The idiot light cluster that I have is acting strange in my 86 NA and I was wondering if the behaviour it is exhibiting is normal or not.

When the key is turned to ON, all of the lights on the cluster do not light up and only the ones that would otherwise be on when the engine is running such as the Door and Brake light are lit up, however after about thirty seconds, the rest of the lights light up and they stay on afterwards. The strange part is that this is completely intermittent and there are times where all of the lights will light up as soon as the key is turned to ON, and times when they will exhibit the above behaviour. I have connected a jumper wire to the White/Black alternator cable and confirmed that the CPU relay does click so that side is working and I have resoldered all of the connector joints on the idiot light cluster and confirmed continuity.

What could be causing this time difference between the time that I turn the key ON and the time the cluster lights up fully and is it normal to have to wait a little bit. The CPU alternator relay does click in all scenarios.

 

The most common cause for this is cold solder joints. They tend to affect the body CPU, logicon, and clock/idiot lights. The ECU is rarely affected, thankfully.

If you remove the idiot light cluster and expose the solder joints, you can reflow them. I like to add a bit of fresh solder when doing so (not too much though, or else it gets sloppy). This will fix the problem most of the time.

Some of the idiot lights are driven through the CPU (seat belts, stop lamp) so if this doesn't fix the issue then resoldering the CPU is the next step.

EDIT: Sorry, I missed the part where you said you resoldered it already. If you didn't also resolder the CPU then that's a good idea

 

I tackled the CPU today and I found that someone had already been in there and already touched up the solder joints on the connector; however, very poorly... What the previous owner did was simply pile solder onto the existing joint, this made for a huge messy joint and what I did instead was get rid of the previous solder that was on the connector, cleaned it up, and then applied new solder and so far, there is no more erratic behaviour. Thank you @WondrousBread