Reverse light fuse blows when shifted into drive

[Jason Leadbetter]

I will try to make this short...2001 Sport Trac



Before I get started...I have had the flashing OD light from hell and fixed it...Cottman Transmission...$1900!!!

Now on with the show...For at least a year now I have had no reverse lights and the ST will not allow me to override OVERDRIVE with the switch on the shifter. The fuse that controls the reverse lights and the OD override (I guess) is #20. Now if I replace it with a good fuse and put the ST in DRIVE, the fuse blows. The ignition can be in the ON position...without starting the engine...or it can be running...doesn't matter!!! Has anybody tackled this issue before? The truck is completely stock. I have read about the steering column issue and don't believe it to be the issue. I am almost at my wits end...



Thanks,



Jason

 

[Kevin Palmer]

First, did the fuse issue exist prior to the flashing OD light?

Did it exist after the flashing OD light?

Did it exist prior to, after, or before and after the service of your transmission?



Both the PRNDL (Park, Reverse, Neutral, Drive, Low) switch and the tranny itself have wire harness that deal with the reverse light operation. Pretty sure the OD button is only affected by the Tranny and where ever the power feed as well as the ground feed are.



Answer the questions above and we will be able to isolate this better for you..

 

[Tom Higbee]

States for over a year no reverse lights. Pre existing...sounds like to me.....either the line running to the reverse lights is grounding out or the switch is grounding out....that's where I would start. I would isolate the line....disconnect from reverse light swich and replace fuse...if it doesn't blow, then it from the reverse lights to switch...if it blows, it's the switch. A place to start for now!

 

[Bill Ellis]

Obviously there is a short cricuit somewhere in the system. Try this in an attempt to isolate it. Disconnect the tailight assemblies. Put in a new fuse and see if it still blows. If it doesn't then the short is in one of the tailight assemblies. If that is the case, reconnect one at a time and retest.

 

[Kevin Palmer]

trtex, I agree he did state that. But he does not make it clear how long the light had/has flashed or when the tranny was serviced based on the issue at hand...

 

[Richard L]

If you have had any transmission work done , you may need to take it back and have them check the wiring. Itt has been reported that if the internal wiring harness gets pinched it causes the backup fuse to blow and you get a flashing O/D light.



If you have not had any work done, then you may have a cracked or damaged wire that is grounding against the transmission case, with the same results. Probably from hitting some minor road debris or off-roading.



...Rich

 

[EddieS'04]

I would look into what Rich L said...a friend had his chevy van trans worked on..they screwed up his wiring harness..it got against the exhaust and burned up....but he started having some of the same problems before it burned intwo...

 

[Jason Leadbetter]

Thanks for the suggestions...FYI...the reverse lights stopped working well before the FODLFH problem started. I hope to get a nice weekend soon to resolve this issue...STAY TUNED!!! Pictures anybody?!?!?



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