O/D Off flickering. 2000 Mazda B3000 manual trans.

[Ramsey4]

Hey guys,
As the title says I have a 2000 Mazda B3000 flex fuel with a 5 speed trans. The "O/D off" light is flickering in every gear including neutral. Shifting is normal and I replaced the trans fluid after it started lighting up but was not low or overly dirty. Truck has 142xxx miles and I don't think it was converted over from automatic. Any ideas? I figured only autos would have an "OD off" light.
Thanks

 

[RonD]

Welcome to the forum

All instrument clusters have the same lights, so manual trans would have OD light just not used, but it is wired

Most likely an issue with the wire from cluster to computer
In below diagram, left side toward bottom you will see Transmission Control IND, thats the OD light
That light bulb gets 12volts with key on, its other wire is GROUNDED by the computer(PCM) as needed, using Pin1 wire(white/light green stripe) on connector 214(C214)

So either PCM is doing it or white/light green wire is shorting to ground in the harness

Pin 79 at the PCM connector in the engine bay could have some corrosion, next pin over is pin 80 the fuel pump relay ground

 

[Ramsey4]

Thanks for the welcome and all of the info. I'll check when the snow dies down. I'm going to assume it's a wiring issue since I did unhook the battery the other day for a half hour and that didn't reset the light. Doesn't seem to affect anything mechanically, other than being annoying, so does it matter if I just pull the bulb if I can't figure out why it's flickering?

 

[RonD]

Yes, you can just pull the bulb

If you pull the cluster also replace the 6 back light bubs, just as general service

You could also pull the pin 1 white/green wire out and then plug cluster back in and start vehicle to see if OD light stopped flickering, if so its a wire/PCM issue, if it still flickers then its a cluster issue, pull bulb

 

[cbxer55]

I've been having the same issue with my 07 4.0 Mustang with the 5R55. But it only flickers in OD at in town speeds. Get it on the highway at 60 or better, never happens. It's a P0741 on mine, Torque Converter Clutch Locked Off. Been throwing money at it trying to fix it. Yesterday, my friend who has a transmission shop told me it is highly likely to be a bad TPS. Since around town, it's kind of herky-jerky before the light flickers. Like it's trying to make up it's mind if it should lock or not.

 

[Dirtman]

Manual transmissions usually don't have torque converters...

 

[Ramsey4]

Thanks RonD. Good call on the illumination bulbs, 2 or 3 are burnt out anyway.