W202 oil level light and wiring

[Prickleypear]

I had to replace the core plugs on the inlet manifold side of the engine block on my C220 1995, i knew before hand that the wiring in the engine bay is cracked and the insulation is hard so i took care to bend the wiring as little as possible but one has to bend it to get the inlet manifold off.

So replaced the core plugs re assembled everything then came the wiring, some insulation came off which forced me to to try and re insulate the wiring before reconnecting the battery.

WHAT A DISGRACE as far as i opened the loom the insulation just dropped off the wires, on my W124 the copper broke inside the insulation but this i have never seen before.

To make a long story short i replaced some of the wires and other i re wrapped with insulation tape from one end to the other.

NOW my problem, the oil level indicator light now stays on, i know that the wire is not grounding anywhere since i wrapped it from the unit connection all the way to the connection plug on the inner wing.
BUT it was in the same loom as a positive power wire running to the starter motor and seemed to be touching for a long time.
Could this "short" have kept the light out and damaged the unit in the sump or is there something going on here that i need to investigate deeper?

The oil level on the dipstick is full, and i have never had this indicator light up before except when switching the ignition on as all modern merc do.

Any help or advice much appreciated

 

[190]

can't help with the specific oil level fault other than to identify it on a wiring diagram and trace it out.

You are not lone though. This wiring harness issue is well documented and applicable to your year. Apparently some clown decided it would be a good thing to make bio degradable wiring insulation but got their sums wrong as to how long it would take to degrade. A sad episode in Mercedes quality which I think MB did not fully own up to.

 

[John Jones Jr]

My guess is you have repaired a previous fault in wiring to the oil level sende, now the oil warning light is on because the sender is faulty, which of course you wouldn't have known about prior to repairing the wiring?

 

[Prickleypear]

can't help with the specific oil level fault other than to identify it on a wiring diagram and trace it out.

You are not lone though. This wiring harness issue is well documented and applicable to your year. Apparently some clown decided it would be a good thing to make bio degradable wiring insulation but got their sums wrong as to how long it would take to degrade. A sad episode in Mercedes quality which I think MB did not fully own up to.

at the bio degradable.
I noticed the name "Roche" on one little piece that did not fall off, not that will help with anything just found it interesting to find the manufacturers name

My guess is you have repaired a previous fault in wiring to the oil level sende, now the oil warning light is on because the sender is faulty, which of course you wouldn't have known about prior to repairing the wiring?

That is my thoughts on the situation, well i have always relied on the dipstick so it wont be any different now