12V switch power needed

[Phils69 27]

I am installing a vacumm pump for my brake booster due to a big roller cam pulling only 5.5" vacumm at idle. The kit I got comes with a relay and fuse and it needs a 8 to 10 amp key switch power circuit. What would be the best way to tie into a existing circuit? Or should I run a new power wire off the fuse block but then how would I tie it into the key on curcuit? Any ideas appreciated.

[69gmachine 15]

You can tie it into the radio power, a yellow wire with black stripe.

[LoneWolf2U 136]

Use the fused wire off the main batt term to power relay to the pump.

The switched source wire can come off of the fuse panel for key on power to the relay.

[Phils69 27]

Thanks guys. I'll tackle it this weekend and see how it goes.

[danno 128]

Like Mach1 mentioned, the fused wire can come right off your battery, a good place is where the + wire connects to the starter relay. The switched source, though, cannot come from a fuse in the fuse block. Not one of those fuses only has voltage on it when the key is in the run position. They either have voltage on them all the time (like for lights) or when the key is in the ACCY position. If you want to keep all the wires under the hood, one of the wires to the voltage regulator has voltage to it only when the key is in the run posistion. It should be a violet color wire.

[Phils69 27]

Let me get this straight. I could pull the fuse wire from the battery side of the starter relay. Pull the key on power from the violet wire from the relay. I would have to add another relay to do this. Can I pick one up from a major parts store?

[Phils69 27]

They relay I have only has the fuse power key on wire pigtailed to the motor wire. The relay is used for toggling on and off the pump when a vacumm pressure switch tells it to.

[danno 128]

I think you misunderstood what I was saying. Your vacuum motor has 2 wires to it and a ground ( maybe a ground wire?). One of the wires has a fuse in it, and this is what your motor gets it's voltage from when the key is on and the relay is ON. The relay gets turned on only when the key is in the run position, and this is what is on the violet wire. So the wire to your pump that normally would go to the key switch (for power only when the key is on), this wire should connect to the violet wire on your regulator.

[danno 128]

Oh, I did not see your second post. Now I understand. I am wondering if you can break the pigtail connection? Then you will have the 2 wires we were thinking you have. Either that or get another seperate relay to turn it on only when the key is in the RUN position.

[Phils69 27]

The relay with the kit has 4 connections on it. One to the pressure switch, one that requires the 12v key on power that energizes the switch and also pigtails to go to the positive terminal on motor, one to ground and one to neg terminal on motor. I'm thinking it would be best to add a relay to supply the 12v key on using the violet wire you spoke of and pulling power from the battery side of the starter relay. Think that shoud work?

[LoneWolf2U 136]

Can you post a pic of what you have or somewhere to see what your using?

I think your making it more difficult than it should be.

[Phils69 27]

If I had known the manual was online I would have started with that. The links are below. Let me know if they dont work.

 

pump: http://www.summitracing.com/parts/CCA-5500/

 

manual link: http://www.compcams.com/Instructions/Files/COMP4-110.pdf

[LoneWolf2U 136]

No fond of their wiring set up, but you could try using the backup light black/red wire as your key on + source. It is 14 amp fused wire with wipers.

 

I would install another relay for the power lead for the pump relay and use the backup light wire to supply the key on source to switch it on.

[Phils69 27]

Sounds like a plan. Hopefully Auto Zone or Advance has a relay and I'll get this thing running by Sunday. Or stopping I guess I should say. Thanks

[danno 128]

That idea should work, but you will be turning on the pump whenever the key is in the RUN or ACCY position. I like to turn on my car radio when I am working in the garage, so I put turn the key to the ACCY position to do this. If you do this, you will be running the vacuum pump. If you are not driving the car, then it will not be running much. Just something to consider; do you want the pump on whenever the key is in the ACCY position?

[Phils69 27]

I'm planning on pulling the power from the pump from the battery side of the starter solenoid. I'll pull the key on 12v to trigger the relay to turn the power on from either the violet wire on the starter solenoid or the electric choke. Thefts the plan anyway we will have to see how it goes.

[Phils69 27]

Well I'm having issues. Got everything hooked up and it's not turning the pump on. I got a good ground going into the relay and 12volts going to the vacumm motor. What it is missing is the ground signal going from the relay to the pump which I am assuming because the vacumm switch is not making the signal to turn the negative terminal to pump on in the relay. Is there a way I can check the switch? It's not showing any voltage going to the vacumm switch from the relay. Should it or does the 12 volt only come on when the switch makes?

