92'longbed4WD

This is my first post (Hello, Everyone!) and I was hoping I could get some !Help! with a problem I encountered swapping in an SR5 cluster into my 92' pickup. I have a 6cyl. 5spd. 4WD with electronic speedo. Swapping the cluster was no problem and everything works except the oil pressure guage. When I swapped the oil sender from a idiot light to a pressure sender type my oil pressure gauge reads nothing at all?? I did try and swap the idiot light sender back in just to see if the guage would work and it did peg the pressure needle when the switch is turned on. I did not leave it on as I have heard that it could/would damage the cluster. The pressure sender is a brand new from my local Toyota dealer, so I don't think the sender is bad?? I was wondering if both senders do use the same connection wire to feed the cluster?? because there is also an extra wire that is next to my sender wire that I have no idea what it goes to?? It appears to have a side by side type connector. Any !Help! with this would be greatly appreciated

Thanks,
Scooter

Mack

Here is an FAQ on the cluster swap which may help