Reversing light switch
Discussion
Before I start pulling things apart I need a little information. The reversing light on my 3R had stopped working and it seems to be the switch on the gearbox. (With the ignition on and the car in reverse gear there is no voltage on the black/white wire pin in the rear harness socket). The switch seems to have what looks like a moulded plastic plug on the top but it looks like this is a permanent fit as there are also some spade connectors under some heat shrink close to it. Is this the case? I don`t want to apply too much force to anything or start cutting up heat shrink until I know what`s what! I seem to recall that the switch assembly is a Noble bodge of a Ford part.....Thanks guys.
With the ignition on, jump together the two wires that go to the backup light switch and see if your reverse lights go on. If they do, then the problem is the switch or the lousy connection to the switch. If they don't, then the problem is elsewhere - I'd probably start with the connector to the rear clam harness.
Thanks for your help guys. My car has LED `afterburner` rear lights so I didn`t think it would be a problem at that location. I checked both halves of the rear connector - no pins had `backed out` and the female side looked pristine as well. There was no voltage on the main harness pin for the reversing lights - with the car in gear and the gearbox in reverse. I`ve now done wht Jim suggested and made up a jumper lead and shorted out the wires bypassing the switch - and the light comes on. Putting a multi-meter across the switch it`s open circuit with reverse seleceted, so the problem is either the switch or the wires/connectors onto it. I`ll explore further but I can see I might need to go the new switch and connector route.
Sorry about the typos in the last response. I`ve now got the switch out - what a bodge.... For those of you who haven`t had to look at the part - yet - there is a plastic female connector on the top of the switch with two fragile male connector pins. Noble have fixed some small spade connectors which attach over these pins to two short lengths of wire which have bullet connectors that link into the main loom. They have then filled the female connector with what looks likes silicon bath sealant. Just a slight problem with this design solution - the sealant just forms a path way for moisture to go down around the fragile pins and corrode then whilst at the same time not providing any support to them...
One of the pins on my switch had almost corroded right through and had then snapped off - and the other didn`t look much better. I`ve now got a new switch from the local main dealer - in stock and £21.47 with VAT. Unfortunately you can only buy the correct connector as part of the Mondeo loom which is isn`t a viable solution so I`ve now contacted Rossion in the US....
The saga continues.
One of the pins on my switch had almost corroded right through and had then snapped off - and the other didn`t look much better. I`ve now got a new switch from the local main dealer - in stock and £21.47 with VAT. Unfortunately you can only buy the correct connector as part of the Mondeo loom which is isn`t a viable solution so I`ve now contacted Rossion in the US....
The saga continues.
If you can't get the proper connector, another option is to carefully solder leads onto the pins on the backup light switch, then pot the whole mess with epoxy. That should make a watertight, weatherproof seal. On the other end of the leads, put a weatherproof connector like a Weatherpack or Deutsch connector, and replace the spade ends on the wiring harness with the mating side of the weatherproof connector.
In general, epoxy resins are non-conductive and make good electrical insulators. The brand I use the most (JB-Weld) even states in the instructions that it can be used as electrical insulation. Back in a former lifetime, we used to encapsulate circuit boards in epoxy for vibration resistance, and to keep prying eyes from copying circuit designs.
However, the amount of conductivity is one property that can be modified by adding stuff to the resin - for instance, you can get silver-filled electrically conductive epoxy which is used to make electrical connections where you can't solder. So, your best bet is to check the manufacturer's literature...
However, the amount of conductivity is one property that can be modified by adding stuff to the resin - for instance, you can get silver-filled electrically conductive epoxy which is used to make electrical connections where you can't solder. So, your best bet is to check the manufacturer's literature...
I did think of potting the connector as suggested, but I could forsee a couple of potential problems. Firstly the new switch does not appear to be totally sealed - there is an aperture in the centre between the two pins and this would need to be sealed before potting. Secondly I was worried that in the long term the epoxy might shrink away from the pins creating a path for moisture to get in just like the previous problem. For that reason I`ve decided to go the proper connector route - not cheap at $15 for the connector plus $10 packing/shipping costs from Rossion but hopefully that will be the last time I have to do the repair job...
Everything now works! I got the new connector from Rossion which comes with about 6 inches of cables attached - fitted new `bullet` connectors - connected up to the new switch and the reversing light now works. I can`t imagine why Noble didn`t use the correct part in the first place - if you could buy new engines and transmissions from Ford why not a simple plug/connector....
ikaruseco said:
Hoping someone can help. I am having problems with my reversing lights, the switch has gone. How do you get to the switch?
The switch is on top of the gearbox on the passenger/lefthand side of the car. If you go to the coolant expansion /header tank then look under the area nearest the centre line of the car down on the gearbox you will see two wires going to the switch. The latter is screwed into the top of the gearbox.Gassing Station | Noble | Top of Page | What's New | My Stuff