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Discussion Starter #1
I've noticed a problem with my turn signals, where they shut themselves off when sitting with the blinker on waiting for a turn.

I figured it was the multi-function switch or the connector for it so replaced both of those a few weeks ago. I suspected the connector because when I added turn signal mirrors, I spliced into the wires just behind the connector and broke off a couple of the terminal keepers in the connector body when I unlatched the terminals to slip heat shrink over them.

But apparently the multi-function switch and connector weren't the problem, because it's happening again. :frown2: The only thing I can figure is the flasher is getting weak, but I wouldn't think that it would turn off the signal lights when it failed. Wouldn't they fail ON if the flasher died?

Anyone have experience with this? Any comments are welcome. I'd like to have a better idea what to look for before I go diving under the dashboard to replace the flasher.
 

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Exactly how do they "shut themselves off"? Does the lever move back to center? Or do they just stop flashing while the lever is still in the turn position? Always from the same direction? Or from either direction? How long does it take while sitting still? Will it do it in Park if you're NOT touching the steering wheel?
 

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Exactly how do they "shut themselves off"? Does the lever move back to center? Or do they just stop flashing while the lever is still in the turn position? They just quit blinking. The lever stays where it is and they just stop flashing. Sometimes I can push the lever in the same direction and they'll start back up, but sometimes I have to recenter the lever and move it back into turn direction for them to start up again. That's why I focused originally on the multi-function switch.
Always from the same direction? Or from either direction? Has happened in both directions.
How long does it take while sitting still? Varies. Sometimes it works just fine. Other times it's within a few seconds and they shut off.
Will it do it in Park if you're NOT touching the steering wheel? Always when I'm not messing with the steering wheel (no park position - it's a manual tranny).
I haven't been able to tell if it happens more when the truck interior is hot or cold. Pretty much has me stumped.
 

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Then it sounds like you have a poor connection somewhere in circuit 44, 294, or (less-likely) 383, shown in this diagram:
http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=66475
There's also a chance it's in 57 between the flasher & G202.

My guess is that, when the circuit is OFF, there's just enough contact for it to come on. But once it's ON and drawing current, the poor connection overheats & burns just enough to shut down the lights until the next OFF cycle. I'd start by allowing the symptom to appear, and then checking voltage on those circuits at SEVERAL locations. If you find one circuit has 2 voltages (with the lights NOT flashing) at 2 locations, you can be sure there's a fault between those 2 locations.
 
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Discussion Starter #5
Thanks Steve

I happens fairly infrequently, so will be a PITA to track down. If it gets any more annoying, I'll dig into it.
 

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The multifunction switch is a likely culprit. The contacts in there can get oxidized and not make good contact. The flasher relay could also be at fault. I hate to just swap parts without testing, but considering how easy it is to swap, I’d be tempted to throw a new flasher in, then swap that multifunction switch.


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Discussion Starter #7
Already swapped out the multifunction switch. It had some other issues like the intermittent wipers not working correctly. That part was fixed by the switch swap, but the turn signal issue came back. I may try swapping out the flasher and see if that helps. Tracking down a loose connection like Steve suggested will be a giant pain, so would rather not have to do that. It's bad enough getting to the flasher.
 

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It’s not too bad. You can do it using the Braille method. Lay on your back and reach up above and midline to the accelerator pedal. You can touch the cover. Squeeze the sides and pull it off. When you pull the relay, make sure and look at the orientation because you’ll have to blindly put the new one in.


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...above and midline to the accelerator pedal.
Don't you mean e-brake pedal? Or are diesel flashers NOT in the dash fuse block?
 

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Discussion Starter #10
Don't you mean e-brake pedal? Or are diesel flashers NOT in the dash fuse block?
On the '99+ Superduty's there's a relay block behind the radio for flasher, fuel pump relay, and (IIRC) trailer running light relay. They put it in a nicely convenient spot for ease of access. :frown2: Can't even see it unless you pull the radio (or ashtray on some earlier trucks like mine that had the cup thrower instead of cup holder).
I've used the braille method before (not in that location) so am familiar with the concept. :winking:
 

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Discussion Starter #11 (Edited)
It’s not too bad.
LIAR!!! :winking: You must have three elbows per arm. :|
Well, I got the damn thing changed out. There was no way I could get to it from above the accelerator pedal. The top is oriented toward the center of the truck. I wound up removing the radio, cup holder, and ashtray and reached thru the ashtray hole while looking thru the radio opening. Took me about an hour. :frown2: If I never have to get in there again, it'll be too soon.

Here's a couple of photos of what I was up against. The first is thru the ashtray opening, with the dash cubby sticking in from the left. The second is thru the radio opening. You can see the red flasher socket WAY down there and the other two half-size relays next to that. [on edit] Stupid iPhone!! Photos are rotated. :thdown:

We'll see if the problem rears it's ugly head again.


 

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Funny, because I just swapped mine the other day when I put LED lights in. Took less than 5 minutes in mine. Must be an early 99 thing...


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On the '99+...
Brain fart... :7: I totally spaced out on the year. I have a bad habit of assuming we're always talking about '80-96 trucks. :grin2: Just ignore the man behind the curtain. :winking:




But I am seriously considering buying a cab&chassis '02 (I think) F350 dually 7.3L very soon. >:)
 

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Discussion Starter #14
Funny, because I just swapped mine the other day when I put LED lights in. Took less than 5 minutes in mine. Must be an early 99 thing...
The electrical system got changed for '02 models. Maybe they fired that idiot engineer that put the relay block there and put it in a more accessible position. You don't have an under hood fuse box either (not that that's a bad thing).
 

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Never an easy flasher to replace unless you teach your 14 yr. old son how to get his hand in there. Electronic one for sure.

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