enrichment curcuit voltage 250 yamaha

[gofastjoe]

I am trying to find a cold no start prob on my 91 250 TXRP, the enrichment pump is working, i checked voltage on the red and purple wire that go to the valve/selenoid on each carb and each wire has 12 volts, key off, key on, and cracking. I cant find a spec in the manual for this, i have had trouble with the harness before and suspect i have another. Any help would be great.

[rodbolt17]

should have 12V to each solinoid, the ECU supplies the ground path to operate the solinoids when needed.
they operate at cold start,a function of the coolent temp sensor, they operate at rapid acceleration/decelleration a function of the TPS and they operate at knock detect a function of the knock sensor.

[gofastjoe]

enrichment

so voltage only on one wire not both, sounds like a harness prob, again.... Thanks

[rodbolt17]

six wires have 12V to ground at all times, the other six wires go to the ECU where the ECU supplies the ground path for injector(solinoid) operation.
no ground path means no current flow which means no solinoid actuation.
check the harness from the ground path side to the pins on the ECU conector.

[gofastjoe]

So i schould not have 12 volts on both the red and purple wire, on each selenoid. Thanks

[rodbolt17]

draw a simple circuit.
battery positive to the solinoid then from the solinoid to the negative battery terminal.
this will be an operational circuit.
now place a switch in the path between the solinoid and the negative battery terminal.
open the switch.
now the circuit is at rest.
now place one meter lead on the negative, now place the other lead on the battery,should show battery voltage,now move the positive lead to the first connection point of the device. should stil show 12v,now move it to the other side o the device,should show 12v, now move it to the device side of the open switch,should still show 12v.
you MUST understand basic 12V circuits and the difference between Voltage and current(amps).
voltage is simply a measure of electrical pressure(potential) between 2 points in a given circuit.

[gofastjoe]

Thanks for the help, bad spot in the wiring harnes on the ground side for the selinoids. started right up. now if it wasnt blowing 25 NE i could fish.