VRO 2 pump wiring

I am installing a new VRO2 pump into my 1989 Evinrude 175HP outboard (E175TXCEB) the new kit has the 4 prong plug so i need to convert my current 3 wire setup to the 4. the wires coming from the pump are black, tan, grey and the new wire purple. the wires on the engine side that were orginally connected to the 3 wire plug setup are supposed to be black, grey, and tan. this is not the case on my engine, they are black, grey, and grey (prior ownder must have messed with the wires). i did not mark which grey wire connected to the tan on the pump side when i disconnected the old pump. is there a way for me to test which of the grey wires is supposed to be tan so that i do not connect the wrong wires?

i know black goes to black and the purple is going to run to the purple terminal strip on the engine.

any help is grateful
thanks in advance

Re: VRO 2 pump wiring

The grey wire that is SUPPOSED to be grey is the tach signal. You can use an ohmmeter set on continuity to probe the two grey wires at your pump using one meter lead, and put the other meter lead on the known grey tach lead. When you get continuity...you have found the proper grey tach lead. The other wire will be the SUPPOSED TO BE tan. Of course power off for this testing.

To be on the safe side, you should put a long wire on the grey tach lead up at the helm, right on the tach, and extend it back to the engine. The grey wire pin and the tan wire pin are side by side in the center of the big red plug, so you could probe on the wrong pin of the big red cannon plug if you tried it there.

Re: VRO 2 pump wiring

The grey wire for the Tach should run directly to the voltage regulator. Trace it out and see where it goes. It sounds like a pretty easy fix, if you can get the 4 wire connnector and some conector pins.

Re: VRO 2 pump wiring

the wires on this engine are a disaster because of the previous owner; they are not color coded properly, spliced, bundled together and wrapped with electrical tape and a mess throughout the engine so it will be very difficult to trace the wires to the regulator.

someone told me if i ground the "tan" wire the warning siren should sound, does this sound correct?

thanks for the help

Re: VRO 2 pump wiring

Dunno. Very hard to say. It is not wired right.
On a correctly wired engine, with everything connected, grounding any of the tan sensor wires will cause the horn to sound.
But yours is not wired right. Who knows if the sensor circuit even works?
Does the tach work? If so, you absolutely know that the grey wire tach circuit has one end up at the tach, and you can easily get to that point. That's why I suggested probing one end up at the tach itself, and using a wire to extend back to the engine.

You could try it, engine off, key on.....if the grey wire that is really supposed to be tan is wired right, the horn will sound if you ground it. If you ground the grey wire that is correct grey (the tach circuit)....nothing will happen. Don't ground any wires with the engine running. You may blow your tach circuit from the reg/rect.
Just to let you know....I have no idea if grounding the tach circuit with key on and engine not running will damage anything. So be warned. You have a 50/50 chance here....I do know that when you turn the key on, the tach "zeros out", so there may be SOMETHING on that grey wire when powered up. I never had to measure anything like this before.

I am trying to suggest ways to ID this wire with very little to no possibility of blowing/burning up something.

If it were me, I would start the engine, and measure the voltage to ground on both wires. The grey wire that is the tach signal will have an AC voltage on it, and MAY require the DVA adapter to get any measurement at all. I have no idea what the voltage would be, but it doesn't matter. I would just be looking for voltage. The grey wire that is really supposed to be tan will have no voltage at all on it, again, IF WIRED RIGHT.
You could ID it that way.

The safest method is to use the continuity function of your meter, probing both ends until you absolutely ID the proper wire. Can't do any damage this way.