Battery Isolator Issues 1990 Suburban

[Bright Idea]

Recently installed a new Isolator and a second battery and now have an issue with no headlights, parking lights or interior lights with the key off.
The second battery is located in the back of the suburban and runs a 12 volt air compressor and a boat trailer winch. After this install, the headlights, parking lights, dash lights and interior lights only are on with the key on ? The isolator has a wire to the fuse panel to a circuit that is a key on circuit as was required by the isolator instructions. This problem did not exist prior to this install ? one other item that is possibly involved is the idle air control valve. The high idle has quit working at the same time as this was installed. I did try removing the key on wire at the fuse panel and the engine would not start. Searching for possible clues to what may be wrong with the isolator install to cause this, the second battery is receiving the same voltage as the main battery with the engine running. 13.9 to 14.2 volts

 

[SirRobyn0]

This is going to be a tough thing for anyone to help you with, without being there and seeing how it is installed. I think it would be helpful if you could give more info on the fuse it's connected to, the fuse# what it says for that location on the box and / or a picture. Pictures, or a diagram of the wires for the isolator, assuming you are thinking these problems were not there before the install. With question marks I'm think that your not sure.

All the isolators I've installed were for RV's but they all were pretty simple and had a charge wire attached directly to the alternator, is that the case here?

What about grounds, were any grounds for the vehicle changed or prehaps removed but not reconnected?

 

[Grit dog]

And if you unplug the trigger lead from the fuse box your lights work again with key off presumably?
But if you remove that tapped lead, then the engine won't crank?

Honestly, the cause of either of these problems is hard to relate to just tapping a power source off the fuse panel.
And yet the isolator latches and un latches exactly as it should....

Yup I'm of no help, sounds like @mtnmankev 's aliens paid you a visit...

 

[Bright Idea]

No, If I unplug the trigger lead, the lights still do not work without the key on but the engine has no spark. This is a new isolator purchased thru Waytek. I will go back thru the installation process. I did this 6 weeks ago and dont recall every detail. I do have another suburban with this same system that does not have this issue. I will look it over closely and see if there is any recognizable difference in the install. Ground configuration is a possibility.

 

[R Carnella]

Sounds like you should check for battery power at the headlight switch, if there's no battery power then check your fusible links and or connections at the starter.
Headlights draw power directly from the connection at the starter. If your Headlights turn on and off with the key.....someone screwed up pretty bad.

 

[Bright Idea]

I would agree, something is screwed up. This almost certainly has to do with the isolator install. As I said in original post, I have a second suburban with the same isolator. I will go thru its connections and see if there is something different than the configuration that I did using the instruction that were provided with the isolator or if I possibly missed something. I did this install, checked for charging at the second battery and left it for 6 weeks. Only when I came back to it in the dark did I notice that I had none of the lights that I listed in the original post with the key off.

 

[R Carnella]

I run duel batteries in parallel, just curious what isolator you're using?