Vacuum pump wiring question ?????

[KnuckleDuster]

Ok,I have a (GM)Delco vacuum pump,like SSB used to sell.The positive and negative I get.Trying to figure out where to wire in to the ignition so it only gets power when the key is on.

So far I've tried wiring it to the top post on the starter relay...it comes on,shuts off,then comes back on again,whether the key is on or not.
I have a fresh rebuilt booster,so does this mean the booster is bad?
I am not very experienced with wiring,am I just missing something here?

Thanks!

 

[67Dart273]

I don't know anything about those pumps, but the stud on your starter relay is full time battery

Is it possible that they have a pressure switch to shut them off when they pump down?

The ONLY switched power under the hood is ignition power (the "dark blue" "run" wire, and you should not load it more than it already is, and besides, it is NOT fused.

Hook a relay to the starter relay stud, with a fuse to run the pump, and use the blue IGN lead to trigger the relay.

In fact, I use relays for both the fuel pump and ignition on mine.

You might want to read this:

http://www.gmcmotorhome.com/tech/vacuum_pump/index.html

 

[KnuckleDuster]

I do have a fuse on the positive wire for the pump,would this allow me to tap into the blue wire without hurting anything?

If not what kind of relay should I use,a part number would be awesome if you know.

Yes I believe the pump does have a switch to kick it back in when vacuum drops,which is why I'm worried about my booster.

Thanks,still trying to get my head around this a little bit,I hate electrical...

 

[67Dart273]

Check that link I posted, you may have all you need "built into" the pump. Can you post some info on the pump, or confirm or not whether it's similar to that link?

 

[KnuckleDuster]

It's the same pump.

I ran wire into the dash and tapped into the 'key on' ignition wire where I had spliced in my MSD...(brown I think,maybe blue,I would have to check in the morning)it seems to be working fine.

...now if I could just get my horns to work...

One came with the car,the other I pulled out of an 86 Ramcharger ,so I doubt they are both bad.

The relay is making a sort of springy clicking sound when I press the button.
Does that mean it's working or does that mean it's shot?
I know it's original because I was the first to dig into the insulation to find the mounting bolt.

I traced the wiring and couldn't find anything obviously wrong.

Any help would be much appreciated,I would like to get it inspected this week and it won't pass if it won't blow.

Thanks again!

 

[67Dart273]

Sorry, I'm really not familiar with those pumps. Is it possible that it's pumped down to pressure? IF the hoses are hooked up, remove the intake hose to relieve the pressure and see if it fires.