# wiring square D vac sensor to vac pump



## e_canuck (May 8, 2008)

dtbaker said:


> ...working on vacumm pump wiring today. My schematic from KTA shows very simple fused 12v+ in to gast vac pump red wire, then vac pump black to square D diff vac switch, then out to 12v 'return'.
> 
> Confusion for the non-e sets in when I removed the cover of the switch to hook it up, and there are four possible connections left to right L1, T1, T2, L2. When I look at square D instruction sheet, THEIR schematic is different with the vac motor leads both coming to the switch T1, T2 and not labelled + or - or black or red.
> 
> ...


Hello dtbaker.

I took out my diagrams and my own switch to see.

The vacuum switch is actualy two independent switches.

If you look at the contacts with the hose connection away from you.

The left switch as terminals labeled L2 and T2.
The right switch as terminals labeled T1 and L1.

You need to use the left ones or the right ones.

On my diagram from EVA ( fig 4.5-1 ):

the black wire from the pump goes to ground,
the red wire goes to T1,
another wire ( presumably red ) come from 12v+ is fused and then goes to L1.

I played with the switch and at rest the switch makes contact. So L1 and T1 are conected.

If you move the "plaque with the pushrods" underneat you can see them breaking the contacts. A fact confirmed with my multimeter.

So when that will move ( with the vacuum ) L1 and T1 will be disconnected.

You will also need to use a green wire to ground the box, incase a wire should go loose and contact the sides.

Hope I was clear enough and you found this usefull.

Take care,

DP


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## dtbaker (Jan 5, 2008)

e_canuck said:


> On my diagram from EVA ( fig 4.5-1 ):
> the black wire from the pump goes to ground,
> the red wire goes to T1,
> another wire ( presumably red ) come from 12v+ is fused and then goes to L1.
> ...


great, thanks... I am on the right track although I find it interesting that KTA schematic puts the 12+ direct to the pump, and the neg back thru the switch. Wonder why? Any pros/cons to wiring the pos thru the switch versus the neg thru the switch?

Anyway, I tried this and powered direct to a spare 12v battery... no go?! I tried to power the vac pump direct from 12v battery, and still no go, so I guess I have a DOA vac pump!!! crap. I sure hope I can exchange, and I am peeved that I now have to remove and re-install the pump. Better now than later I guess.

Anybody have anything I can check on the vacuum pump as to why its dead before I try to exchange it?

Only positive thing today is that I made the A2-S2 cable today, and powered the motor directly from 12v battery while on jacks and in 2nd gear for a quick spin test for the first time. Things went pretty smoothly and in the right direction, although I wish I could feel someone else's motor turning for comparison. I have a little vibration, but not much, I'm just wondering if its 'normal' if if it should be perfectly smooth if tranny adaptor is perfectly aligned and balanced.


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## e_canuck (May 8, 2008)

dtbaker said:


> great, thanks... I am on the right track although I find it interesting that KTA schematic puts the 12+ direct to the pump, and the neg back thru the switch. Wonder why? Any pros/cons to wiring the pos thru the switch versus the neg thru the switch?
> 
> Anyway, I tried this and powered direct to a spare 12v battery... no go?! I tried to power the vac pump direct from 12v battery, and still no go, so I guess I have a DOA vac pump!!! crap. I sure hope I can exchange, and I am peeved that I now have to remove and re-install the pump. Better now than later I guess.
> 
> ...


Hi Dan.

I tought we had the same pump and switch. Now I am not so sure. We probably do but mine worked on first try with a battery. There is almost no parts for it to go bad. Bummer those things are expensive.

I do not know what you can check on those pump exept measuring the resistance between the red and black wire with a multimeter. Mine is zero.

You connected the pump directly to a battery? or trough a fuse?

Usualy the switch is placed on the live side ( red ) so a device that looks off will stay that way if you should groung it with your fingers. Save you from a shock too.

Congratulation on a successfull first spin. I am no where near that.

I think everybody freak a bit when those things are powered. We expect nothing and we expect smoke at the same time.

Maybe someone will chime in with some better advice.

Good luck,

DP


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## tj4fa (May 25, 2008)

Hi Dt,

Way to go on your first spin up!

Vaccum pump test - Touch the red wire of the pump to the positive post of a good 6 or 12V battery. Touch the black wire to the negative post. The vacuum pump should run (just slower with a 6V battery). If it don't pump, send it back.

---
Here's how I did the wiring of some of the new 12V devices of my Ranger.

I bought a 6 circuit fuse block from Autozone that uses the little plastic fuses. I fused all the new devices like the vacuum pump with 10A fuses. 

This block simplifies all the new 12V wiring.

The two-fuse block to the right rear is the fuseblock for the 144V ammeter and voltmeter.











A wire that is hot off the ignition key switch powers the new fuse board. I used 14ga wire for all my new circuits like Controller fan, BK Vpump, KSI relay, Inertia Sw, contactor 12V input ect. You could use 16ga wire as well.

For the Brake Pump

-Key switch 12V (hot with key in run) ----> New fuse board. 
-Fuse #BK wire----->L1 of of Vswitch.
-Connect red wire of Vpump to T1 of Vswitch.
-Connect ground wire from Vswitch gnd terminal (green screw) to Black wire of Vpump (I used black wire to keep with automotive color code for grnd)
-Tie ground wires together and ground them to body or frame at most convenient point.

---

As far as your vibration, it could be tire/wheels out of balance but could be a misalignment of motor/transmission/driveshaft.

You might be able to rule the tires/wheels out by removing them and re-installing the brake drums and snug up all the lug nuts. If the vibration lessens, then they may be out of balance.

If it's still there, remember you haven't put grease in your transmission yet or you may have a driveline misalignment. 

The first time I put in my transmission crossmember, I had it facing backwards and didn't see the "front->" arrow. 

I still wonder if I'm totally "true" on my driveline as I get an occasional "judder" (3X and then ok) between 25 and 30mph when I'm hard on the accelerator.


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## dtbaker (Jan 5, 2008)

tj4fa said:


> Vaccum pump test - Touch the red wire of the pump to the positive post of a good 6 or 12V battery. Touch the black wire to the negative post. The vacuum pump should run


DANG... I have a dead one! Now I have to de-install and beg for replacement ;( Well, the lesson is to bench test these before install I guess.




tj4fa said:


> Here's how I did the wiring of some of the new 12V devices of my Ranger.


nicely done! I am planning similar except using the bus fuses. Still have to find the silly switched 12v wire from ignition though.



tj4fa said:


> For the Brake Pump
> 
> -Key switch 12V (hot with key in run) ----> New fuse board.
> -Fuse #BK wire----->L1 of of Vswitch.
> ...


hhhmmm, you are the second for red-to-switch. Perhaps I will go that way instead of KTA schematic, make sense....




tj4fa said:


> As far as your vibration,
> If it's still there, remember you haven't put grease in your transmission yet or you may have a driveline misalignment.


Its not 'much', so I wondering if it 'normal'. I just drained and filled tranny with royal purple, so that should be good. The vibration is barely visible, just a 'buzz' jiggling maybe 1/16 of inch. I can't think of any way driveline could be misaligned ... only thing is perhaps the cover of the clutch plate may not have gotten re-assembled in the exact orientation it was, and may be out of balance. I wonder how bad that would feel?


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