Tyco (aka TE Connectivity) part number T72M5D155-12-12, also known by alias numbers 3-1393289-1 and T72M5D155-12-12=T72, is an obsolete relay that seems to be difficult for a lot of people to replace or cross-reference.
TE doesn’t list the complete specifications on their site anymore, but if you are willing to visit third party sites there is an old datasheet uploaded here: T72MD155-12 Datasheet
I’ve had quite a time trying to cross reference this and I finally think I have a good replacement option, if not a direct cross-reference item in 2449-J107F1CS2012VDC.45-ND from CIT Relay and Switch, see below for basic information on this. I confirmed that it matches the original footprint of the TE relay, as well as the pinout, though it is not classed as an automotive relay. This may be of concern if you are using this in a motor vehicle, but it is frankly the only viable option I’ve seen so far.
| MFR PART # | J107F1CS2012VDC.45 |
|---|---|
| DIGIKEY PART # | 2449-J107F1CS2012VDC.45-ND |
| MANUFACTURER | CIT Relay and Switch |
| DESCRIPTION | General Purpose Relay SPDT (1 Form C) 12VDC Coil Through Hole |
| DATASHEET | Click Here |