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Joshua Haynes
Joshua Haynes,
Category: GMC
Satisfied Customers: 276
Experience:  Lead Technician/ Manager at Precision Tune Auto Care
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I have a 2008 gmc sierra 2500hd 6.6 4×4 and it will not

Customer Question

I have a 2008 gmc sierra 2500hd 6.6 4×4 and it will not crank brand new batteries turn the key on lights on the dash come on but as soon as u turn to start it won't do any thing any suggestions?
Submitted: 1 month ago.
Category: GMC
Expert:  Joshua Haynes replied 1 month ago.

Good evening! My name is ***** ***** I will assist you

Expert:  Joshua Haynes replied 1 month ago.

Is there any indication of a clicking or thud or any noise at all when you turn the key on?

Customer: replied 1 month ago.
No thud just the sound of like a fan coming on and the dinging noise
Expert:  Joshua Haynes replied 1 month ago.

As you hold it in the "start" position, do all of the lights on the dash go out and the dinging noise stop?

Customer: replied 1 month ago.
Expert:  Joshua Haynes replied 1 month ago.

Do you have any electrical equipment like a test light that you can use to test the starter with my help?

Customer: replied 1 month ago.
I have a volt meter
Expert:  Joshua Haynes replied 1 month ago.

Awesome, if you are able to get to the starter, there is a pretty simple test that you can run to see if it is getting its signal. Do you have a way to get to the starter and either an assistant to turn the key while you are down there or a long enough test lead to attach on the starter while you have the meter inside with you and you turn the key?

Customer: replied 1 month ago.
No it's just me
Customer: replied 1 month ago.
don't have that long of leads
Expert:  Joshua Haynes replied 1 month ago.

ok, that makes it a bit more difficult... there is a more "shade-tree" way to see if the starter is the problem. If you have a hammer, you can hit the case of the starter with medium force several times and try again...

Expert:  Joshua Haynes replied 1 month ago.

If it starts after this, then you have a bad starter whose internal magnets are sticking to the case. If it does not start you will need to try to get a helper to run through some tests to either prove that the starter is bad or to rule it out and move on to the rest of the testing that would be required to find the problem.

Customer: replied 1 month ago.
Me and my dad checked the starter the other day and he said it wasn't getting any power when I turned the key but I'm not for sure if he checked the same thing u r talking about I'd say he did tho he has been a mechanic all his life we r just kinda blind with the newer electronic aide of vehicles
Customer: replied 1 month ago.
Side*
Expert:  Joshua Haynes replied 1 month ago.

Ok, that is the test that I was referring to. If he checked and there was no signal to the starter on the small wire, then it is very likely that you have a security problem or possibly an ignition switch or fuse problem. Have you checked fuses yet?

Customer: replied 1 month ago.
Tried to but didn't know which fuse to check
Expert:  Joshua Haynes replied 1 month ago.

I will check to find out what fuses control that circuitry

Expert:  Joshua Haynes replied 1 month ago.

Ok, buddy, I have a few for you, are you ready to check some fuses and swap some relays?

Customer: replied 1 month ago.
I'm ready lol it's dark here but il do my best
Expert:  Joshua Haynes replied 1 month ago.

I have attached the diagram for the starting system. It includes the starter relay and the starter fuse.

**check fuse number 60 (40 amp) in the under-hood fuse block

**replace the relay labeled starter with anothe relay of the exact same type, perhaps the horn if it matches

Expert:  Joshua Haynes replied 1 month ago.

Let me know how it goes and if you have any questions! Please remember to leave me a positive rating!

Customer: replied 1 month ago.
I believe that's the wrong circuitry because 60 dosnt even have a fuse in it and I did try switching relays didn't change any thing
Expert:  Joshua Haynes replied 1 month ago.

You are looking in the underhood fuse box, right? And making sure I have the right vehicle: 2008 GMC Sierra HD 6.6L diesel

Customer: replied 1 month ago.
that is correct I put a 40 amp fuse in that soot just to see and had no luck
Expert:  Joshua Haynes replied 1 month ago.

Is there any way that you can send me your VIN number?

Expert:  Joshua Haynes replied 1 month ago.

Has your radio clock reset?

Customer: replied 1 month ago.
Naw prolly not tonight idk where it would be at and I'm not for sure I came in the house where would the vin number be located?
Customer: replied 1 month ago.
My clock hasn't reset
Expert:  Joshua Haynes replied 1 month ago.

The vin number is ***** two places that you should be able to see easily: 1) at the edge of the dash all the way at the windshield at the bottom on the driver's side corner and 2) on a sticker on the door jamb for the driver's door

Expert:  Joshua Haynes replied 1 month ago.

You should check the following when you are ready:

1) remove both battery terminals on both batteries and make sure that they are clean and tight

2) is the security light on?

--> an easy reset procedure for a security problem involves turning the key in the "on" position for 10 minutes straight and then trying to start the truck

3) There should be two large gauge wires going to your starter from the battery (I think the battery on the driver's side) and they both need to have power at the battery and the starter. There is a fusible link in the middle of one of the wires, and they are prone to burn out.

Customer: replied 1 month ago.
Hey man I'm gonna try that stuph in the morning will that be okay?
Customer: replied 1 month ago.
1gthk23648f110955 I think that is the vin number
Expert:  Joshua Haynes replied 1 month ago.

Let me know when you have done the other things I mentioned

Customer: replied 1 month ago.
Every thing but the fuse I couldn't find it would it be closer to starter or battery?
Customer: replied 1 month ago.
I have done every thing I have power coming to the starter no power on the little wire
Customer: replied 1 month ago.
Could it be key switch?
Expert:  Joshua Haynes replied 1 month ago.

I am so sorry, I didn't see where you had responded...I think that my system must have frozen on your last reply asking to do it the next day.

Yes, it could be the key switch. If you are not getting any power to the signal wire on the starter, you should begin to trace it up from there. The next easiest place to check would be the starter relay. You want to see if when you turn the key to the "start" position, you are getting power. If not, you would then begin making your way up to the switch.

Customer: replied 29 days ago.
Could u tell me to replace this switch...i have the bottom plastic piece off and the plastic piece around the steering column removed can't figure out how to get that little box out tho