Re : Wiring Harness

["jchapelhow" <chapelhow@xxxx>]

All.

Further tests/symptoms now as follows.

1. I have discvoered that my battery cutoff switch doesn't! With the 
switch attached to the +ve terminal and in the off postion (key 
removed) there is still 0.5v measured against the -ve terminal. Just 
to make sure I pulled all of the relays except the 
main/accessory/RPM. Fan fail and all others disconnected.

2. As stated before the binnacle has been removed. To this pile of 
removed bits I have added the panel that holds the indicator 
relay/windscreen wiper control/buzzer logic box. The plastic relay 
holder for the indicator relay had snapped where the screw holds it 
down. 

3. The large black cable which attaches to the panel described above 
appears on the wiring daigram to be a ground point, this makes some 
sense to me. If not the following 'problem' may be irrelevant!
With either engine block or the front wheel ground point as the 
reference point for my voltmeter, I get continuity signal to this 
black wire only if the battery is disconnected, when the battery is 
connected continuity is lost and a voltage difference of ~0.5v is 
detected.
I found that if I removed fuse 12 (courtesies/door lights) continuity 
was restored until the ignition swtich was turnedto P1 when 
continuity is lost again. Voltage was detectable ranging upto 0.7v.

4. As a second test the now freely dangling indicator relay unit was 
measured, the black ground point shows the same symptoms as above.

5. The LHS steering stalk control wires were disconnected. Now the 
main light swtich still worked but only alllowed side lights to be 
turned on, main beam was not selectable.


As stated previously in all modes the 'door lock' / Aircon 
illumination lights 'flash' with the indicators. I am assuming that 
if these are still misbehaving if I were to reinstall the binnalce 
the gauges would also still fluctuate. 


Suggestions?

John Chapelhow
DOC 19 : 'Boeing' 0737