The multifunction switch can fail in some strange ways. Before replacing it double check the fuses. With a meter make sure you have voltage at both of the pins on the top of the turn signal and hazard flasher fuses with the key on. Another failure is corrosion in the junction on the frame by the spare tire where the trailer, left and right rear lighting harnesses plug into the feed from the front of truck.

If you need to replace the multifunction switch use only OEM.

Ted

 

I think he did Ted.

OP, talk to me about fuses. You tested them, which one and how?

 

I visually inspected all of the fuses, did not test each one. The truck is at home right now so going by memory. The info I found is that the blinker/hazard are on the one solenoid under the dash on my truck. There are no fuses marked for turn signals in the under hood fuse compartment. There is a ignition solenoid that brings power with key turned on so I replaced that one as well. I have voltage coming in to the switch with the ignition on. I did look at the wire junction at the rear of the truck, rattled it around a little but did not unplug and replug it. I will check that connection when I get home. I will also check for voltage but I am pretty sure I am as the hazard lights work.

 

Unplug all at junction at rear, check to see if dash lights are normal,rules out front of truck,had one like that,a time ago, but I think it was back feeding power

 

Thinking more on that,center pin was used for aux. Power,and somewhere it bridged,bad connection,or good connection, for the wrong purpose,un plug and try to isolate

 

If the wiring at the rear was a problem, the flasher would likely still flash (fast, but still flash).
A ground on these wires, at the rear, would cause a fuse to blow.
The trailer wiring, if factory, should be separately fused so the truck flashers will continue to work.

I don't have a wiring diagram for you truck and you may be right that there is only one flasher. However, the signals share a lot of components with the hazards. If the hazards work, I'd suspect 2 flashers, if all fuses are good.

And again, I don't have a wiring diagram; but some of your fuses are in an inside fuse panel, probably in the dash.

 

Yep,a single flasher for both, back feeding will cause a lot of different issues, like he stated, flasher works but no instrument panel lite,so ground could be out of the problem

 

Ok, let's go with the one flasher idea....

@jjub when you use the hazards, is everything normal? Do the dash indicator lights flash with the exterior lights?

 

What trailers are you talking about"if factory, should be separately fused"?

 

Factory towing options have separate fuses for the truck and the 7 way trailer connector.

Ted

 

Thanks all, did not get home till after dark yesterday so I was not able to do any more testing. There are no fuses under the dash, all in the engine fuse compartment. The hazard/turn signal solenoid is under the dash. The hazard lights both on the instrument panel and all four corners of the truck work normally. As far as the trailer connection, I do not believe it is factory, pretty sure a previous owner installed it. I have used it several times since I owned the truck and had no issues. Was hoping I would not have to disconnect the trailer wiring to see if something went wrong there but may have to. Just a tedious job.

 

Not a tedious job. If it's factory the three harnesses will unplug from the junction. If it's rigged to the tail light wiring then the left and right wiring harnesses will unplug from the junction.

Ted

 

For troubleshooting you can disconnect the harness from the front of the truck instead of the left, right and trailer harnesses. You might also want to permantly eliminate the rigging done by the previous owner and install a factory trailer harness. This comes with the twist-in 7 way connector and should prevent future wiring problems. They are available at etrailer.com and 1A Auto, one of our site sponsors. The video will help you locate the junction and unplug the harnesses.

Ted

 

Grasshopper, I could walk away from this threaded and maybe you would take the time to listen; but you may never find it.

So, open the driver's door, at the end of the dash you have a removable access cover, remove it and you will find a fuse panel.

You will also, if you look at the cover, a fuse chart. One of the fuses is marked TURN, take a look at it.

 

There is a fuse panel under the dash on the drivers side. This is where the hazard/turn signal relay/ solenoid is located. There are no fuses in this compartment. The fuses are all located in the engine compartment fuse box. I previously said there was none marked hazard/turn signal. That was incorrect. There is a 30amp fuse in the engine bay compartment marked hazard/turn signal. I had replaced this fuse on the first try at finding the issue as well as replacing the solenoid under the dash.
Yesterday I rechecked my engine bay fuse panel and I get voltage at all fuse "plugs" including the 30 amp hazard/turn signal. I pulled the fuse box apart and inspected the underside of the fuse box to make sure some critter did not get in and build a nest or chew things up. I stuck a new 30 amp fuse in just for kicks. I also disconnected the 7 pin trailer connector as well as the after market brake controller to rule them out. I also unplugged the factory wiring harness connector at the rear of the truck, and replugged it.
On the multi function turn signal switch, I get voltage for the hazard functions, wiper functions, hi low beam and horn. Then there are 3 contacts that I am thinking are for the turn signal. The center gets voltage when you turn on the ignition and I would think the contacts on either side would get voltage with activating the turn switch lever, but they do not. On the 4 pin solenoid contact under the dash, I get voltage on one of the pins when the hazards are activated but nothing with the turn signals.
The other thing that happens is when I apply the brakes and activate the turn signal, the corresponding brake light goes out. This tells me it is getting the signal from the switch, but not blinking. Also tells me the brake light switch under the dash is working??
Sorry this is so long, just trying to give as much info as I can.

 

Not 100% sure but you could have a bad hazard switch as I think the turn signal power and flasher output goes through it.
Correction: if fuses are good.

 

That is not a fuse panel under the dash. It's the Mid Buss Electrical Center that feeds power for doors, seats, etc. The interior fuse panel is at the driver's end of the dash behind a removable cover. Just pop the cover off.

Instead of posting the video for locating the interior fuse box I'm posting the link which also has some wiring diagrams.

https://www.carcarekiosk.com/video/...2000_Chevrolet_K3500_6.5L_V8_Turbo_Diesel_Cab_and_Chassis/fuse_interior/replace

Ted

 

Thank you Ted, I've been trying to get him to look at this fuse panel from the get go, he only wants to argue.

Perhaps if he took the time to read his Owners Manual, he might have fixed it long ago.

Anyway, I've had enough, I'm out of here.

 

If your turn signal fuses at the end of the dash are good you either have damaged wiring inside the steering column or you installed an aftermarket multiswitch instead of OEM.

If you have a tilt steering column one or more of the wires for the multiswitch has/have opened inside the insulation. You won't be able to tell by looking at the wires.

Many have had problems trying to use aftermarket multiswitches with varying functions not working. Their solution was to install an OEM multiswitch.

Ted

 

Well F me. My apology to Ray. I was looking under the dash. Ray did write "at the end of the dash" and it did not sink in. Was not trying to argue, just kept thinking of the panel under the dash.
Thank you Ted, it took a picture to get thru to me.
I will check when I get home and my thanks to all.
Joel

 

Ya know, I aint no spring chicken. Ive owned chevys, fords, dodges, toyotas, datsun, Izuzu, and several jeeps, but right now I feel like an amateur.
I just did not know that fuse box was there. Sorry for wasting your time and mine.

 

Ya know, I aint no spring chicken. Ive owned chevys, fords, dodges, toyotas, datsun, Izuzu, and several jeeps, but right now I feel like an amateur.
I just did not know that fuse box was there. Sorry for wasting your time and mine.

hey, not to worry, I was just getting a little frustrated that you were not reading what I was typing. All is good, we've all been there.

Big question though, did finding the fuse panel help solve the problem?

 

Not a waste of time JJub. Learning is never a waste in my opinion. Now that you are experienced I'll bet you may be able to help others at some time. Just imagine how much a service place might have charged you to learn about your fuse box.