I need some help. I have a sl500 that won't attempt to turn the engine over when you rotate the key. After a number of attemps something connects and it starts. The problem is intermitent, days or weeks. I plan to bring it to my local MB shop, but would like your input before the troubleshooting starts.

Thank you in advance


PS Temp hit 50 today in NE. I hit 100mph!!!!!!

Does this happen only when the engine is warm or the car has just been driven?

Thank you for your quick responce. It has happened on both a cold and warm start.

Well for warm starting, it could be the overvolt relay, AKA OVP. This is a very common problem with Mercedes. The relay is only about $50 and very easy to install. Maybe this is where you should start. It solved my warm-engine starting problem.
Wait, do you mean that the engine does not even turn when you put the key in? If so, then it is not your OVP... could be your ignition switch.

Ignition switch is a safe bet. If you turn it to start and you get nothing, no clicks from up front and a couple more twists produce the desired result, then it's dirty or defective. Do you have a heavy key ring? This is a known issue for ignition switches. There could also be a problem with you neutral/park cutout switch , which is located on the trans. If you try to start in park, try putting it in neutral. If that works, see if you can duplicate the problem repeatedly. Then you will have good information for your tech to work with. Troubleshooting labors costs are inversly proportional to the amount of time it takes to solve the problem.

[Edited by jeffsr on 03-25-2001 at 11:06 PM]

yes, I did misunderstand. Very well could be the ignition switch. Like Jeff said, this is a somewhat common problem, esp. with heavy key chains. Clever Jeff; yes do try that with it in Neutral.

[Edited by David C Klasse on 03-25-2001 at 11:11 PM]

I get nothing when I turn the key. No clicks! I DO have a heavy Key ring? It is a 92, first I will attempt to clean it. When it first happened last fall I thought about the cutout swith and placed the car and netural and it started. However, it was just that one time it started. Last fall and today it failed to start in neutral.

If I must replace the ignition switch what is involed?

Larry,

Not too long ago, my ignition switch went bad. It all started when I noticed that it required me to turn the key a bit more forceful in order to get the car starting. Then it ended when the car wouldn't start anymore, where there were no clicks when I turned the key.


A local independant shop replaced my ignition switch. The only draw back was that when I got a new ignition switch, I also got a new key for it. Thus, I needed two keys to drive my car: the old one to get into the car, and the new one to start the car.


Unless, if you don't want the hassle of having two keys, you can change all of the door locks and the trunk locks to match the new key. That sounds expensive............


Happy driving,
vutown

I think the dealership can order it for you with a matched key if you go to the dealer and use the vin number on the car. You might have to fill out some heavy duty paperwork and provide proof of ownership. Check into it, it may help.

Otherwise have the ground wires checked and the wires on the starter to see if they are loose, but everyone else seems to think its the switch, which may just be your best bet.

Alon