79’ KZ Oil Pressure Sensor: Just the wire?

Howdy all,
New owner of a fully running, nearly bone stock 79 Kz400B. Previous owner snagged it from a barn zipped around on it enough for 20
odd years to keep it running pretty well. I’m just putting it through some paces before I start deep cleans/rebuilds and have a leak at the oil pressure sensor.
The wire is cracked and it looks like oil is running from the crack down, but it’s hard to tell. Otherwise the sensors seems to be acting normally (ie send no pressure signal with engine off and key on). Any chance the leak is just from wire or should I just go ahead and replace the sensor too? Looks like there are a few options out there on eBay, but definitely down for recommendations. I’m kinda new to this stuff so apologies in advance if I said something dumb. Thx, looking forward to being part of the community.
-Tim
 

Oil can only leak through the switch not the wire, it will however over time capillary up the cable and contaminate it (Mercedes cam sensors capillary oil all the way to the engine ECU  )

wrote:

Oil can only leak through the switch not the wire, it will however over time capillary up the cable and contaminate it (Mercedes cam sensors capillary oil all the way to the engine ECU 

)
 

I was going to mention the exact same example - cam sensor connectors start to leak and press the oil all the way to the ECU, where the oil insulates the connections and starts wreaking havoc. You can clean it all, but once the oil is in the harness it will keep causing problems until the sensor and harness are replaced.

For this case I'd replace the sensor, I agree that's the likely problem. The wire is just a wire, nothing special, but if a replacement can be found that would be good, the boot looks pretty poor (you may be able to just change the boot). Once they've had a lot of oil the rubber boot can break down.

 

Thanks Wookie and Yobbo. I found both the wire and sensor on eBay in seemingly good condition so I’ll replace both.
This happened after the bike’s first oil change since I bought it. The old oil didn’t look too gnarly and quantity was fine. So I’m slightly confused by what would have caused the leak. I was careful not to overfill. Could fresh, slick new, oil plus increased use as I feel out the bike cause the sensor to blow? Maybe a change in pressure despite my keeping a close eye on oil quantity? 
thanks again, it a pleasure to be in the community!
-Tim

Most likely caused by old age, and unrelated to new oil, et cetera.

I agree with Texas, you haven't done anything that could cause the sensor to break, it's just age. Even if changing the oil did break it, anything that's going to break by giving it a service is due for replacement anyway.

Thanks Texas and Yobbo. That was my thinking as well. I’ve been riding the bike a lot more than the last owner too. So I’m expecting some stuff to give up the ghost as I tune it up for more regular use. He took good care of the bike but only rode occasionally. 

Just for posterity— I found a lightly used oil pressure sensor from a 78 KZ400 and replaced it. Per above recommendations that fixed the issue.