Technical Power door lock wiring question

I need some guidance on wiring up some power locks. The inside switch works great. The outside switch is a Cole her see 75705-01 momentary keyed lock. When wired as attached and using the keyed switch will blow the fuse. I've tried several different configurations and it either doesn't work or blows the fuse.
Any ideas? Thanks

 

I'm guessing some relays may be involved. I like welding better than wiring.

 

I suspect you have the wrong type of key switch. If the interior switch is a 'reversing' type, a SPDT switch like you show won't work. Check the interior switch for continuity to ground; if the lock motor leads switch polarity when going from 'open' to 'closed', you'll need a 2PDT switch to make it work and a ground wire to the key switch. This could be done with relays too, but a switch will be simpler.

 

I suspect you are correct. The interior switch does reverse polarity. So, where should I go from here? I have not been able to find much in the way of a 2pdt keyed switch although I haven't looked a ton yet.

Would you do it with relays or know of a proper switch?

 

That's almost certainly what's going on. The notation about adding another switch causing a short is the key. This will still be a problem even with the right switch if both switches are operated at the same time. To do this 'right' with the switch you have, I'd use two 3PDT relays (two small 10A 'ice cube' relays should do it) and power the relays off the key switch you have. Have the relays disconnect power to the interior switch when operating the key switch; this will give a 'interlock' and prevent short circuiting it.

The OEM switches have this built-in, not so much the aftermarket stuff...

 

Thanks. Since the one outside will be used for locking up the car, they will not be used at the same time but I see how it "could" be a problem. I will take a look at it later this week. Hopefully I wont need you to draw me a picture.

 

In fact, if I were doing this with relays, I'd rewire the interior switch to also operate the relays rather than going directly to the motors; that will simplify the wiring somewhat and reduce the load on the switch. If you need a diagram, let me know...

 

Is that a 3 position key switch. you could run it to a pair of relay's which can be used to switch the polarity to lock / unlock, then hook the outputs from the relays in parallel to the 5 wire switch and install diodes to keep the power from feeding back and blowing a fuse. a bit complicated but it will work. if you are just using it to unlock the door, you can skip the relays and just install a pair of diodes in the wires to the inside switch so the power does not short out.

 

If you don't mind, that would be awesome. Thanks!

 

Here's the diagrams, there's two: one for the switches, one for the relays. Note that you don't want to connect the grounded wires at the interior switch.

 

Oh man, that's awesome. Thank you so much Crazy Steve!