Reverse ligths, 6 blown fuses

[K Stokes]

Would a bad "Digital Transmission Range Sensor" cause this?



Background:



2003 XLT 4X4; I have aftermarket parking sensors, (6 years) and aux reverse lights, (5 years). Today I disconnected both to see if I could isolate the problem.



While repairing the license plate lamps, (thx EddieS'04 & Steve M) on my wife's Trac I noticed that the reverse lights were not working...I checked the fusebox and sure nuff fuse # 20 (15A) was blown. I replaced it and the lights worked...long story short over the next 5 days I've replaced that fuse five more times!



I've checked the wiring for a bare wire rubbing, and everything looks good. I've cleaned the connectors, and cleaned up the grounds...no joy. The fuse does not blow immediately...sometimes it will last half a day or so...other times it will only last a few power/reverse cycles.



I've located some pin checks for the DTRS, but won't be able to do those until Saturday. Any thoughts would be greatly appricated.



Thank you,

:haveabeer:

 

[Gary DiPietroSr]

You might have a high resistance short to ground, or like you said a intermittent dead short that happens when you are driving. Is 15a the correct value? Do you have an amp meter to check the current draw while the reverse lights are on? As everyone knows, these types of problems are a PITA and the hardest to find.

 

[Craig Martin 2]

I had a wiring issue last year....couldn't figure out why my dash lights kept blowing....cost me just under a grand and 3 days without my trac. I had one wire behind the tail light pinched and it was touching bare metal and blowing a fuse. It was totally weird that the one place I didn't think to look was causing such a huge issue.

 

[scott degroot]

Look for rubbed through wiring at the trans range switch first. Also pull the connector and check for corrosion and or fluid. You must be having shifting issues also aren't you??

 

[K Stokes]

Ouch, a $1000!



I've run the wire once looking for a nicks in the sheilding, but I'll do it again. I'm pretty sure that the 15A fuse is correct. I measured the load on the circuit at 7.5A, however when I was putting things back together I noticed that the reverse bulbs, (2 LED lamps) were sitting on the top of the tonneau cover...so I guessing there is a bit more draw.



It's the wife's truck I only drive it once a week and not on the highway, though the shifting seemed a bit clunky but I can be sure... I plan to get it up in the air Sat. so I can check the the DTRS more closely.



Thanks for the help so far...

 

[K Stokes]

Before the weekend bump...Thx

:haveabeer:

 

[Bob McDonald]

My son once had a problem where the fuse to the rear light would blow immediately (don't remember if it was tail or brake light ). The problem turned out to be a defective bulb that was shorted internally.

 

[K Stokes]

Just to close the loop on this problem: Turns out it had nothing to do with the reverse lights other than it was on the same circuit...



After several weekends of this kicking my butt, replacing the DTRS, and tracing all the wiring back to the lights a mechnic friend pulled the wiring diagrams for me...turns out the O/D switch is on the same circuirt. Traced the line and found a nick in the shield in the steering colum! Problem solved...