LED Turn signal problems
 

I just replaced the old box type front turn signal/running lights on my KW T800 with new l.e.d types. The installation went fine. My problem is that the left and right turn signals front and rear will not work. The 4-ways work fine and the running lights work. Could this be the flasher? I wasn't sure since the 4-ways work. Thanks for any help. 8)

LED's don't draw much current compared to regular incandescent bulbs.

The draw may not be enough to make the flasher cycle properly.

With the 4 ways on the total current draw may be enough to cycle the flasher.

That's true. Is there a flasher or something that would correct this problem? Thanks for the reply!

Try a Grote #44891 flasher - it's designed to work with LED lights.
(that's the 2 pin style which I would assume your truck has, however if you have the 3 pin flasher it would be a Grote # 44890)

Depends on how new the truck is ? My 01 KW doesn't have a flasher like older trucks. I'm not sure how it flashes ?? Solid state ?

I also replaced my square type fender lights with some I got off of ebay. I was real happy with them.
I had to wire them in ( not plug in) but I didn't have any problems.
The rears are LED also. Their a good safety feature.

Edit: my truck does have 4 rear lights, two oval up above and the grote style square ones with the back up lights built in, .their a new Led style too.
I do get a weird double flash from the fender lights and the ovals in the rear. It's a short flash that's instantly followed by a regular flash, it didn't do that before, But it's kinda cool and gets your attention.

Thanks for the info. I purchased a 2 pin flasher online that should do the trick.

The flasher should be located under the dash to the left of the steering wheel column in a pull down compartment (2 screws) in front of the fuse panel. I spoke with a guy who had the same problem (no signals, Quick blinking) and he said that a led type flasher would clear things up for me. I'll let you know how it works.

Thanks, I'll check for a flasher in that location.

What year is your KW ?

I own a 2001 t800

My guess is that you wired the new lights up wrong. You can wire those lights up so you get different results as in one thing working and something else doesn't. I just went through this on my truck replacing the directional lights.
If your 4-ways work then your flasher is good.

And if the lights work when in the 4 way mode, then they must be wired correctly, no?

LED's are polarity sensitive and if hooked up wrong they will not function at all.

I stand by my statement that the LED lights are not drawing enough current to cycle the stock flasher when the turn signals on one side are activated.

When the 4 ways are activated, then the total current draw is apparently enough to cycle the flasher due to the fact that twice as many lights are activated.

We've had this happen in the shop at work just a few weeks ago.

Nope, not true. My 4-ways would work but no turn signals. Then I had it wired where everything worked until I turned on the head lights. Then I had it one way where my leds were not that bright. I went from a 3 wire light to a 4 wire. Come to find out, 2 of the wires were grounds.

It will be interesting to see what fixes the problem!!

Exactly.

Thats because:It sounds like you are referring to combination running lights and turn signals, therefore there would be a power wire and a ground for each function, for a total of 4 wires.

when you had them hooked up so they were dim, that would have been the running light wires , and when you hooked them up so they were bright, that would be the turn signal wires.

When you had it hooked up so it would work except when the headlights were on, you had the grounds inadvertently connected to the running light hot wire, and it was grounding back thru the headlight circuit, until the headlights were turned on, at which time the running light hot wire becomes energized also, therefore eliminating the path to ground.

BTW, I never said the flasher was bad, just incorrect for use with LED lights.

Yes, they are combination running and turn signal lights. At least I only had a few combinations to go through before I got it right.

So what was the outcome? Either your still running with broken lights or didn't post the fix? Just curious???

You should truck repairs Redbank Plains mechanic to help you with that repair on your truck.