radio delay off using 528t

I have installed an aftermarket radio in my car, and when I switch from ACC to START/ON, the radio will reboot, the same goes for my factory radio. I'm guessing ACC drops out during engine crank. I heard I could use the 528T to prevent this, but am completely lost on how to connect it. Any suggestions on what colour wires to connect to what? My radio wiring has a +12v constant (to save settings), GND, and a +12v that is switched.

Look at this logically. The ACC wire of your deck (both factory AND aftermarket) is designed with intent to deal with that fact that it cuts out power during crank as well as when the ignition switch is off. So with that in mind...there is a problem with both your factory and aftermarket deck...or...you need to look elsewhere. A 528T is just a pulse timer...it can not solve the problem you are having. Now if you want a bandaid you could do this. Use 2 1-3 amp diodes (The acc wire draws almost nothing) and set it up like this.. One diode anode (stripe side) to the crank wire...the other diode anode (stripe side) to the ACC wire. Join the cathode sides (non striped) together to the ACC wire of your deck. What this will do is keep power to the decks ACC wire during the crank cycle. With that said I still would be curious what else could be causing this. I would suspect you are also encoutering a constant voltage drop or loss on the decks constant wire during crank which would most logically explain this problem. I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.

Go to Radio Shack and purchase (2) 3 amp diodes and a 470 microfarad 25 or 35 volt capacitor and I will tell you what to do with them tomorrow.

Without knowing what kind of vehicle you have, DO NOT connect the 2 diodes from the ACC to Start wires.

I agree and it was an oversight. You do NOT need any caps for this but we should know the vehicle. Not all vehicles use 12vDC for ACC. To the OP: if you have any fear using diodes and have not already confirmed you have an amp or so of 12vdc current from you acc wire I can give you a safer diagram using a realy to isolate.I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.

And...with that said it STILL does not explain why your factory of aftermarket deck losing 12v during crank should require a reset of anything, And that is what I personally would be more interested in figuring out rather then bypassing issues with diodes, caps or relays. There has to be a simple reason for this that can be rectified without band aids.I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.

I'd suggest 2 diodes similar to above but from IGN and ACC +12V with their lines towards 86 of a relay (85 to GND). Relay 30 can be straight from the battery (thru a fuse; probably 10A) with 87 to the radio (ACC) power. (But break the original ACC power wire to the radio to prevent this circuit powering other "cranking off" ACC loads. That could be done by removing the radio's ACC fuse if it is a dedicated circuit.)

Why would he need both acc and ign? Ignition should not be losing 12v during crank. The issue he is having is the deck requiring a reset after crank. Granted we are basing all info off assumptions because we do not have voltage readings of ign during crank but can assume the deck is hooked up to the acc wire. Now as well we know some newer vehicles do not even have a "true" acc wire but could be using data/ mulipex heck could even be a low current/votlage - at the ignition harness. Now it might seem I am over complecating it but the root of the problem is actually elementery. The deck is needing a reset during crank (the OP claims both the factory AND the aftermarket deck have the same issue)...so using the info we are given would you not want to determine what is actually causing both decks to lose memory during crank?I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.

Well... ACC loses +12V during cranking. IGN does not lose +12V during cranking. Hence logically OR both and you have cranking +12V ride thru. To OR ACC & crank/STart risks 2 breaks during the transition. If it's a voltage drop issue, the unit will still reset and then a cap else dc-dc converter will be required. If it's the loss off ACC power (as it seems to be - ie, it is powered by the ACC supply isn't it?), then 2 diodes solve it. And adding the relay means (1) low power diodes (1N400x etc) and (2) no diode voltage drops with option of a direct clean +12V battery source. PS - I am assuming the radio is still desired on ACC, hence both ACC & IGN. If not, just move its power from ACC to IGN.

But this does not adress the problem. If the problem with both the factory deck and the aftermarket deck was they did not like a spike or drop during crank then you could use diodes and/or a relay to help this. But would the factory install a deck that would require a reset everytime you lose acc power during crank? Would an aftermarket design a deck that would require a reset every time the acc wire loses voltage during crank? Do you see where I am going with this? I can assume like myself you have been doing this for so freaking long you think you have seen it all...but realize there is something new to learn every day. Perhaps I am missing something. How could the ACC wire losing power during crank cause both a factory deck AND an aftermarket deck to require a reset after crank? This is my issue here. I think looking at the ACC wire is not the best first place to start in this situation. Granted many of us could come up with countless ways to retain acc power during crank it still makes no sense.I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.