since I would be feeding with 12V the starter from 2 different sides (battery and Alternator)
BTW, can be these CS144 or AD244 alternators be purchased with V pulleys on it cheaper than $200 ?
So based on your comments I don't have to change wiring from the battery to the Alternator, right?
What about if the fans are running with the engine off?, the battery would be feeding the fan or fans with a smaller cable.
I think this way is how my car is running now, I mean there is a terminal block in the middle of the Alternator - Starter line, and some other cables like MSD ignition ans firewall from there, but they are not definetly 6ga, I'd say 10 ga.
What I'm not able to find is where the hell ends up the positive cable from the battery, and that's a big one when leaving the battery.
So, upgrading up to 6ga from alternator to the terminal block and then to the starter would be the first step. Wiring both fans to the same terminal block with 10ga cable would be the 2nd step.
But I guess I cannot install a second 6 ga cable from the starter to the battery since I would be feeding with 12V the starter from 2 different sides (battery and Alternator)
BTW, can be these CS144 or AD244 alternators be purchased with V pulleys on it cheaper than $200 ?
Well, I just saw where the positive cable from the battery ends up. Bubba thought that positive cables can be also black ones, so why using a red one when you have black available. One thing is true, it's a big one.
I just wrapped it a little bit with red tape to be clear, even though with that size is clear.
So now makes sense your recommendation.
Question is, should I replace the existing cable from Alt to the starter (PITA) or by adding a new 6ga one on the existing 10ga will be enough? In any case what are the fuses recommended for such installation?
Whatever you do, you still have to upgrade the power wire from the alternator. Your fans could draw 40-50 amps; so the alternator will be trying to replenish that amount when you are above idle. Putting a fuse or breaker in that line would only cause you to lose all electrical when the fans kicked on. I don't think that is what you want to happen.
Put in a BIG alternator and install a BIG power wire from it.
Question is, should I replace the existing cable from Alt to the starter (PITA) or by adding a new 6ga one on the existing 10ga will be enough? In any case what are the fuses recommended for such installation?
A bigger PITA is having to call a tow truck...
Yes- replace the cable and the alternator...
Here's a chart of why 6GU is a good idea- I used 8ft and 61A...
It's clear to me that Alternator an wiring need to be upgraded at this point.
What I meant by a possible solution is to keep the current installation and adding a paralel one with 6 ga wire and proper fuse, this way the voltage would dropped even less...maybe I'm wrong.
Otherwise unplugging the old one and adding a new one woth 6 ga wire may be another solution to keep the original harness just in case.
Now trying to find a good CS144 140A with V pulley
Alternator mistery denomination
