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Discussion Starter #1
Last week I posted about a issue where when I put it in reverse my rpms would fluctuate like it wants to stall.
Yesterday when I went to warm her up the batteries were flat dead. Charged them and off I went to work. Coming home my o/d light on shift lever starts flashing. Great, now what...This morning I went out and was going to warm her up and run a test with my new A/E tester. Batteries dead again. OK, charger back on. Left it like this while I cleared the driveway of fresh snow. When I shut the blower off I could here something running in truck. Look in, key not in switch but my fan motor was running. Ah Ha. Must be the relay sticking. Its under the hood. But the sound was coming from under the radio area. Now my fan switch has only worked on high for awhile if that makes a difference.
I am still not overly knowledgeable on how to use this new tester, I was able to retrieve codes but did not know how to store them so I took a picture. The blower issue I have ordered a new blower resistor and a relay, but the flashing o/d light has me not wanting to drive it. Does this picture show anything of concern? What could be clicking in the underdash radio area.

I have poured my sole and savings into this for the last few years , having just don
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e new body and paint and having a 3/4 rebuilt engine sitting in my garage waiting for spare change to finish. Its my only vehicle now and any help would be greatly appreciated
 

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Discussion Starter #2
Took dash apart, the clicking with key out/off is coming from the three? flasher units just to the right of the steering column
 

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Discussion Starter #3
Just went for a short drive. The light stays off for a few blocks, shifts fine. My speedometer is erratic though. Jerky and bouncy.
 

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Can you remove the three flasher units one by one and see if the noise stops?

Thats tough on the batteries to drain them down especially in winter cold temps. A real concern you could be left stranded.
 

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Discussion Starter #5
I can remove, I have the dash apart and can reach in and feel them. Forgot to pay attention to which one it was. Will follow through in the morning. I'll try just replacing it with a new one. Its the over drive light that has me worried. Hopefully our resident transmission expert comes along
 

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Does it still blink when the DP Tuner is set to stock mode?

The only Powertrain Code (P) that you pulled up which causes the O/D to flash is the P0500 Variable Speed Sensor, right?
 

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Discussion Starter #7
Yes it blinks in stock mode, tried turning o/d off and going for a ride and same thing. About a couple of blocks till it flashes. I dont understand the codes, I thought since they all had a check they passed?
 

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When my truck acted up like this it was because the fuse block got wet from the windshield leak. Internal to the fuse block water was shorting the traces, letting power get to where it shouldn't. Batteries were almost dead after sitting overnight, the blower was on, and the radio stuck on.
 

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VSS is Vehicle Speed Sensor, not Variable Speed Sensor.

Yes it blinks in stock mode, tried turning o/d off and going for a ride and same thing. About a couple of blocks till it flashes. I dont understand the codes, I thought since they all had a check they passed?
It shows these codes because those are the faults that the PCM has detected.

Because you have a P0500 and an erratic speedo you probably have a failing Vehicle Speed Sensor. It's located on top of the rear differential. This sensor is magnetic, so you might just have some metal filings on the end of the sensor that is inside the differential.
 

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Discussion Starter #10
Is the VSS something I should get from the dealer or is a jobber one ok?
 

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Thanks Mark,

I fat-fingered it somehow.
 

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I would go with a Ford one but you can try one from the auto parts stores.
 

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Discussion Starter #13
Thought I would save time and just do it in the driveway, darn thing broke. Time to thaw it out and put it on the hoist. Might as well do the pinion seal and fluid change at the same time. Thanks for the help so far. I will post the results
 

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Discussion Starter #14
I was able to use a screw driver and pry the broken piece out. Not sure what debris could of fallen into pumpkin so I might as well do a fluid change now as well. Dont know if its overkill or a bad idea but I am using the oil pan silicone from ford to seal the diff cover. I'll let it sit 24 hours and then fill it. Likely know Monday if it helped with the issues
 

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Discussion Starter #15
So it sat the 24 hours. I used the royal purple synthetic 75/140. Buttoned her up and off we went. No more flashing o/d light. Thanks for the help.
 
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