code alarm trunk trigger

When I probe the trunk release trigger wire with my MM, it jumps to +3.5v when the  the trunk button on the fob is depressed. 

I understand this is supposed to go to ground when the trunk button is pressed.   

What gives?   I can't get this to trigger my hatch release on my 1994 K1500 Blazer.

My truck needs +12 to pop the hatch, so I wired in a relay as follows -

85, 87 - +12 Constant

86 - Trigger from Code Alarm Brain

30 - To the hatch release switch

But, I get nothing.   Something seems to be up with that trigger wire, no?  

Ok, a little further investigation.  While connected on my bench - the trigger wire on the alarm shows +12v when the button on the fob isn't depressed, when I depress it, it drops to 8.5v

Apparently this isn't enough to trip my relay?

More info -  this is an OLD SCHOOL but NIB F55 Code Alarm.  I figure for a 1994 truck, it's more than enough.

Anyway, the unit has fuses as follows... the grayed out areas are missing fuse connections..  like, there's nothing on the PCB to insert a fuse into.  Just blank. 

[IMG]https://i55.tinypic.com/29crkg0.jpg[/IMG]

I even tried jumping the solder connections on  the "blank" pcb for (+) and (-) trigger but the output never changed.

Does this mean my brain isn't even programmed for  trunk output?

Convert a Negative Output to a Positive Output

If you have a switch or an alarm or keyless entry that has a negative output that you wish to use to switch a device that requires 12V+ such as a horn, dome light, parking lights, head lights, hatch release, etc., wire a relay as shown below to convert the negative output (trigger) to a positive output. Here's the same configuration showing a negative output from an alarm or remote keyless entry used to activate a trunk release solenoid that requires 12V+ to release the trunk.

Does the unit have another Aux. output...If so...Try using that one and see what happens...!? You're sure you have the correct rear hatch release wire...? I just perused the install guide and it looks like that is the only output...If you are certain you have the correct wire for the rear hatch...You could apply 12v to the rear hatch release wire and see if it pop's...This wire should show 12v when button is pressed...!

Yes, i've wired my relay exactly like that.  Confirmed that it works by attaching 85 directly to ground.  Hatch pops.  However when I connect wire 16 shown here, it does nothing. 

https://www.the12volt.com/installbay/file.asp?ID=664