1993 300E wiring harness?

[Stoney3]

My cruise and backup lights stopped working after installing a new neutral/saftey switch. Does this harness which connects to the switch have deterioration problem?

[WANT '71 280SEL]

You'll have tio get a volt meter to check that it's sending power, then that the lights are receiving power at there end.
Thanks
David

[stevebfl]

Other than being in the elements, I have never seen the deteriation problem so prevalent in the engine harness. It sounds like an adjustment issue on the lights, not sure if the cruise would have any relationship.

[Arthur Dalton]

Loosen the switch mounting bolts and Rotate the new switch
until you have back-up lamps in R.
The switch mount is elongated for this adjustment...

[Stoney3]

Thanks for your responses. When the tech put the switch on, it cranked in park and neutral. The backup lights did not flicker on when he went through all the gears. Could it still be an adjustment problem?

[Arthur Dalton]

If no lamps when he went through the gate positions, I would check the lamps/fuses themselves before anything else.....

[Arthur Dalton]

Originally posted by Arthur Dalton
If no lamps when he went through the gate positions, I would check the lamps/fuses themselves before anything else.....

I took a quick look at the schematic , and pin 1 and 2 are the R connection for both back-up lamps and signal line to EA [explaining the cruise possibility]...
so, first look will be fuse as cruise is on the live feed side of the R switch...

[Stoney3]

Thanks, he checked the fuses and the lamps which were working prior to the change. He thinks that the cruise is receiving a signal that the brakes are depressed, which would keep it from being activated. Only other thing he did was rease trans mounting bolts to get to the switch. He thinks that a ground was lost somewhere. Thanks

[Stoney3]

P. S. he hooked back the old switck and it stilled did not work, although he did not ground it to the car..

[Arthur Dalton]

That circuit is not ground dependant.
The switch itself may not be completely plugged in . There is a lock tab that has to be turned for a good connection when repalcing the switch. Just a possible.
There is a 4 prong connector around the gas pedal area with the circuit from the switch. If you either unplug this and see if you get an ohm reading [ continuity] from 1 and 2 when in R , this will tell if it is from the connector to the switch...or/if no meter, simply jumper 1 an 2 at the connector and BU lamps should light...if so, it is from the connector to the sw open circuit...if no lamps with jumper . it is from the switch back [ ie., power/lamps /wiring]

Could even be a bad switch...remember that the switch contacts are independant for BU and starter lock-out...so one can be OK with the other set not..[ 2 switches in one case]
Best bet is testing at the connector on driver side..

[Arthur Dalton]

Originally posted by Stoney3
P. S. he hooked back the old switck and it stilled did not work, although he did not ground it to the car..

OK
All the more reason to suspect power/fuse problem

The feed for that circuit [ circuit 15] is fuse #7 , 16A in fuse box..
Give that both a look and a slight twist..

[Stoney3]

Thanks,
Are pins 1&2 labeled at the petal area? I f you jumped then on the other side of the connection, should the BU work? You have been very helpful.

[Arthur Dalton]

Originally posted by Stoney3
Thanks,
Are pins 1&2 labeled at the petal area? I f you jumped then on the other side of the connection, should the BU work? You have been very helpful.

The pin # orientation should be on the connector case.
Looking at the CD , this connector [49/2] is located just above and to the right of the pedal, right of the steering coloum.
If you can not find pin #'s, use the below info to locate what you need...........

Pins 1 & 2 are Gry/Yl-Blk/Rd..
this will be back up switching.
2&4 will be V/Wt-V/Gn..this is starter lock-out.
These 4 will be the wire color codes for the proper 4 prong connector.
Continuity at the connector , on the side that goes through the floor to tranny for 1 & 2 should be found when shifter is in R..
...or, jumper 1-2 at the other half of connector [ live side ] and BU should come on..if not . problem is NOT in the switch part of circuit, as you are simply eliminating that funtion w/jumper...
Don't forget to have key ON when testing the live [lamp] side

[Stoney3]

Arthur
Rechecked fuses and lamps and they are ok. Have continuity on pins 1&2 at connecter 49 with lever in R. Problem must be further up the line. At some point someone replaced the stero an the antenna. As long as the switch is on the antenna stays up , evn if you turn off the radio. It does go down if you take the faceplate off the radio.

[Arthur Dalton]

OK
You have verified Sw OK..
Now go to the Blk/Red on the feed side of connector and look for 12v to ground. This is feed from fuse 7. If no reading , you have power problem. If power is there , then follow the gry/yl to connector 49/3. This is a single wire connector that goes to the EA module. It may be unplugged. The other gry/yl from the same connector goes to the lamp out indicator.
If both these check out , there is a break after the module , to the lamps.