Electrical Problem
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Mountain Pass
Joined: Nov 2016
Posts: 195
Likes: 2
From: AK
Electrical Problem
I've been having an electrical issue for the past few months that I've decided to address now that the weather is getting a little warmer.
What happened is the left turn signal was blinking fast, so I assumed bad bulb, and later that day it stopped blinking fast and now I press the lever down to indicate a left turn and there is a quite loud buzzing sound. Sounds like it's coming from where the relays are, but I've replaced them and the bulbs and still nothing has changed.
I've also replaced the multifunction switch to see if that was an issue, but a new one did the same thing so I returned it.
Running lights work all around, but now there are no left blinkers, and also my left brake light doesn't come on. Pulling a trailer I have the same problem, I had the plug tested and only 3 of the pins have anything to them.
I know nothing about auto electrical systems. So I'm in way over my head here.
What do y'all need to know to make any educated guesses as to what the issue(s) might be?
What happened is the left turn signal was blinking fast, so I assumed bad bulb, and later that day it stopped blinking fast and now I press the lever down to indicate a left turn and there is a quite loud buzzing sound. Sounds like it's coming from where the relays are, but I've replaced them and the bulbs and still nothing has changed.
I've also replaced the multifunction switch to see if that was an issue, but a new one did the same thing so I returned it.
Running lights work all around, but now there are no left blinkers, and also my left brake light doesn't come on. Pulling a trailer I have the same problem, I had the plug tested and only 3 of the pins have anything to them.
I know nothing about auto electrical systems. So I'm in way over my head here.
What do y'all need to know to make any educated guesses as to what the issue(s) might be?
Cargo Master
Joined: Nov 2005
Posts: 2,767
Likes: 58
From: East Tawas, MI
I would replace the bulbs all the way around. Replace the flasher. If things don't change on the truck side, inspect the bulb sockets for corrosion and check the wiring to both sockets on the left side and use dielectric grease to renew them. Pretty sure there is a relay under the hood for the rear trailer plug. I would swap that as well with another relay (they are the same part numbers)
When you put your hazards on do they work??
Denny
When you put your hazards on do they work??
Denny
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Mountain Pass
Joined: Nov 2016
Posts: 195
Likes: 2
From: AK
I'll take a trip to the shop and get some parts. There is only one flasher right? Blue square thing that plugs underneath the lower center dash plastic? That's what I've replaced but I'll buy a new one again just in case.
So I'll replace that flasher, 4 bulbs, and the trailer plug relay. Anyone know where that's located exactly? Are there any other relays that I should check/replace?
So I'll replace that flasher, 4 bulbs, and the trailer plug relay. Anyone know where that's located exactly? Are there any other relays that I should check/replace?
Cargo Master
Joined: Nov 2005
Posts: 2,767
Likes: 58
From: East Tawas, MI
Yep, you can key on and put on your right blinker on and put your finger on it. I doubt it's the problem if your right side is flashing tho. Just something in the loop that does go bad.
The owners manual gives you a very nice layout of the relays/fuses.
One other thing to check is the trailer plug itself. If somethings amiss in there that would cause this problem.
Where in Michigan are you? I'm in Tawas.
Denny
The owners manual gives you a very nice layout of the relays/fuses.
One other thing to check is the trailer plug itself. If somethings amiss in there that would cause this problem.
Where in Michigan are you? I'm in Tawas.
Denny
Thread Starter
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Mountain Pass
Joined: Nov 2016
Posts: 195
Likes: 2
From: AK
The plug itself huh? So if it's corroded badly enough it could backfeed a short basically to cause these issues? Interesting. I know there's a bunch of crimps back there that aren't waterproof ones for sure. That wouldn't surprise me actually. Maybe I'll replace the whole plug then and properly splice the wires together...
I'm in Perry, small town right in between lansing and flint on I-69
Tawas area is beautiful! I've been through there once driving along the coast. You're 2 hours north of me.
I'm in Perry, small town right in between lansing and flint on I-69
Tawas area is beautiful! I've been through there once driving along the coast. You're 2 hours north of me.
Posting Guru
Joined: Oct 2012
Posts: 1,910
Likes: 2
From: Hat Creek Ca
Also something to consider is the turn signal switch itself. I am not sure if our trucks are this way but multiple functions are switched through the multi function turn signal switch. IE: brake, tail, turn signals and sometimes running lights. I found out the long hard way.
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Mountain Pass
Joined: Nov 2016
Posts: 195
Likes: 2
From: AK
If you read the original post, I did try replacing the multifunction switch (turn signal, wiper control, etc.) but it didn't do anything different when I installed it, so I returned it, as it was a $50 part or something like that. Seems like the old one is working just as a new one does.
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Mountain Pass
Joined: Nov 2016
Posts: 195
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From: AK
Denny, I forgot to answer your previous question about the hazards.
The dash blinks as though it's working fine, unlike the turn signal indicator which stays lit solid and a constant buzz. The lights do not blink on the front or back though. Looks as though I'm indicating a right turn from the outside.
The dash blinks as though it's working fine, unlike the turn signal indicator which stays lit solid and a constant buzz. The lights do not blink on the front or back though. Looks as though I'm indicating a right turn from the outside.
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Mountain Pass
Joined: Nov 2016
Posts: 195
Likes: 2
From: AK
Interesting. We'll I'll go check those, and all of the above suggestions, and I'll let y'all know what I find.
Will be later on this week. Next couple days are cold
One thing though doesn't make sense with that. The trailer plug issue. Only 3 pins have signal, these are probably non-related then. Not sure how old it is, should probably replace it anyways.
Will be later on this week. Next couple days are cold
One thing though doesn't make sense with that. The trailer plug issue. Only 3 pins have signal, these are probably non-related then. Not sure how old it is, should probably replace it anyways.
Cargo Master
Joined: Nov 2005
Posts: 2,767
Likes: 58
From: East Tawas, MI
If you have any issues with the wiring on the trailer plug, it will translate to your immediate issue.
It's in the loop. Easiest way to figure this guy out is to crawl under the rear and search for the harness plug and disconnect it. That will divorce it as THE problem.
Denny (cold??) lol
It's in the loop. Easiest way to figure this guy out is to crawl under the rear and search for the harness plug and disconnect it. That will divorce it as THE problem.
Denny (cold??) lol
Thread Starter
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Mountain Pass
Joined: Nov 2016
Posts: 195
Likes: 2
From: AK
Hey give me a break haha I lived in Texas not too long ago... I would if it was a major issue but I can wait a couple days since Friday it's in the 60s 
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