Cold Start Valve modification kit HELP!!!!

[wwheeler]

I spent a frustrating evening installing the 108 540 10 09 wire harness and 001 545 16 24 time relay. It is suppose to activate the CSV for just one second above 35*C. Everything seemed to fit OK but it didn't work.

I tried a test light on the CSV solenoid while cranking and nothing. The thing I noticed that was strange was that when I turned the ignition key, there was about a 1/2 second delay before the starter would engage. I did this several times and was always about the same. And engine never started. I then did a diagnosis on the time switch, ground and harness. The time switch checked out perfectly according to the tech manual, the ground wire had a good connection and the harness wires had continuity.

So I removed the mod kit and checked the CSV for power. Cranked the engine very briefly and CSV solenoid had power. I reinstalled the mod kit. I cranked the engine and no power at the CSV solenoid. Now here is the unbelievable part. When I turned the key CCW to stop the engine from cranking, it would NOT stop. I even removed the key and the starter continued to crank! I jumped out of the car ready to disconnect the battery, and the starter stopped. All the while, the engine never started indicating that the ignition wasn't firing.

Again I removed the mod kit and replaced the relay sockets as normal. Cranked the engine and it fired up and ran great. So what is wrong? Has anybody installed one of these kits that can shed some light on the installation? I followed the attached instructions that are very simple.

Thanks for the help!   

[ja17]

Hello Wallace,

Are you sure you are modifying the correct relay?

[wwheeler]

Hi Joe,

Yes. I tested by jumping 12V to #87 on the connector and the CSV solenoid activated. In fact I have been testing that circuit recently, so I am familiar with it. The odd thing about the wire adapter is that only (2) of the four posts are used on the special connector. Having the engine continue to crank with the key out is rather unsettling, so I want to make it sure this was made correctly. Once you find the correct relay, it is very hard to put this together incorrectly.

So the plug on the timer has contacts on #31 which has the ground wire, #86 and #85. The special relay plug only has contacts on #85 and #86. The other (2) #87 and #30 are completely blank. So to me because this special plug sandwiches in between the relay and the main relay plug, #30 and # 87 never reach the relay itself. Aren't those the power supply and lead wire to the solenoid? If they are not connected to the relay, no wonder I never get power to the CSV solenoid.

So to conclude, #31 on the time switch has a separate ground wire that is attached to a ground. #85 on the time switch is connected to #86 on the relay plug. #86 on the time switch is connected to #85 on the relay plug. I checked it twice and that is the way it is. Is that correct?  According to the tech manual and my testing, sounds like the wires are switched.

This came right out of a sealed package from MB that I have had for two years. So it looks like the wires are switched in the plug AND I am missing to jumper posts on # 87 and #30.

Thank you for your help. I am running out of aspirin for my headaches this is giving me!         

[wwheeler]

Quick update. I just looked at a 108 540 10 09 wire harness on eBay. http://www.ebay.com/itm/Mercedes-1085401009-Instrument-Wiring-Harness-/200703065563  The special plug that is sandwiched between the relay and its plug HAS (4) pins where mine only has the two. The attached picture shows my wire harness. Clearly two of the pins are missing.

This combined with the switched wires sounds like my problem. Agreed?

Thanks. 

[ja17]

Looks like you found the problem Wallace.  Its an expensive little item. Maybe someone could make up a good wiring diagram so the correct harness could be easily identified.

[wwheeler]

Seems like the #85 on one plug should be wired to #85 on the other. And same for the #86. If it were just that, I could switch the wires and try it. Unfortunately, the two missing posts are special in that they have the post but also a socket on the other side.

The two missing posts are for the solenoid supply and feed. I'll see what I can find and yes, it is expensive. 

[Brian Davidson]

I had a similar problem a couple of years ago. I fitted the two supplied parts as per instructions in the BBB. On turning the ignition key to start there was a slight delay before the starter motor was activated.  The engine did start but after four or five seconds there was a click from the starter region which I took to be solenoid switching off. On the odd occasion in the intervening years there has been that horrible zinging sound when the starter attempts to engage. I hope the pinnion and/or the ring gear has not been damaged. As I understand it the solenoid has to mesh the gears before current is supplied to the starter motor itself. Hopefully the zinging sound is coming from the oneway clutch. Perhaps Joe Alexander might kindly comment.  Brian Davidson.