chub406

Im wiring up the ethanol sensor on my holley. Says I need a 10k ohm resistor. I couldnt find examples people are using. Went to a radio store and asked for one. He asked me what wattage I needed. I had no idea and just said its for a 5v signal. He sold me one and it says 5w on it. Is that the right one? I haven't been able to find any that guys are using and to be honest. Dont know if the wattage size makes a difference here. lol

3 window

iTrader: (1)

Not sure the wattage matters. Mine has four color rings on it (brown, black, orange and gold) and it works fine.

svslow

According to the Holley manual "Any 10k Ohm
resistor can be used."

roastin240

iTrader: (13)

Well....lets figure it out quick....

Voltage = Current * Resistance
12 Volts = Current * 10,000 ohms
Current = 0.0012 amps

Lets see what kind of current your 5W resistor can handle:

Power (watts) = Voltage * Current
5W = 12V * Current
Max Current allowed for 5W resistor= 0.4166 Amps

You could have used a tiny 1/4 watt resistor, or even a 1/8 watt resistor.

Minimum wattage of resistor would be:

P=V*I
Power = 12 Volts *0.0012 Amps
Required Power = 0.0144 Watts

Don't confuse wattage with resistance. However, your doing no harm with a higher than required power rating, so you will be fine with what you have. But the lower wattage are the physically smaller resistors and easier to hide in the harness.

Nathaninwa

^ perfect response

Project GatTagO

iTrader: (7)

denmah

iTrader: (2)

i am not using one at all and i dont have any problems

/habitual line pusher

3 window

iTrader: (1)

I've seen/talked to people and some have used resistors and some have not with success. The only thing I noticed that's different is the people that don't use the resistor use the large body continental sensor (the square body style with the mountig holes). The ones that needed a resistor are the people using narrower body sensor (rectangular shape and no mounting holes). Makes me think maybe the square body sensors already have a resistor inside it. Idk, maybe I'm wrong but that appears to be the case.

chub406

Dam you, Denmah! Always doing what you aren't suppose to! lol I was literally walking out to the garage to wire it up and then you throw this crap at me! haha What sensor did you use? I watched your vid of you going and putting in just the e85 and the results. The only other way to test it would be to put pump gas in it and see what it says, wouldn't it? I don't remember if you had already done that too. I know the winter blends are suppose to be lower % to help starting. I wonder if that was why yours had the lower % or if not having the resistor makes a difference in the reading? I read the 5v and resistor just amplifies the signal to the ecu.

The one in the instructions is the wide sensor with the mounting holes. That says use the 10k ohm resistor. Thats the one I got.

forcd ind

iTrader: (7)

I got a pack of 4 from Radio Shack, used the GM sensor listed in the Holley
instructions-with 93 octane from a pump that says contains 10% eth, I read
8%-so I made that 0% fuel added, then dumped 5 gallons of E85 (tested from the pump and was E85) it rose to 24%.
I noticed a smoother idle, was kind of surprised by that.