M915 No Turn Signals

[flametamer]

I am having a problem troubleshooting the turn signals on our fire depts. M915. I have looked at the TMs but I do not understand them. It had an intermittent problem with the left turn signal, no neither side works. The light on the turn signal switch flashes but that is it. I know when they were working, you could hear the relays clicking, now nothing.
I don't seem to understand the flasher either. The purple wire it the input, the blue wire is the load and the yellow it what? When the flasher is off the yellow wire reads 12volts just like the input. When I turn either turn signal on, the yellow goes dead and +12 alternates on the blue. Is this correct?


Dt

 

[NDT]

Mine does this occasionally. For my truck, I have to wiggle and reseat the Molex connector from the turn signal control that is under the steering column.

 

[R Racing]

I had to replace the flasher on mine it's under the dash and a bit to the left. Theread ate also relays that could go bad they control both the 12v lights and 24v if I remember right. There under a panel on the right side of the cab with the twist lock screws. Your problem may be there.

 

[flametamer]

I replaced the turn signal switch, it is the same model but the wire colors are different. I pulled the covers of the new and old switch and matched wire locations so I'm sure it is wired right. I spliced the wires into the old harness before the Molex connector. I might bypass the connector to see if that is the problem. Where can I find a replacement flasher? I've had no luck locally. Dt

 

[Artisan]

...and your making sure the blackout switch is in proper position yes?

 

[Old Lincoln County Iron]

I found some flashers at fleetpride. I bought new ones when I switched to led bulbs. Think they were 16-18 dollars.

 

[flametamer]

...and your making sure the blackout switch is in proper position yes?

Yes.

 

[Artisan]

I think your part number is A-105A-5

NSN= 5945-00-132-6422

 

[flametamer]

I found the problem. The power in terminal on the flasher (X?) either has a cold solder joint or there is some corrosion in the contacts. Hold the terminal one way & everything works, let go, and nothing. Is the Truck-Lite 263 a compatible flasher for these trucks?

Dt

 

[Castle Bravo]

This is what the -24P TMs say -

M915 Crane Carrier Company A-105A-5
M915A1 Herley Chicago 15513

It is my experience that flashers with the correct voltage and number of connectors will work.