This question is about a five wire relay. With a single pole and dual throw. Can I twist the 2 output wires together into one to power output?

This question is about a five wire relay. With a single pole and dual throw. Can I twist the 2 output wires together into one to power output?

SPDT would never shut off if you did that.
You could do it with a DPST

What causes it not to shut off? Its got a power in, an acc. turn on lead in, a ground, and two power outputs. I am trying to use it to turn on an electric fan.

just use one of the power outlets for your fan and cover or clip the extra outlet as needed.

I was lookin into getting some relays off of ebay. All I could seem to find was this five wire kind. They are similar to those on my headlight harness I bought from SUVlights.com. If I cound find some with less wires, that would be great.

What causes it not to shut off? Its got a power in, an acc. turn on lead in, a ground, and two power outputs. I am trying to use it to turn on an electric fan.

As you can see by the dotted red line, the operation of the reay can not make any difference one way or the other if the two outputs are connected together.
You would need a DPST or DPDT to double the amprege rating of the contacts.
(assumng that both sets of contacts make and break at the same exact split second)

Like Dean's diagram shows.... most 5 pin relays have 2 outputs - Normally open, and normally closed.

You can use these relays to open a circuit, or close a circuit. But if you tie the outputs together, you will simply bypass the contacts of the relay, and whatever you hook to it will always be on.

The center pin is the normally closed one. :)

I've seen some 5 terminal relays where there were 2 output terminals as you kind of suggested. They are just a normally open contact relay with 2 terminals on the one contact instead of 1 terminal. You could use 1 of the terminals or both as it suits the wiring scheme without any difference on this type of relay.

Peter

I've seen some 5 terminal relays where there were 2 output terminals as you kind of suggested. They are just a normally open contact relay with 2 terminals on the one contact instead of 1 terminal. You could use 1 of the terminals or both as it suits the wiring scheme without any difference on this type of relay.
Peter
Hella part# 87453 40amp SPST w/dual 87 contacts

Thanks everyone!

I posted this awhile ago, great link at the bottom:

http://www.chevelles.com/forums/showthread.php?t=117758&highlight=relay

What type of relay would I need to use to get this final result, and how would I need to wire it?:

Two inputs (either + or - signal from sensor or sending unit) one output to the device. A switched power or ground in to activate output to convey one input or the other.

Does it matter if the signal in question is positive or negative?

I am trying to use it to turn on an electric fan.
What type of relay would I need to use to get this final result, and how would I need to wire it?:

Just a standard SPST relay. For fans, most of the time the ground is broken, used as the switch to turn the relay on and off, usually through a temp sender to ground although there are others. The type of sender you are using will determine how the relay is wired. A fan can be wired to turn on automatically, manually or a combo of the two, just depends on what you want.

http://www.chevelles.com/showroom/data/500/medium/1098relay.jpg

The second situation I asked about was not for a fan application. I have a painless relay on the dual fans on my chevelle that turns them on automatically at 170. Im using a relay on my nissan to turn on the electric fan whenever the motor is running with an override switch on the dash. What I was also wondering about is using relays to piggy back and trick my ECU. By splitting a signal wire from a sensor into two wires, one with a resistor. Having only one of the two reaching the destination controlled by a switch.

Im using a relay on my nissan to turn on the electric fan whenever the motor is running with an override switch on the dash. What I was also wondering about is using relays to piggy back and trick my ECU. By splitting a signal wire from a sensor into two wires, one with a resistor. Having only one of the two reaching the destination controlled by a switch.
I really don't understand what you are trying to do. Would need a more detailed description.

I really don't understand what you are trying to do. Would need a more detailed description.

Speciffically what I am trying to do is take one of those "performance chips" that are all over ebay, which are just a resistor in a box, and wire it into a switched on/off type of circuit. Then I am going to put it on a dyno. They splice into an intake sensor and trick the ECU into dumping more fuel into the motor. I want to split the wire, that these are intended to be spliced into, into two wires controlled by relays, with the resistor on one of them. They would then run back into the same wire going to the ECU.

I was thinking that the switch could turn one circuit on and the other off via relays. Directing the signal through the desired path like a railroad track.

I have never did anything like that but yes, you can do that. Would this all be controlled by a switch? Relays can turn on or off circuits, relays can control other relays ect..

sounds like you are trying to do it the hard way. all you need is spst on/off toggle.
________/\/\/\_____/ _____
from sensor / resistor switch \
----------< >----- to ecu
\________________________/


well.... that looked a whole lot better when i typed it up. heres a crappy schematic. i have to get back to work now. one comment about what i did, check resistance of the switch as not to provide too much resistance combining the resistor with the switch.


http://www.chevelles.com/showroom/showphoto.php?photo=7281&cat=500

all you need is spst on/off toggle.

How would the normal circuit from the sensor to the ECU be completed with the toggle off?

