Ok spent more time last night and took a picture of one of the solenoids. This one is on the port side of the engine. After some testing it appears as though both solenoids do not work.
The one on the starboard side I think is supposed to be part of the glow plug
circuit. It has 4 connections on it. Two are big poles and two small male spade connections. The two big poles look like one is connected to the battery
+ via the alternator output post. The other big pole goes to the wire connected to all the glow plugs. Then the two smaller spade terminals, one is a ground goes into the wire harness, the other is hot (12v+) when the glow plug position on the ignition switch is selected. I believe what is supposed to happen is that when the glow plug position on the key switch is hit 12v+ goes to this solenoid which then connects the two big poles together (like a relay) allowing high amperage current
to flow from the battery
+ to the glow plugs. The glow plugs themselves get their ground by being threaded into the head
. Problem is when the solenoid is activated it does not make this connection. The other big post going to the glow plugs never gets 12v+. Bad solenoid? Replace with a relay? What sort of amperage will the glowplugs need, (#8 wire feeding them). Am I way off on how this glowplug circuit should function?
Now the solenoid on the port side is a real mystery. Its the one in the photo
and is identical to the one on the strbd side. Same 4 connections but heres where it gets weird. The two big poles on this solenoid are both connected to #8 wires one (Black and closest in photo) goes to a mounting bolt of the starter (ground) the other (red in photo)to a bolt on the starter case where other grounds are attached (also a ground). The two small spade terminals one is part of the wire harness (painted blue on right side of phots) and is a ground the other leaves the solenoid (tan in photo) and is then split into two wires. One of these has a diode soldered inline and continues to a brown with red strip that gets 12v+ when the glow plug is slected. The diode will only allow current
to go from the solenoid side to towards the key switch(glowplug setting). It will not allow current to go from the key switch(glow plug setting) to this solenoid. The other half of the wire where it is split goes to the a sending unit looking device which is the engine stop and has something heatshrunk inline with it as well, possibly another diode?
There is a second kill switch for the engine mounted just to the left of this solenoid you will see the button in the photo
. When this button is pushed 12v+ goes to the sender and shts down the motor
. It also flows to this wire with the diode and I guess heads back up to the ignition switch ( Glowplug setting). The kill switch sender (stop solenoid?) has 3 small red wires coming off it. One goes to the kill switch at the engine instrument panel and supplies 12v+ when activated. The other goes to the kill swithc in the photo and does the same when pushed. And the third tees into the tan wire with the diode.
I have no idea what the purpose of the diode(s) could be. No idea what this solenoid is supposed to do. Given that both big posts on it are connected to ground what could it possibly be controlling?
To make matters worse there appear to be two starter solenoids as well. One on the starter itself the other on the bulkhead near the starter and connected to the one on the starter. My only guess is that maybe the solenoid on the starter itself failed and this remote
one is somehow serving in its place? But that does not really make sense and I have not yet had a chance trace out all the wires coming off this solenoid.
And lastly up behind the engine instrument panel are 2 small relays not sure what they are for either...