cwsttu

hey im testing all the input wires that go into my ecu for resistance just to make sure that there is not going to be any electrical probs when i hook my new one up... checking all of the power input wires the only ones that show resistance is

1I - which is the 5th switch that should be approx 12volts when in 5th gear and 1.5 in all other gears... testing this out i find resistance in every gear BUT 5th... this is so my car knows im in 5th gear to let the cruise kick on i assume.. what im asking is there supposed to be resistance in gears 1-4 and reverse.. if so that tests out fine

the other question i have is....

3B - i found resistance on this wire which goes to the starter switch and it should be below 1.5v or approx 12v on crank.. is there supposed to be resistance on this wire?

thats my main concern as of now.. like i said i do not want to toast this next ecu even though i think the AFM was my only problem which gave me HUGE resistance on the brown and white wire in 2A

thanks guys

christopher

cwsttu

bump anyone?

cwsttu

ok update... on the following resistance is shown for 3B

off = 22.5
on = 58.6
crank = jumps from 48.5 to 58.6

anybody know if this is normal.... that is a power wire why would it have so much resistance.. is it the way the starters are on our cars?

J-Rat

iTrader: (2)

Lets attack the 5th gear switch first.

If it has resistance in every gear but fifth, then its probably inducing a ground to a 12 V potential.

what does that mean? that means that you can apply 12 v to the switch. But without a ground, you will still have no reading.

As for the starter circut, I have no idea what normal Ohmic values would be.

Jarrett

cwsttu

anybody else..... i would like to hook this ecu up tomm but i would like some feedback about the starter wire... thanks j-rat what you said makes sense...

Icemark

You are not testing these wires with the ECU plugged in.. right?

Either way, 3B is an output wire, and it feeds voltage out. If you were metering it between ground and the wire, you would see the resistance of the coil on the relay.

On 5th gear switch, on Turbos and 88 verts you would see the resistance of the split air solenoid.

cwsttu

no im not im just checking for resistance so that when i plug the new one in nothing bad goes thru it... the reason i started doing this was because my ecu was fried and i needed to find the problem... i did and it was the AFM but now im just doing all the input wires just to make sure that everything is in good condition

Icemark

what was burnt on the ECU before??? It should be very simple to check what caused it if you know what was burnt.

cwsttu

im sorry icemark when i said fried i did not mean anything obvious in the ecu... i shorted something out a while back dealing with my AFM... does the AFM have anything to do with the starting wires going into the ecu? what i meant earlier was i grounded a wrong wire at the AFM and that made the ecu just go bad and put out only .23 volts on the brown and white wire going to all 5 sensors in the engine bay

Icemark

yeah, shorting that would blow one of the power supplies in the ECU.

And no, neither wire you mention would have any effect with the AFM or reading of the AFM by the ECU. In absolute worst case the if you shorted 3B directly to ground you would only waste the protective resistor for that wire in the ECU.

If the 5th gear switch (or "over the top switch" if you want to be accurate) was shorted, to ground, nothing would happen to the ECU, however you could burn up the switch itself. Of course shorted to 12v+, and the ECU would just think the car was in 5th and switch the split air solenoid on.