Relays can turn on or off circuits

What type(s) of relay(s) do I need to do this? Would I need two relays?

How would the normal circuit from the sensor to the ECU be completed with the toggle off?
You would need a SPDT 5 terminal relay, which also has a 87a terminal. power can flow from 30 to 87a when the relay is switched off. When the relay is switch on, power is cut to 87a and applied to 87. If this does not help, post or email a schmatic of what you are trying to do.

Greg, I sent a drawing to your AOL email.

The signal from the sensor branches off into two. The relay(s) only allow one circuit to complete. Therefore, the ECU either sees a modified or unaltered signal based on the position of the switch controlling the relays.

How would the normal circuit from the sensor to the ECU be completed with the toggle off?

Good call. I was thinking it would not matter, but with the resistor in parallel with the normal circuit from the sensor the electricity would take the path of least resistance and bypass the resistor anyway.

Sounds like undee70ss has it down.

seems like what needs to happen is

sensor -> 30
87a -> ecu
87 -> resistor -> ecu
power -> switch -> 86
85 -> ground


switch should be spst toggle (on/off) or a momentary switch based on your preference, though i doubt you want to use the momentry and have to hold the button while you are testing how the engine runs with the resistor in place.

Greg, I sent a drawing to your AOL email.
I never did recieve it. My email address listed here is correct.

Greg, I sent you the image again. Its coming from the email address aengli01@shepherd.edu

Joe, the way said the relay should be used makes sence. Will that work if the signal from the sensor is a negative (-) ground signal?

I think I could also get the results I want if I had a toggle switch with two inputs and one output so I could switch between the two signals. That would eliminate the need for relays, but would require running the wire from the sensor all the way into the cockpit.

(-) or (+) should not matter... the relay merely opens or closes a circuit.



true, too about having the wires coming through the cockpit, but the toggle will have 3 wires, the switch and relay will still have 2.

How would the normal circuit from the sensor to the ECU be completed with the toggle off?

You put the resistors in series and the toggle switch in parallel with the new resistor. If the switch is closed, the new resistor is shorted out of the circuit, if the switch is open, the resistor is in the circuit.

You put the resistors in series and the toggle switch in parallel with the new resistor.

Could you possibly post or email a schmatic of exactly what you mean.

aengli01@shepherd.edu

Thanks!

I don't draw well...

-------old resistor/sensor---------new resistor-----
_____/\/\/\/\/\_________________/\/\/\/\/\/\/\_____
Put the switch in parallel here │_____/__________│

With or without a resistor, how would the resistance added to the circuit vary between the relay option and the non-relay toggle switch option?

Speciffically what I am trying to do is take one of those "performance chips" that are all over ebay, which are just a resistor in a box, and wire it into a switched on/off type of circuit. Then I am going to put it on a dyno. They splice into an intake sensor and trick the ECU into dumping more fuel into the motor. I want to split the wire, that these are intended to be spliced into, into two wires controlled by relays, with the resistor on one of them. They would then run back into the same wire going to the ECU.

I was thinking that the switch could turn one circuit on and the other off via relays. Directing the signal through the desired path like a railroad track.

A resistor has just two leads, and it can only be installed one of two ways, series or parallel. Does this "performance chip" install in series or in parallel with the existing sensor?

Greg, I sent you the image again. Its coming from the email address aengli01@shepherd.edu
Got it, I would wire like this.
30 to sensor
87 to resistor, then to ECU
87a to ECU
86 to IGN power
85 to a toggle switch, then to ground

Whenever switch is on, new resistor will be in the circuit, when it is off, normal operation.

Joe, the way said the relay should be used makes sence. Will that work if the signal from the sensor is a negative (-) ground signal?Joe is correct, a relay is nothing more than a switch, doesn't make any difference if is pos or neg.

I think I could also get the results I want if I had a toggle switch with two inputs and one output so I could switch between the two signals. That would eliminate the need for relays, but would require running the wire from the sensor all the way into the cockpit.
A switch like this would work
http://www.chevelles.com/showroom/data/500/toggle_switch_pics_001.jpg
This is a on/off/on toggle. If you use just a switch, make sure to check it with a ohm meter, some buss all 3 terminals (mostly found in a slide type switch) others do not. This switch, the center terminal is common, only bussed to one of the 2 outer terminals in any on position.

I'll be curious to see how this works for you, and how much resistance you use. a friend of mine asked me if he should get the same thing from ebay for $20 or so. i told him no way, not for a 10 cent or whatever part from radio shack.

Keep us posted.
-Joe

A resistor has just two leads, and it can only be installed one of two ways, series or parallel. Does this "performance chip" install in series or in parallel with the existing sensor?

The signal to the ECU runs through the resistor. In one lead and out the other. Series, I guess is what that would be.

a 10 cent or whatever part from radio shack.

Are these resistors something I can buy at Radioshack? Does anyone know an online source other than the ebay scammers? I've seen two types of "chips" available on ebay. One is a very small, thin resistor on a solid wire that bridges the socket for the sensor, therefore taking the sensors place.

