Only I could ask this right. This is the last paragraph of another thread, copied over here for wider exposure of my ignorance.

So here is the really basic, Dumb-dumb question: If pin 30 and 85 (of a standard auto relay), both are wired for a 12+ switched voltage, is there any reason you cannot simply jumper the two together. Am I going to create some kind of unexpected feed back monster here? It seems as if jumping them together would be the same as running a seperate wire out to the same source.

This is just a basic practice question, not related specifically to the other thread.

Sam

_________________

Sam
Im not familiar with the relay. However in practice if its the same electrical point then you can jumper or wire it either one.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

Isn't one of them switched and the other directly to the batt + terminal?

That would be a problem since some or all of your switched power will now be drawn directly from batt +. You may not be able to turn the car off...

Lou

_________________
Home of Slant6-powered fun machines since 1988

Pin 30 is the 12v supply. pin 87 is the load device. Pin 86 is the 12v supply for the relay coil. Pin 85 is the ground for the relay coil.
So yes you can use the same 12v supply wire to pins 30 and 85. In this case you would switch the ground wire on pin 86 to turn the relay on and off.
Now for the caveat: this is for a non suppressed relay and or resistor suppressor relay. These relays are non polarized.
If the relay has a diode suppressor, pins 85 and 86 must wired as stated.
PS: Pin 87 is the normally open terminal of the relay, and Pin 87a is the normally closed contact, with respect to Pin 30

Edit: 7-27-08: Corrected the pin polarity for pins 85 and 86.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks Charlie, that was a great help.

Sam

_________________

Some additional resources you may want to look at to familiarise yourself with projects like this:

My headlamp relay page

DIN terminal designations, including all terminal designations you'll find on relays.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan. I read through that, and printed it out as a keeper. The challenge on this end is largely hardware related. I can get relays easily, but cannot get prewired relay sockets of the type that would be wired into harnesses. I can get sockets from CH that have no wires. You provide the spade connectors, and those I have found don;t fit the plastic socket holes in the CH base.

I had controlled both the fans and headlights with a bulky old Geo realy/fusebox I had cut out of a junk car. It is time for it to go. The fan section is already rewired with two new relays I purchased from my local John Deer tractor dealer. These John Deere Relays have a recessed contact section, and a metal mounting tab, so they were easily mounted on the radiator core support. The design allows the connectors to be hidden up inside the relay cover, where they are safer, and look better. I still covered the entire spade terminal with shrink wrap tubing just to be on the paranoid side.

I now wish to finish off the Geo fuse box, and get it out of the engine bay, but it is Sunday, and have no more John Deer relays. I will look on your web site and see if I can find something that might work.

On a related subject, I have a Batt+ buss bar that is exposed and wish to cover it with something to protect it from stray wrenches and such. I guess I could use rubber vacuum nipple covers which would protect most of it, but it would be nice to covre the entire thing. I was thinking fo going to the local CVS and just looking around for something plastic that I could cannibalize.

I thought it was interesting that your wire colors in the diagrams were pretty close to the Mopar colors. Is Violet universally the low beam color across the auto industry? Your highbeam color was close, if not exact.

Sam

_________________

I am swimming in them. Nice ones that dovetail together to create tidy relay banks of however many relays you want, now and/or later. Well, OK, actually my warehouse manager is swimming in them. Got your PM, will reply when I get back to the house (I'm over at the office feeding the plants and watering the cats).
Nope, there aren't any universal colours...I made that diagram many years ago on a program called MacPaint that was obsolete even then. Picked out the colours randomly.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks man. It is starting to storm here, and may shut down the computer till the storm passes.

Sam

_________________