Engine Fire Warning B737
 

Short question to the B737 experts :
you do your engine fire warning test and the Fault/Inop-test does not illuminate the FAULT light. Can you go or are you AOG?

I think your AOG if the FAULT light does not iluminate on test AND you have a loop inop. But Ill check the MEL and get back to you.

As far as I can remember, if you don't get the fault light (both loops selected), switch to loop A, if the fault light now comes on (not while testing), a loop A fire wire on the applicable engine is inop. Now try the test on loop B, as long as the test is satisfactory on the remaining loop, the aircraft can be dispatched albeit with restrictions as per MEL.
I think that is so anyway! Hope it helps.

For the Fire and Overheat System Test, with the OVHT DET switches in NORMAL:

Place the TEST switch to FAULT/INOP

If the Master Caution lights, OVHT/DET annunciator, FAULT light and APU DET INOP light illuminate, the Fault and APU Detector Inop circuits are normal.

If the FAULT light fails to illuminate, the fault monitoring system is inoperative.

In this case I think you are AOG - I would have to check the MEL to be sure, and I don't have access to one at the moment :(

When you place the TEST switch to OVHT/FIRE, it is the illumination of the Fault light that tells you you have a problem in one of the loops. You then have to go throught the procedure to determine which loop that is, disable that loop and continue under the MEL for one loop inop.

Except for ER Ops beyond 120 mins, 1 loop (A or B) per engine may be inoperative.