75 240D W115 won't start glow plug or electrical?

My 75 240D has developed a weird problem.
When I turn my key into the on position, my instrument cluster comes to life, showing battery indicator light on, fuel gauge etc. When I
put a load on the electrical system it just dies.
I.E. I depress the brake, turn on the lights or pull the starter into the detente position to activate the glows plugs, my instrument cluster shuts off and nothing happens. If I return the key to the off position and then back to on the dash comes right back to life but repeats when I try to start it normally.
I put the Battery on a voltmeter and it tests at 12.65v (resting since I can't start it).
Just prior to this the car was having difficulty starting, I was starting to think that the GP's were malfunctioning so I tested the connections at the relay box on the firewall right after the battery.
Placing the positive end on the relay box and negative end on the battery terminal I got 83 ohms resistance from plug 1 and off the chart on the rest.
It looks like my car some time in the past (before I owned it ) had it's series wired GP's replaced with what looks like parallel wired GP's with a ground strap at front (last/first closest to radiator) cylinder lifted. Is this correct? I haven't taken any GP's out to examine them to see if they pencil style or loops yet. Also 240D's don't have the same GP relay system as a 300D right?
Is there a fuse in the GP system that would cause this behavior and prevent the starter from turning over or should I looks elsewhere and if so where? My old Chilton's/Pirated Polish website wiring diagrams are hard to understand. I also am having trouble figure out where these things are located as most docs are for W123 cars.
I have pics of my engine compartment that show the ground strap lift. There is also a thing that looks like a GP in between Glowplug 1 and 3 what is that? There is a wire that runs from that piece which is broken, could that be significant? I have pics of that too
My Ohmmeter and Flashlight await......
thanks, je
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Your battery needs to be replaced.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I would check the connections on the battery and the cables. The condition you describe can be caused by a loose connection, OK on minor loads but failing on high amp draws.
--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I would have to say replace your battery ground cable first... it is the easiest cable to do so.
As for your glow plug. test them with ohmmeter directly at the glow plugs... one to GP terminal and one to the engine block.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.