240 General: wiper motor voodoo

[honestjoe]

Quick question..does the earthing foot to body on the wiper motor ever fail?..Rebuilt motor works a charm off the car but not on..unless i run a separate earth from the battery to motor casing..I guess there is a poor earth all around the car?..hj.

[Bob Meadows]

I think one of the main mounting bolts also act as the earth:~
Stand to be corrected on this- Just done a similar exercise on my car to see if an extra earth improved the wipers- direct to the battery (no difference) so the original must be ok.

A recent forum article has been completed on wiper motor refurbishing to include a better earth: it may be worth looking at the above and cleaning the connection up- you can quite easily add an earth wire to the motor body with a new connection into the bulkhead.
Bob.

[honestjoe]

You"re right Bob..one mounting bolt is the earth..top left methinks..no amount of sanding or shining helped..Left it for today to think...seperate earth may be the way forward..Thanks..hj...I might try a concave washer which covers the housing foot as well..hj

[Bob Meadows]

On the '88 240 you have an earth connection just behind the battery, blue lead into the bodywork:~
This should give a strong earth link to the wiper motor if you don't mind an extra wire.
One of the cable fastener bolts could be another option and slightly closer for a cable run.
Hope it helps.
Bob.

[honestjoe]

Morning..To the best of my knowledge today!..None of those wiper to body bolts earth the motor.The eyelets through the feet fit either side and the rubber grommets isolate the eyelets from the housing..Soooo..I"m moving to the connector block as a source of earthing..Removed gearbox top to check copper strip which sits proud of cover..All else fails i will reroute a new earth..I just want to make sure i"m not being an egit!..hj.

[honestjoe]

It"s official..I am an egit!...lower right bolt has a small brass plate that earths the casing to the eyelet..I thought the plate was something i did when i getting desperate!..its located by two almost insignificant nipples on the casing.just make sure the two eyelet halves are clean and can connect together when bolted home..When i came to take the motor off yesterday the brass plate was out of position which made me think even more it was something i had a hand in..anyway works now..just have to put the wiper rack back on..easy?..hj.