I posted on a few other sites but maybe someone here can shed some light for me!
Well, lets see if anyone can help me with this problem. I have a 2003 Volvo S60 T5 that I bought from a co-worker. He was the original owner. My friend was having a couple issues and decided to part ways with the car. First issue was a intermittant drivers information module. I took it out and had it fixed. Now the other problem.
I have had the car a couple weeks and have had a couple intermittant no start issues. I just went thru this with my daughters 02 S40 and it ended up being the park/reverse/neutral switch. So, that is what my first conclusion arrives at: PNP switch. I changed it yesterday and right after finishing the job, I started it up. Ran it for about 10 minutes and turned it off. Now I get NO start at all. All the lights come on, radio, etc and when turning key headlights go out. No click or anything. Battery terminals are pristine. I took wires off starter and cleaned them up even though they looked excellent. First owner had the battery and starter changed less than a year ago. I tried a different key along with locking unlocking door trick, no luck. I suspect immobilizer ring but not sure if thats it. What about ignition swtch, could it also be bad? Can I just change that or does it invlove new keys with programming? One other concern is I took lower plastic piece off of steering column to get a look at the immobilizer ring. When I removed the 3 torx screws and lowered plastic piece I seen a piece of metal with a spring on the end of it. It's approx one inch long. I looked and can't see where that could have came from. Any ideas? Thanks!!!

 

Here is a update. I changed the antenna immobilizer ring, no change still no start. Changed the electrical portion of the ignition switch, no change no start. Pulled the starter and had NAPA test it. They said spins good but bendix doesn't extend. Autozone tested it as I watched and it tested ok as I watched it spin freely. Ran jumper wires to thestarter and tried the key. Starter engaged properly. Re-installed the starter and it started up. I let it run 5 minutes, shut it off and got the infamous NO START! Any other ideas???

 

I was unsure whether to post my response at first since I imagine most people would react with a "WTH?" reaction. But hey, you've tried almost everything else.

I have similar no starts on mine, every time (at least 30 times over the last 3 years) it has been the small lead on the starter actuator. When I was trying to find the culprit I went through the same checklist as what you have done. I was about to replace stuff left and right until I found the problem. I think the disconnect at the end of the wire has loosened or widened up. So when I pull it off the terminal and slide it back in place and jiggle it a bit, it fires right up.

I should probably fix that.

 

Thanks for the response. This car has been sitting dead for too long now! I will go out tomorrow and try looking at the small lead you are talking about. If I hadn't just went thru the reverse neutral switch on my daughters S40, I probably wouldn't have jumped so soon to change this one out. I hate part swapping as it's just a guess.
I have a question. Is there supposed to be 12 volts all the time at the starter where the 2 big cables bolt on? I thought only when the immobilizer and relay an "ok" to start condition. I have 12.30 volts with the key on or off.

 

You should have 12 volts at the starter. It comes straight from the battery I think. It's the ignition that provides the switched power for the solenoid to activate the starter. The same principles as a relay but on a larger scale.

 

So, if I were to put my meter between the positive cable on the starter ( coming from battery) and the small wire that plugs into the spade on starter ( that must go to relay you speak of) then I should have 12 volts when the key is on, correct? Otherwise the relay is open, that little wire won't be grounded and no circuit, no volts. Gonna go try it!