2005 GMC Yukon 6.0 engine, clicking sometimes when trying to start, and not cranking the engine, began last week. I cleaned battery terminals, tested battery voltage under load (about 11 volts), no improvement. Got it started, had 1.5 year old O'Reilly battery checked out by them, checked fine. Had Autozone across the street check battery, also read fine. Autozone said my starter was theirs, and lifetime warranty, so ordered a free replacement starter for me.

In the meantime, I swapped the parking light relay and the starter relay as same part, and I disconnected and cleaned (steel wool) the three big wire connections on the fuse/relay box, then re-connected the battery. Charging voltage is 14.5 volts, so alternator charging.

Anyway, since doing that, Yukon as started every time, but like I said, it's an intermittent issue, no smoking gun found. So I plan on installing the free replacement starter tomorrow. Any ideas?

 

Clicking is indicative of not enough power reaching the starter solenoid. Make sure that all ground connections are clean as well. There are several. I am not looking at a wiring diagram but generally there are grounds from the battery to the engine block and frame. Check the starter to see if it has a separate ground wire.

Rick

 

if you perform voltage drop test on the starting insulated and grd circuits, it will confirm the battery cables and connection are good or bad. a starter draw test will determine if cranking amperage is excessive.

 

Today I installed the free replacement starter from Autozone (was 7 years old). I cleaned the wire terminals real well too. So we'll see if that eliminates the issue; if not, will suspect high resistance in the electrical part of the ignition switch.

I did break a spark plug wire somehow, don't even remember touching that; anyway, O'Reilly had replacement wire in for me by 2pm (part #349V, from AC-Delco). I also bought a 25-pack of 8mm panel retainers for the fender well cover (DIS 1860PK).