SLK/R170: Electrical Earth Issue - ESP/ABS, Tacho, Eng Temp, Oil Level
08-10-2022, 04:03 PM
#1
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R170 99SLK230 + SLK32
Electrical Earth Issue - ESP/ABS, Tacho, Eng Temp, Oil Level
Only When the car is just started - and for the next 5 minutes,
.......The tacho and engine temp gauge needles seem to lose power and drop for a fraction of a second
.......at the same time - the water light and oil light come on
......the abs light comes on but doesnt go off....
this has been happening for a couple of months now - but once the car warms up its fine
My current hypothesis is that they are all hanging off the same earth and its lose.
Reason - if you lose the earth the needles will drop to zero and the 2 dash lights will come on....the ESP/ABS loses integrity but doesnt recover and stays lit
If anyone knows the circuit diagrams and can trace the common cause - much appreciated.
I did replace the headlight switch a few months ago with a 2nd hand one......will follow that route as well.
.......The tacho and engine temp gauge needles seem to lose power and drop for a fraction of a second
.......at the same time - the water light and oil light come on
......the abs light comes on but doesnt go off....
this has been happening for a couple of months now - but once the car warms up its fine
My current hypothesis is that they are all hanging off the same earth and its lose.
Reason - if you lose the earth the needles will drop to zero and the 2 dash lights will come on....the ESP/ABS loses integrity but doesnt recover and stays lit
If anyone knows the circuit diagrams and can trace the common cause - much appreciated.
I did replace the headlight switch a few months ago with a 2nd hand one......will follow that route as well.
08-21-2022, 03:25 PM
#2
Junior Member
Why not add a body ground (earth) to your slk, just take a short length of thick wire run it from the Neg post nut to a body bolt that is nearby.
You can also run a double eyelet ended cable, from the engine block to a handy point, like a body bolt on the one I just mentioned on the body.
If you wanted to ground just the dash (IP), you would have to drop the panel under the steering wheel, it's easier to ground at a few points under the hood.
Cars loose grounding points, because of corrosion or rust, you are just rerouting the ground a different way.
You can also run a double eyelet ended cable, from the engine block to a handy point, like a body bolt on the one I just mentioned on the body.
If you wanted to ground just the dash (IP), you would have to drop the panel under the steering wheel, it's easier to ground at a few points under the hood.
Cars loose grounding points, because of corrosion or rust, you are just rerouting the ground a different way.
08-22-2022, 04:43 AM
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R170 99SLK230 + SLK32
many thnx.....
strange how it goes away after a few minutes.....
I've also started driving the car more than 5miles a week to get it worked out.....
I'm guessing the ABS comes on for a similar issue - it looses an earth and latches in fault....unlike the gauges which don't latch in fault and are able to come good.
s
strange how it goes away after a few minutes.....
I've also started driving the car more than 5miles a week to get it worked out.....
I'm guessing the ABS comes on for a similar issue - it looses an earth and latches in fault....unlike the gauges which don't latch in fault and are able to come good.
s
08-22-2022, 05:51 PM
#4
Junior Member
Grounds are funny like that, as they heat up from the poor connection, they start making a better connection.
You have a poor ground, somewhere, adding a ground strap might overcome that poor connection.
Finding that particular corroded grounding point may take ages, when adding a new source, only take minutes.
You have a poor ground, somewhere, adding a ground strap might overcome that poor connection.
Finding that particular corroded grounding point may take ages, when adding a new source, only take minutes.
