# rad fan power for vacuum pump?



## dtbaker (Jan 5, 2008)

I am going to wire up my vacuum pump today, and am thinking that the old ICE fan wires would be good to use... already fused, etc. Is this a common source to power the vacuum pump for ya'll?


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## rich18325 (Aug 17, 2008)

You can use just about any key on circuit, the draw on the pump is very low. Under 4 amps on most pumps. You should have several to choose from. If you need wiring diagrams ,try looking them up on Autozone.com. Under their repair section they have a lot of full car diagrams.


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## dtbaker (Jan 5, 2008)

rich18325 said:


> You can use just about any key on circuit...wiring diagrams ,try looking them up on Autozone.com.


hhhmmmm, nothing online for suzuki swift, but there are some for geo metro '93 which are probably close at http://www.autozone.com/addVehicleI...pping/repairGuide.htm?pageId=0900c15280048a35

The windshield washer is very handy to where my vac pump is located, I am just a little afraid of blowing th fuse if the pump comes on while wipers are on high.... But, I may just tap into that if I cant run something from the radiator fan circuit. thanks!


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## tj4fa (May 25, 2008)

dtbaker said:


> I am going to wire up my vacuum pump today, and am thinking that the old ICE fan wires would be good to use... already fused, etc. Is this a common source to power the vacuum pump for ya'll?


Nope...see my post to your "wiring square D vac sensor to vac pump" thread.


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## Hondacrzy (Mar 15, 2008)

That is exactly what I did. My pump sits in the right front corner of my engine compartment and there is the connector for my cooling fan right there. I taped into the ground input from my fan switch and works like a charm. Very little extra wiring.


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## dtbaker (Jan 5, 2008)

tj4fa said:


> Nope...see my post to your "wiring square D vac sensor to vac pump" thread.


I missed that thread early... nice one by the way. The details on switch wiring are great. Interesting that several people now echo running the + red thru the switch, instead of black- as shown in my KTA schematic.... got me wondering now. ah well.

I didn't see anything about why NOT to use the radiator fan power to run the vacuum pump.

Bad news is that the vacuum pump (brand new) seems to be dead even with direct jumpers to spare 12v battery. ;(


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## tj4fa (May 25, 2008)

dtbaker said:


> I missed that thread early... nice one by the way. The details on switch wiring are great. Interesting that several people now echo running the + red thru the switch, instead of black- as shown in my KTA schematic.... got me wondering now. ah well.
> 
> I didn't see anything about why NOT to use the radiator fan power to run the vacuum pump.
> 
> Bad news is that the vacuum pump (brand new) seems to be dead even with direct jumpers to spare 12v battery. ;(


Breaking the ground side for the Vswitch should still work as it completes a circuit but doesn't make sense to me. The fuse in the positive side should protect both the wiring and the pump.

I used the fuse block on the control board for the new circuits to make things simpler. Most of the other devices on the control board only take a few inches of wiring and a couple feet at most.

The grounds to these circuits also connect under the board on a common ground point (a bolt/nut through top the bottom of the control board) and then a single wire run to the truck body.

I've seen some conversions where the wiring looks like spaghetti all over the place.










--- 
As far as tapping into your radiator switch circuit you will probably be ok but I would make sure the fuse is de-rated to protect the Vpump motor. The old ICE radiator fan/wiring may have pulled a lot of amps (maybe even have a relay somewhere in the circuit) and have a bigger fuse than now needed which may not "blow" or blow fast enough to protect your Vpump.
---

Too bad about your Vpump.  Your vendor should send you a replacement, but it sux to have to wait for a replacement to show up. Better it failed up front than to give up the ghost when you really needed it.


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## dtbaker (Jan 5, 2008)

tj4fa said:


> I used the fuse block on the control board for the new circuits to make things simpler. Most of the other devices on the control board only take a few inches of wiring and a couple feet at most.


ok, I am leaning your direction.... better to have a clean new run with known fuse off my control board than dissect the ICE wiring harness and run a wire around the whole engine bay.

I think I am also going to go with red + thru the switch

....so I'll be removing and returning the &%$^$ vacuum pump before working on my rear battery rack today.


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## tj4fa (May 25, 2008)

dtbaker said:


> ok, I am leaning your direction.... better to have a clean new run with known fuse off my control board than dissect the ICE wiring harness and run a wire around the whole engine bay.
> 
> I think I am also going to go with red + thru the switch
> 
> ....so I'll be removing and returning the &%$^$ vacuum pump before working on my rear battery rack today.


Glad to see your Vaccum pump is working again. Who'da thought the rear mounting screw you put in was too long binding up the piston from working.

How's the noise and vibration from the pump?


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## dtbaker (Jan 5, 2008)

tj4fa said:


> Glad to see your Vaccum pump is working again. Who'da thought the rear mounting screw you put in was too long binding up the piston from working.


pretty good guess, huh?! As I was leaning over the traction motor looking directly down into the lift-bolt hole that goes thru the motor case, I thought to myself 'I wonder what happens if you put too long a bolt in there to cover the hole? Got me thinking about the vacuum motor, so I tested before I had removed the whole dang thing.



tj4fa said:


> How's the noise and vibration from the pump?


Its not bad at all... little compressor noise, and no vibration makes it into the cabin at all. BUT no matter how much I fiddle with the adjustment on the switch it doesn't want to pull more than -15inHg. It doesn't seem to be leaking once it cuts out, but it really slows down between -12 and -15inHg, so I set it to cut out at -14inHg.

Normal? bad?, any suggestions?


