googled the part number you provided and one of the hits was
on mouser website:
https://www.electro-tech-online.com/custompdfs/2003/12/869.pdf
It also includes pinouts which is "D4" for this series with terminals
"1" and "16" being positive and negative. Coil resistance is listed as well.
Your part number is not complete, it's missing DC5, DC12 or DC24
on the end (Omron standard). Make sure you are using right voltage
(+/-20% is just fine). To verify if the relay toggles check if you
are using proper contacts (4 and 8 is first NO contact).
In case coil resistance is ok and your power and polarity are ok,
maybe the contacts got welded. What is load you are trying to drive
with this relay? (voltage, current, AC/DC, inductive...?)
How are trying to drive it? (transistor?)
Do you have supperssor diode accross coil?