1997 GMC Yukon Sometimes truck will start, sometimes not.

BALLA4LIFE2369

MEMBER
1997 GMC YUKON
V8
4WD
AUTOMATIC
174,000 MILES

Hi, I have a 1997 2door GMC yukon. So whats been happening is ill put my key in, and when I turn it to start it up, nothing will happen. The radio and everything else will turn on but the engine wont start. I have had the starter replaced 3 different times as well. Sometimes when I turn the key many times it will finally start up. Today I went out and it started up fine, but when I was going to head home, when I got in, the truck wouldnt start. I tried turning the key multiple times and it still wouldnt start. And when this is happenig you do not hear anything happening in the engine. I also tried putting it in nutrual and drive and then starting it but nothing. What usually happens is when I let it sit for awhile it will start up like it did tonight about 3 hours after I left it. I'm wondering what is the problem? Do I need a new ignition switch or something else?
Thank you for your help!

1 Reply

MATHIASO

MECHANIC
1,209 POSTS

Hello balla4life2369

The ignition switch is most likely the problem but before assuming that it is good idea to check everything. Check for loose or corroded battery cables (Inspect, clean and tighten BOTH ends of BOTH battery cables).
Bad starter relay wiring connections or ground connection (Inspect, clean, tighten wiring connections).
Bad starter relay/solenoid (Check for voltage at relay, if relay has voltage but there is no "click" when key is turned to start, replace relay).
Bad starter (Jump battery voltage direct to starter to see if it spins, or remove starter and have it bench tested at auto parts
store).
Bad ignition switch (Check to see if voltage reaches starter relay/solenoid when turn to start. If not, check for open P/N switch. Replace ignition switch if defective).
Use test light or voltmeter to check for voltage passing through switch when ignition is turned to start.