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## tj4fa (May 25, 2008)

dtbaker said:


> ...no matter how much I fiddle with the adjustment on the switch it doesn't want to pull more than -15inHg. It doesn't seem to be leaking once it cuts out, but it really slows down between -12 and -15inHg, so I set it to cut out at -14inHg.
> 
> Normal? bad?, any suggestions?


Not normal I think...

My Square D switch goes up to 25in Hg. The switch directions says it sets both cut-in and cut-out settings at the same time (5 inches difference between the two on mine) so I only adjusted the self-locking nut on the larger threaded adjuster.

EVA instructions says they set the switch to shut of at 20 inches and restart at 15 inches. They say a tight vacuum system can maintain vacuum for 2-4 minutes. 

I set my cut in point higher at 19.

Did you put hose clamps on all the hose connections? A tiny leak will run down the vacuum pretty quick.

I would recommend you take off your hoses back to the T fitting and only have the Vpump, switch, and vacuum gauge hooked up and then see what you get and try to adjust it there. Maybe your reservoir (if you have one) and your brake booster have a leak and won't let you get up to full vacuum at 25in Hg.

My ICE brake booster and check valve were bad and I had to change it out. A one way check valve in line before your reservoir and brake booster might help as well.


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## dtbaker (Jan 5, 2008)

tj4fa said:


> Not normal I think...
> Did you put hose clamps on all the hose connections? A tiny leak will run down the vacuum pretty quick.


system holds vacuum with no loss for hours so far.... It's been sitting at -14 since this afternoon when I left it. So the system is tight at least back to the one-way check valve. ALL fittings have pipe dope and hose clamps.

When I mess with the upper range, and move it past 15 or so, the pump just continues running and the movement on the gauge really slows down at -13 or so. I guess I could have a leak somewhere south of the check valve, or a bad seal in the pump?

A pretty good picture of the vac plumbing is at
http://envirokarma.org/ev/gallery/080723_03.vComplete.htm


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## tj4fa (May 25, 2008)

I initially set the pressures off the vehicle with only having the pump and switch hoses hooked up and a vacuum gauge stuck in the hose at the T where the vacuum reservoir would later be connected.

Then I added components one at a time and re-checked for leaking and pressures as I went.

Since EVA said to set the restart pressure at 15 and cu off at 20, I'd recommend to at least give them a try if you can.

It could be possible your Vswitch diaphram might have the seal a little out as you had to remove and reinstall screws for the mounting bracket. You might want to check and see if the diaphram might be a little distorted.

Also I sent you a PM and e-mail with some Suzuki schematics to your envirokarma website contact e-mail address.


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## dtbaker (Jan 5, 2008)

THANX for the schematics, I may put them up on my website for any other swift owners to use... where did you get them?

I guess I'll go back thru the conections post-checkvalve first... The system held its measly -14 inHg overnight with no loss at all, so I don't wanna mess with anything upstream if I can help it. I wish I had a second gauge I could hook directly to pump to see if it pulls the vacuum, or if I have a leak. Ah well, only two connections to check...


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## chamilun (Jun 17, 2008)

I would wait for normal driving testing to see if the number is important. In fact, I have no idea what my switch is set at. Even though I have a vacuum guage, I actually did not use it. 

My vacuum pump just ran and ran when first connected. After being reasonably certain that I have no leaks (minimized hose lengths, made exact holes for the barbed connections, proper clamps), I let the pump run for a few minutes, then adjusted the switch until it shut off. The car has excellent braking. I am using a 12x2" PVC container as a reservoir, which is about 1/2 the size it should be, but I was concerned about where to place either two containers this size or one 2ft piece.


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## dtbaker (Jan 5, 2008)

chamilun said:


> I would wait for normal driving testing to see if the number is important. ...
> My vacuum pump just ran and ran when first connected. After being reasonably certain that I have no leaks ...I let the pump run for a few minutes, then adjusted the switch until it shut off. The car has excellent braking.


sounds good to me. I just re-sealed my two connections downstream of the check valve, with no improvement. It takes 25 seconds for the pump to get from -10 to -14, at which point it really has trouble getting much lower. I think I may just leave it be and see how it drives....


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## dtbaker (Jan 5, 2008)

just a followup on this.... After talking with Gast tech support, turns out that these pumps are basically re-rated by about 1 inHg per 1000' ft of elevation. So, -13 or -15 is the best I can EXPECT where I live. I set to -13 so that it doesn't run for a long time trying to get that last little bit.


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## piotrsko (Dec 9, 2007)

the Old man reason for NOT running the red wire through the switch:

many eons ago, when vacuum tubes and spark oscillators ruled the world, EE's discovered that for some reason (sorry, I used to know why) the DPd/sT switches hardly ever arced on the return (or ground) side of the switch. In all the really old cars, the vehicle is either positive ground, or the switches are on the ground side of the load. Distributors are still wired that way to this day, points breaking the ground side..

does it make a difference today?? Idunno, but given a choice, I break the ground.


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## dtbaker (Jan 5, 2008)

piotrsko said:


> the Old man reason for NOT running the red wire through the switch:
> 
> many eons ago, when vacuum tubes and spark oscillators ruled the world, EE's discovered that for some reason (sorry, I used to know why) the DPd/sT switches hardly ever arced on the return (or ground) side of the switch. In all the really old cars, the vehicle is either positive ground, or the switches are on the ground side of the load. Distributors are still wired that way to this day, points breaking the ground side..
> 
> does it make a difference today?? Idunno, but given a choice, I break the ground.


THAT is interesting?!
So, why did Lucas Electrics get such a bad name; positive grounds and all.... ? I had an old car that was all 'bullet' connectors, was that the problem?


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