I installed an auxilliary fuse block into the wife's '12 JKUR and lately, it doesn't seem to be operating as it did when it was first installed. Lately when we get into the Jeep and start it the lights and/or seat heaters won't operate immediately. It is almost like the relay needs to heat up or the battery needs to charge for a few minutes before it will provide enough power through the new fuse block setup to work. Is that a realistic explanation or is there something else such as my wire size or something else I haven't calculated. I'm 100% positive I'm under 30 amps of draw when everything is being used simultaneously so that can't be an issue...or can it?

Items used:
6 circuit Blue Sea block with neg bus bar good for 100A of draw
80A circiut breaker
100A battery disconnect/solenoid/relay (whatever you want to call it, I've seen all three)
#8 wire for main power from battery to the circuit breaker to the relay to the block. All connections are crimped, soldered and heat shrinked
#12 wire for the accessory power wire to fire up the relay to power the block.

The accessories hooked up are:
2 Rigid Duallys (probably less than 5A draw)
One 10" LED bar (3A draw)
two rear seat heaters (each one on high only pulls 5 amps)

Since my accessories aren't that powerful, I can't imagine its the battery because as soon as the Jeep is started, it's charging so I should have full power from the battery. The 80A circuit breaker is not a high dollar one but it effectively and positively acts as it should, resets as it should (using the test button). That leaves my big relay. I'm no electrician so I have no idea what's inside of one of them so is it possible that it needs to have power flowing through it for a short amount of time before it will allow full power to flow? If so, is this common or is my relay just a POS and need to be replaced? I'm down on the Gulf Coast so it doesn't get that cold at night, usually around low 40's, sometimes lately, in the mid 20's and when it's warm out, it seems to be fine.

Any assistance or ideas would be great...

 

Not exactly sure how you have the relays wired up or what powers up the relay coil to pull in the relay, but if you are using power from the CANBUS system the relay will chatter due to the voltage pulsing instead of being constant.
You can verifiy this using an analog volt ohm meter and measure the actuating voltage for the relay.... The needle will fluctuate indicating modulating voltage instead of indicating constant 12VDC.
You would need to install a capacitor inline for the positive activation source to ensure the relay stays energized.

 

I am trying to understand your setup fully. I read and reread it and believe you are getting a delay in only ALL of the accessories that are connected to the 100 amp disconnect, relay or whatever it is. IF that is true you can try 2 things. 1. Replace it. Or 2. Jump it out with a heavy gauge wire to see if the delay is still happening. One question, once it finally works and you turn the Jeep off, will it delay again when you re-start? Can you better describe the 100 amp thing?

 

Here's pics of my wiring diagram and the items I used...

I am pulling the 12V from an open fuse slot in the factory fuse block with a Add-a-circuit so I'm not sure that is what you mean by the canbus system. As far as turning the jeep off and then back on goes, there is no delay.

 

There are 2 kinds of high current solenoids/relays available. One is an intermittent on and the others are continuous on. You might be getting coil burnout on an intermittent one when you are looking for continuous on rating and this means it would eventually just not work. This is to do with the relay coil not the ability for the relay to conduct a high current draw through it. Put a voltmeter on it and see if there is a delay and note when it actually comes on as it may take the higher voltage from the battery recovery charge after start to actually pull it in due to the coil failing. Failing this it could just be a loose connection.

 

My thoughts exactly, you ether have a intermittent solenoid or check the ground from the solenoid to the body. My first thought is you have the wrong solenoid, something like this is what you would need. https://www.amazon.com/Rareelectrica...s%2C106&sr=8-8