Need help, again!
 

Maybe you have read my post yesterday. I am replacing the combination switch on my 88 560SL and at the same time I fixed the nonworking odometer, so the cluster was out. I put it all back together and to my surprise, the car will not crank. I checked all the fuses, pulled the cluster out and reconnected everything, still no cranking. Any suggestions?
I have had the cluster out several times before without problems and I am at a loss to figure out what is going on. The one thing out of the ordinary is that when I put the key in, before cranking, some of the warning lights (oil, windshield washer and brake) will not come on, the rest will, but I do not know what to make of that.
This has been a frustrating project, please help if you can.

Jl

Just a wild ass guess, but could you have shorted a wire while working?

Check all your fuses.

Fuses are ok. I am thinking I may have touched a connector while working under the dash and that might be the problem, so I am going to go over all that I see under the dash. I you have any suggestions what connectors might be involved and where they are, please let me know.

click or anything? if nothing has to be short or shorted relay

Wiggle gear shift lever and/or place in neutral and try again.

Thank you Ron and RM for your advice. The car is running now. I went under the dash again and went over all the connectors once more and after removing and replacing them again the car started fine. Everything works, speedometer, odometer, cruise, all the gages -fuel, temp ... but some of the idiot lights do not come on.
Specifically, high/low beam (unless I pull on the stalk), oil, windshield washer, light failure, SRS and seat belt do not come on. The low coolant light is constantly on (even though the coolant level is fine). The battery, ABS and check engine lighths come on brightly and then go out. The brake and pad lights come on weakly and then go out. After going over the connectors time and time again, my thoughts right now are that I have a ground problem. What do you think? I believe this is a known issue with the cluster so I am doing a search to learn more about it. Wish me luck.
In the meantime, I would appreciate any suggestions/comments, specially from those of you that have been down this road.

Jl

Then again ...
 

After looking at the circuits I think I better pull the cluster and check the bulbs ...

I had a ground issue with the cluster, and many others have had as well. Solution is to add a dedicated ground to the cluster. navigate to The 107SL Source Page and click on the diy link, then the odometer repair link to see one way to add a ground. Checking bulbs is also prudent...

Add a ground....trust me.


Odometer Repair: Tutorial - Benzworld.org - Mercedes-Benz Discussion Forum

The pictures I'd like to post are in the above thread or on this thread:
http://www.peachparts.com/shopforum/sl-forum/308189-another-erratic-fuel-gauge.html

add a ground, as stated, the pod actually grounds to the frame if positioned correctly but after removing it's hard to get it just right , a ground strap is an easy solution, but also check your muti connector to make sure that has not been buggerd with taking on and off

Thank you RM, nobby and Ron for your advice and excellent links. I have been reading up the material and I am convinced. I will be adding a new ground to the cluster. Unfortunately I am so swamped that I will not be able to do it till this weekend.
I the meantime I have been looking at the circuits and I am convinced that my problems are all related to the central square unit at the bottom of the spedometer/odometer. In the 88 SL the unit controls the oil, windshield washer, coolant level and bulb failure lights. It is fed by the X5 connector from the fuse box through terminal 5. Terminal 8 gets power from the voltage regulator to turn off the lights with the engine running ... except for the coolant level that has an additional circuit to the coolant level sensor. The only think that makes sense to me is that a transient/short blew all the bulbs except the coolant that was protected by the collant level sensor (which blew instead, ha ha). Makes sense but probably wrong. Will know for sure saturday.
And I have another head scratcher for you guys. All of you are odometer repair experts so you may have an explanation. I repaired the odometer as per the posted instructions, replaced all 3 gears, and the odo worked fine. Then one cold morning (by Florida standards anyway) with the trip odo reading 113 miles it stopped working. On the trip back from work it started working again. Same thing for the next couple of days. I assumed that the drive gear was slipping so I went back in and I put some epoxy on the shaft and gear. I am positive that the drive gear is not slipping now but I am back to the morning-not working/evening-working routine. Could it be a cold/hot issue? I am totally clueless.
Thanks again for you help. I will keep you posted.

Jl

are you talking about the trip ODO and that it works/does not work, when reset ? that gear can move just enough in its housing to not make contact ,, a little wear in the housing could do it despite new gears .... a long shot but it may actually be affected by heating ( expansion) .

DId you check the traces on the back of the dash pod for continuity? there is a possibility you fried a trace. I did it in a 300D and had the same bulb, and random turn signal issues

Just going out on a limb here, but remember that the odometer is operated by an electric step motor. Since you're having cluster electrical issues, it's possible it could be related to that. Install the new ground and check the connections at the odometer.

I've not actually heard of this issue, but I have read of odometers having a step motor failure.

Ron:
The odo/trip odo do not work when I drive to work in the morning, they work when I drive back. Resetting the trip odo has no effect. Your idea that this is an expansion issue makes perfect sense and is very intriguing, worth some further research. As far as the traces in the back, I have not had the chance to pull the cluster out yet, but I will this weekend. I will be inspecting them carefully as well as the ones in the rectangular unit at the bottom center.
Abiby:
This was happening also before I had the cluster issue so it probably is unrelated. I certainly install the new ground and we will se what happens.

Jl

Did you test those bulbs yet? Last time I pulled the cluster on my 380sl to replace my steering coupler, I lost both turn signal lights and my brake light. Simply turning them around in their sockets fixed the problem. But why 3 of them went on the fritz at the same time when I didn't fool with them at all is still a mystery:confused:. So it is possible that several of your bulbs loosened up when you took your cluster out, and they just have to be screwed back into their sockets better.