4-High Mod Overheating

Hey everyone I'm a little perplexed, here's my issue:

Today I bought some diodes from Radioshack, the same ones that are used in the how to for this mod(the one that 99Yuk wrote): http://www.radioshack.com/product/index.jsp?productId=2062579

I soldered it in and all the good stuff and it worked fine, but the diode itseld started to overheat immediately, in about 40 sec it heated up to about 198º! and the heat shrink started to fizzle on me! I have absoutely no clue what I did wrong, can someone help me here?

The truck is completely stock, no HIDs or anything and it wasn't even running, that was just off battery power.

That to me, is the sign of a dead short.

Can you post pics of the install?
What color wires did you solder the diode to?
Is it possible a solder stub is sticking out past the heatshrink to touch the body and ground out?
Didn't this blow out your headlight fuse?

EDIT: Sorry. I reread your post again.
I don't think it's a dead short.
The diode is acting like it's handling way more than 3amp continuous and 200amps peak.
What kind of light bulbs you got in there?
Possibly bad light wiring. Something is causing current from the lights circuit to go to ground. Not enough to dead short it, just enough to cause more than 200amp draw... Almost like a dirty conection somewhere.

I've got silverstar ultras in the low beams and high beams are OE, maybe the silvertsars are the issue? I'm sure the run hotter than the stockers, but I don't think it would cause that much of a draw on the diode. All of the harness is stock and untouched, so who knows what may be wrong in there. However, the mod worked, all four went on. I soldered it between the tan and light green wires with the band facing the tan wire so they all light up with the highs on. It's not my first time soldering either so I know it made a good connection. I don't think its a dirty connection anywhere, after driving around with the highs on for a while the wires were fine, same with the lows. I'm just really confused as to what could've caused that.

I wish I could've posted pics of the install but I didn't bother taking any, and I didnt have much time either (weather started to get bad) so I just desoldered it, taped everything back up to stock, and left it since I'm gonna need the truck early in the morning tomorrow.

i just bought the biggest damn diode they had when i did mine, although mine's a little different with hid's and relays. my diode is only drawing the trigger amperage, not full line amperage, but i think they were in a 2 pack and probably grossly oversized. but, they work, may consider upping the ante and getting a bigger diode. worth a shot.

branndon_b said:

i just bought the biggest damn diode they had when i did mine, although mine's a little different with hid's and relays. my diode is only drawing the trigger amperage, not full line amperage, but i think they were in a 2 pack and probably grossly oversized. but, they work, may consider upping the ante and getting a bigger diode. worth a shot.

Click to expand...

thats a problem. Just because the diode is big dosent mean it capable. You need to figure out the voltage and actually know the value of the diode can handle

He used the same diodes that the rest of us are using. So I couldn't figure out what the difference was between his setup and ours.

I think I may have found the problem.
We all use a relay for our lows. So the diode only has to pass through the relay trigger amps as Branndon_b suggested.
A quick google check HERE confirms that each Silverstar Ultra consumes 4.3amps.
So we are asking that diode to handle 9amps(possibly more on bulb warmup). It's a 3amp diode, and it's fritzing.

So your solutions are;
1) To buy Hid's for your lows with a relay kit. (best choice )
2) To install a relay kit for your existing lows
3) To install more of the same diodes in parallel. (3 should be ok, but 5 or 6 would be better)
4) To buy a 10amp or higher diode.

Just my $0.02.

Would it not be safer and more technically correct to use the relay method?

Well I've tested it and I get 9.63 amps going through there with both on. I think I'm gonna go with a relay...


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Hey, thanks for the feedback! I'll update the 4-hi mod info..

The relay kit will work great... It will make your lights brighter too.

Sorry guys been a little busy lately, but thanks for the help everyone. Probably would've burnt my truck down before I sorted it out if I had to do this myself!