Trying to pick my way though a crank, no start diagnosis. sometimes it starts first try, but going downhill to where it is very difficult to start.

ignition coil, cam and crank sensor replaced. New plugs. Cap and rotor look OK, No spark. Will not start on starting fluid.

I note that the key tumbler is a bit flaky sometimes and wondering about the ignition switch.

My question is whether bad contacts in the ignition switch can cause a strong crank but no turn over condition.

If the answer is affirmative, I'll take apart the switch and clean it but trying to rule out possibilities first. I can't find a switch diagram online to think this through.

thanks for any suggestions!

 

What year is the car?

...Lee

 

98 V70 non-turbo

I pulled out the switch this evening, opened it and cleaned it with contact cleaner.

Got too dark to see before I could reinstall to test.

I read somewhere that voltage drop in switch due to dirty contacts could cause incomplete starter action...hence my question.

The contacts didn't look too contaminated. Appear to be gold plated. And the switch does seem to be well engineered and well made.

Just trying to do what I can do before I tow it into a shop!

 

If you still suspect the ignition switch pm me with an email address. I have a copy of the pin-outs and a truth table but the file is too large (276 kB) for this site to handle.

...Lee

 

Thanks for kind offer, Lee.

The engine turns over fine starting with a screwdriver using the cleaned switch, so it appears that maybe was the problem. It was very close to turning over but didn't quite pull it off before.

Unfortunately, now my power windows and radio don't work! Hahaha! Those switches were not meant to be dismanteled and repaired. Put in an order for an OE replacement this afternoon.

Might still have to take you up on the diagram but let's hope not!