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I have a 2001 gmc sierra 3500, lb7, cab chassis with a

Customer Question
wrecker body. Here is...
I have a 2001 gmc sierra 3500, lb7, cab chassis with a wrecker body. Here is my list of issues that just started:
1 When pto switch is turned on it engages the pto but does not increase the rpms, like it typically does. For awhile (couple times) I was able to use the cruise to increase the idle. Now even that doesn't work.
2. When the left turn signal is turned on it stays lit up and does not flash. Sometimes when you have the pto switch on and you turn on the left turn signal it will increase the rpms.
3. When you turn on the right turn signal it flashes fast (like when a bulb is out) all the bulbs are working.
4. When the 4 way flashers are turned on and the key is off they work normally, if the key is turned on they stop flashing.
What I have done so far:
Fuse checks
Replaced the flasher module
Replaced the blinker switch.
I don't want to keep throwing parts at this.
Submitted: 7 months ago.Category: GMC
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Answered in 15 hours by:
11/22/2017
GMC Mechanic: Pete, GMC Mechanic replied 7 months ago
Pete
Pete, GMC Mechanic
Category: GMC
Satisfied Customers: 32,903
Experience: GM training and dealer tech for 14+ years. Diagnostics
Verified

My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

From what you have described here this sounds like a poor ground feed issue.I have seen poor ground feeds cause issues with lights and other components from working properly.I would say most common is grounding under the vehicle on the frame usually at the rear where any trailer/pto wiring is located.I would check and see if any ground issues are found like any damaged grounds or corroded grounds needing repaired.If this is or was already checked and found o.k. let me know.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated ( should be a link to click on here or above).You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

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Customer reply replied 7 months ago
Pete,I have not reviewed your answer based on the following observation; it was obvious from my problem I had a wiring issue, and your responded with you have a wiring issue. It wasn't helpful and did not help solve my issue. I should've known better than to ask the question as it is not something that is solvable over the computer. I will not provide you negative feedback as you did the best you could with my description, I would've been better to not ask the question.
GMC Mechanic: Pete, GMC Mechanic replied 7 months ago

I apologize if I was unable to pinpoint/help with this fault here.If there is anything else I can help with on this here let me know.

Thanks Pete

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