[Phils69 27]

Here is some more info

 

I have installed and wired the pump in the links below but it's not working. I'm getting 12v positive to the motor but no negative. I have installed an extra relay to supply the 12v needed from the battery. My connections are as below. Please take a look and see if anything is not hooked up corrects. Thanks

 

Added relay. This relay looks like it is functioning as should. Only supplies the 12v key on power out of pin 87 when the key is on.

 

Pin 30: straight from battery positive with an inline fuse

Pin 85: to chassis ground

Pin 86: 12v key on power only

Pin 87: to relay pin b in kit.

 

Kit relay

Pin B: has the 12v supply power from pin 87 on the added relay. The 12v positive has a connection between these two pins to go to motor positive. I have the required 12 volts to the motor.

Pin C: to chassis ground

Pin D: goes to neg side of motor. I have NO Negative going to the motor which is the issue.

Pin A: has one wire connecting here from the vacumm switch. When I check this wire it is grounded. Is this correct? I'm thinking it should be grounded when the pump needs to come on. I can unplug this and it makes no difference.

 

The pump does function as I have supplied a temporary ground to it with all the other connections made but runs continuously as it does not have the switch to turn on and off the ground. I'm assuming the kit relay works as my other one with the terminals matching as follows:

 

Think it's wired correctly. Bad relay?

 

 

 

 

 

 

http://www.summitracing.com/parts/CCA-5500/

 

 

http://www.compcams.com/Instructions/Files/COMP4-110.pdf

[LoneWolf2U 136]

You answered your own question.

Pump runs with temp ground. Follow the path to ground needed to make it run, The switch is next inline. Check the switch for proper connection,grounding and function.

[Phils69 27]

Got it. Turns out their relay was bad. Thanks for the help

[Phils69 27]

Update. The switch was bad also. I ordered a new switch, same kind that came with the kit. I hooked it up yesterday and it worked, switched pump on at 15 and cut it off at 22. I went for a test ride today and it was pumping up only to 5 and cutting the pump off. I'm kind of wondering if it's something with the wiring that's causing the switch to go bad but I dont see it. The switch is closed and sends a neg ground to relay when it is below the vacuum set point. Once the vacuum required is met the switch opens and breaks the negative ground ,cutting the path for the pump neg ground. I have it wired just like I posted before with the two relays. Do you guys see anything not right here or am just getting some bad switches? I came across an electric vehicle forum on my many google searches about this and most there seem to use a Square D commercial switch which is quite expensive. I disconnected the pump today and installed a vacuum canister and it's working quite well. It loses the power assist sitting at a stoplight but during normal brake application it works good. I'd like to get the switch working but one more bad switch and I'm going to return this kit to sender. Any ideas?

[danno 128]

I am not sure if this has been discussed, but does the pressure switch only have one place to connect a wire? If that is the case, it needs to be screwed to a gound connection. Does the pump turn on and stay on when you connect the wire that goes from the relay to the switch? It should, and should give you plenty of vacuum.

 

It is also possible you have the switch supplying the ground to the motor, not the ground on the relay. Try what I suggested above; connect the wire from the relay to the switch to ground so the pump is on all the time. Then disconnect the wire from the relay to ground. If your motor keeps running, you have the relay wired wrong.

 

It is possible the switch was wired wrong at first, and that might have damaged it.

[Phils69 27]

The switch only has one connection on it and it is screwed to the chassis directly with the engine ground harness. If I disconnect the switch from the relay and hook that relay point to a ground it runs continuously. The switch is trying to work as it should just pumping to 5 hg of vacuum instead of 22. I have triple checked the wiring but it just looks like another bad switch. I've ordered a different brand of switch this time and will try it when it get here.

[danno 128]

A second bad switch is suspicious. I would contact the manufacturer and see if they can do anything, if it is the switch they have had other problems with this probably. Maybe a google search in other high performance forums would show others have had the same problem with this product?

 

It sounds like you are on top of the problem, good luck.

[Phils69 27]

i have googled and have found a few people with faulty switches. One guy took one apart and said it very cheaply made. it looks like people ditch the switch from the kit and add a better one. I have one on the way from an electric vehicle parts supplier and will try it next week. I have called Comp on the issue and they say to return the whole kit for an exchange. I dont want to tear it all back out just for the switch. If it is something else that is the issue I am stumped. Its a simple relay working it. Power goes in and energizes the switch which closes the contact to conect the neg from the switch to the motor negative. its getting the power to the relay and the relay is energizing showing continuity between the switch input and pump negative output so I am sure the relay is working. It's gotta be the switch as far as I can tell. I will post the results whe I get the next switch in. Thanks