See:

http://cgi.ebay.com/ebaymotors/20HP-POWER-PERFORMANCE-CHIP-NISSAN-240SX-240-SX_W0QQcmdZViewItemQQcategoryZ33597QQihZ002QQitemZ 120013475687QQrdZ1

The other is a larger (meaning physical size, not measure of resistance which varies between models) type of resistor in a box with two leads into and out of it.

See:

http://cgi.ebay.com/ebaymotors/Ford-Mustang-Ranger-Explorer-Performance-Chip-99-98-97_W0QQcmdZViewItemQQcategoryZ107070QQihZ009QQitem Z190014956528QQrdZ1

That sellers listings actuall had fake OEM part numbers on the resistors themselves. You could tell he did this with PhotoShop or simalar program.

http://i19.ebayimg.com/04/i/07/cf/d5/d6_2.JPG

The IAT sensor is a resistor with a negative temperature coefficient, as the temperature goes up, the resistance goes down. If you install a fixed resistance as shown in the picture, you can fool the computer into thinking the air is colder than it really is. If you install a fixed resistance in series with it, it will fool the computer the same way. The 9T51 chip shown in the other auction probably has a resistor between the two pins used.

Try adding values between about 2k ohms to 5k ohms of resistance to the sensor resistance and see what happens. The problem is that the IAC does not produce a linear resistance curve as the temperature changes so I can't just say something like 2k = 20 degrees C and be correct.

-20C = 25000 ohms
-10C = 13500
000C = 7500
020C = 3400
040C = 1800

This should give you some idea of what to do.

Peter

I got resistors from radio shack. Packs of five for $0.99. A lot better than 30 bucks each from a con artist on ebay. They range from 1K ohms to 10K ohms. I tried just jamming one of the 10k resistors in the sensor socket like the one ebay photo showed. There was no noticeable difference in performance. I left the socket unplugged with the resistor removed to see if the computer returns any codes. I am not sure which wire is to and which wire is from the ECU. Does this matter when I do the hard wiring, or do I just need to get the resistor somewhere in the circuit? Are there any other sensors that can be manipulated in such a fashion to alter the fuel/timing curve?

No, spend the money and buy the equipment to program the computer. Then, you will get to really program it and not just add some poor excuse for a performance modification.

Try upping the fuel pressure a bit more if you want more fuel. The fuel is basically injector one time x injector flow rate/psi x fuel pressure. So, add pressure and you get more fuel.

Peter

So do you know where I can get such magical programing hardware? I wasnt aware of such things except for popular applications such as domestic trucks. Nothing in the world could make me happier than a universal OBDII programer. Other units, like Venom modules (common "mod" for hondas and dodge neons and such), are just elaborate piggyback systems (like I am trying to make without spending hundreds of dollars).

Are fuel pumps/pressure regulators wired to the ECU in such a way that they could be subject to signal manipulation?

What about timing?

MAF sensor?

After removing the resistor from my inital test, I left the socket unhooked to see what happened. Check engine light came on, codes read PO113 - IAT sensor input high. No codes were returned when the resistor was in the circuit. Do both the sensor and the resistor add resistance to the circuit when they are wired in series?

I found a product that claims its a "computerized interphasing module that recalculates the pulse width command from the vehicle’s computer and relays the reformulated pulse width to the injectors". It is advertised as a universal application. Is this B.S.?

Got it, I would wire like this.
30 to sensor
87 to resistor, then to ECU
87a to ECU
86 to IGN power
85 to a toggle switch, then to ground


It works the same way if 85 goes directly to ground and 86 goes to IGN power through a toggle switch, right?

And when that circut is completed, is it 87 that is open or 87a?

It works the same way if 85 goes directly to ground and 86 goes to IGN power through a toggle switch, right?
Yes, you can do that too. It is the same thing
And when that circut is completed, is it 87 that is open or 87a?
When applying power to 86 and grounded through 85, power flows through 30 and 87. 87a is open.

When power is removed from 86, or 85 looses its ground, power flows through 30 and 87a. 87 is open

by "open" you mean no signal flowing through it, correct?

can I wire it like this:

------------------------\_____________________> final signal to ECU
_____________________/

with 87a and 87 running together with resistance on one of the wires before they meet. Let the dotted section represent where the resistor is. Will that work so the final signal to the ECU only sees resistance based on the relay?

by "open" you mean no signal flowing through it, correct?

can I wire it like this:

------------------------\_____________________> final signal to ECU
_____________________/
Correct, open means no signal.
with 87a and 87 running together with resistance on one of the wires before they meet. Let the dotted section represent where the resistor is. Will that work so the final signal to the ECU only sees resistance based on the relay?
Correct. i would have 87a for normal operation, and 87 for the resister so the resister is in the circuit only when the relay is on.