My high mount 3rd stoplight quit working so I replaced it with a new one from Advance Auto, $67.00. I'm tryng to repair the old one for a spare. I took it apart and it appears that water got in it and shorted it out. The diode was in 3 pieces and corrosion was present when I opened it up. All the bulbs and other connections look OK. Does anyone have any idea as to what specs a replacement diode would be? Radio Shack has several you would solder into the circuit but I don't know the exact one to buy. Any ideas? Thanks in advance for any advice.

KO

 

HMMM- Interesting...I've replaced many of these and as a ham radio operator who is constantly fixing wierd stuff,I never considered rebuilding one of THESE! What I have found is that when you get the new one in-make sure that your install is totally moisture proof! Use silicone if need be;espescially on TOP of the screws that hold it to the gate!
It seems to me that this is where water gets in and causes the diodes to fail! Never had a "come-back" repair utilizing this method! Just a thought!

 

You can be sure I used clear silicon to seal the new one up, on both ends that slide on and the screws. I am guessing the many trips through the car wash pushed water into it and in the rear hatch push button switch. I replaced that switch a few weeks ago, $39.00 and about 30 minutes time. I think I'll try a heavy duty 12 v diode and see how it goes. Tx for the reply.

KO

 

Follow-up. I got a diode from a local electronics repair shop (1N5408) and soldered it in. It bench tests fine, all the bulbs light now using a 12 v power supply. A Radio Shack (1N5402 is similar). I don't know if this is a permanent fix because I could not locate an OEM part number. I kept it connected for about 30 minutes and it was still working when I cut the power. It will be a spare if needed.

 

Good Job! You have more patience than I do! In my line of work-I come across alot of these and save every one I can

 

While you still have it apart (if you do anyway), could you snap some pictures and do a writeup about it in the Article Submission/Discussion section?