[T2] Fridge relay - ground starter Solenoid and ignition switch , how do they work together ?

[Christophe Guilbert]

Hi guy ,

I am adding a second battery and want to be sure that I understand 
correctly how works the fridge relay in the AUX battery compartment 
behind the driver seat. I need to fully understand this before adding my 
AUX batter (more about that later)

Please correct me if I am wrong but the fridge seems to be "double" 
controlled by terminal 85 and 86,
85 is energized by the ignition switch wire (blue) and 86 is energized 
by the ground starter solenoid wire (red/black)

How 87 and 85 trigger terminal works in tandem exactly ?

Here is my assumption:

85 and 86 seems to suggest that the relay is closed (selecting fridge 
over the LED panel) by a) after putting the key in , b) after engine 
started.  86 ( ground starter solenoid ) seem to do the trick by 
triggering the relay only AFTER the cranking phase (when the starter 
kick in) is completed so there's no damaging voltage peak to the fridge. 
Is that correct ?

So I guess 85 is energized +12V as soon as you put the key in and stays 
on while driving.
86 is more obscure to me , does it goes grounded AFTER the cranking 
phase (starter running) so 85 and 86 allowing the relay to close. If 
that so how is 86 state before the cranking phase , not grounded or +12V 
? if 86 is not grounded or +12V, than the relay stays open. After the 
cranking phase , 86 become grounded, 85 being already +12V, they close 
the relay and select the fridge.
Does it really work like that ?

Also my radio had this black/yellow strip wire which is energized and 
start the radio when I turn the key one crank .
What the difference between that wire and the 85 ignition switch wire (blue)

I am rebuilding my harness and all wires are out, this is very scary 
since I am so close from my trip to Alaska with the kids , I can't take 
a voltmeter and so any test to check how it works, so I really need the 
info.


Thanks


Chris