Starter relay / ignition switch New battery and new starter , sometimes won't start , will start after I play with the wire that goe's to the fuse box inside the hood . Could it be a maxi fuse ?

I'm assuming just by the fact you had a new battery and new starter that sometimes when you turn the key to the start position , nothing happens . Is your vehicle a automatic transmission ? When it doesn't start have checked for battery voltage at the starter solenoid S terminal ? Is there B+ voltage at pins 30 & 86 for the starter relay ? Pin 86 while cranking the engine or trying to crank the engine over . Pin 30 check with key on . Try moving gear selector to neutral . Videos on youtube for basic automotive electrical testing . How to voltage drop test starter motor circuit Find a wiring diagram at www.bbbind.com
Starting System Circuit Description
Voltage is applied at all times to the ignition switch from the IGN A fuse 6 through CKT 242 (RED). When the ignition switch is turned to the START position, voltage is applied to the CRANK fuse 8 through CKT 5 (YEL). From the CRANK fuse 8, voltage is either applied to the clutch pedal position switch (M/T) or the transmission range switch (A/T) through CKT 806 (PPL). When either the clutch is disengaged (M/T) or the transmission is in park or neutral (A/T), voltage is applied to the coil of the starter relay through CKT 1035 (PPL/WHT). Since the starter relay is permanently grounded at ground G105 through CKT 150 (BLK), the starter relay energizes.
Voltage is applied at all times to the starter relay contacts from IGN A fuse 6 through CKT 242 (RED). When the starter relay energizes, the starter relay contacts close, and voltage is applied to the starter motor solenoid. Since the starter motor solenoid is permanently case grounded, the starter motor solenoid will energize two coils. The pull-in winding coil energizes in order to pull the starter motor solenoid contacts closed. When the contacts close, a plunger on the contacts causes the pull-in winding coil circuit to open. The hold-in winding coil then holds the starter motor solenoid contacts closed. Voltage is then applied to the starter motor from the battery through CKT 1 (BLK) and the closed contacts of the starter motor solenoid. Since the starter motor is also permanently case grounded, the starter motor will run until the ignition switch is moved out of the START position. When this happens, a spring in the starter motor solenoid moves the starter motor solenoid contacts and the plunger back to the rest position.

There should be power o the small terminal of the stater anytime the key is in the crank position. I would start with checking that. If there is no power you will need to trace that circuit back.

That wire gets power from the starter relay and the relay gets power from fuse 20 in the TIPM (underhood fuse box). The starter relay control side starts at the ignition switch. The pink with dark green wire should have power with the key in the crank position. That power goes to fuse #10 in the TIPM. it then goes to the starter relay. the starter relay is grounded by the PCM.

Give that a whirl.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Before you do any thing check for loose or bad connections. Also check you ground connection to engine. Check Fuses, relay and for a Fusible Link open circuit. Now let me explain what a Fusible Link does. They are short lengths of small gauge wire installed between the Battery and the Ignition Switch, or the Battery and the Fuse Panel. They'll melt and open the circuit before damage occurs in the rest of the circuit. I hope this was helpful you.

I will try to help, powell. Your start circuit from battery to ignition switch to starter-and back to battery. You may need to check every thing here, including the grounds, for a loose connection, or just possibly a failing part.
If only complaint is intermittent starter action, and no other problems with ignition switch, let's assume switch is good, so battery to ignition switch is good. Now from the switch, a yellow start wire goes to the instrument panel fuse block, to "crank" fuse #8 (10 amp), from there a purple wire goes to the safety switch. If manual it is a clutch pedal position switch (simple on/off switch-when clutch down switch is on). If automatic, purple wire goes to Transmission Range Switch on the transm.-in park or neutral the purple wire has continuity in and out of switch.
From that switch, the purple wire goes to the starter relay (under hood fuse-relay center). Now the relay: purple wire in start will energize the relay- wire goes to coil side of relay, and then coil side goes to ground. On relay power side, the power feed is a red wire-and it is the same red wire that initially sends power to the ignition switch. A 40 amp fuse in fuse-relay center sends power to ignition switch, and a splice goes to the starter relay as the power feed for relay. When relay is energized, contacts close, and power is sent from relay to the starter solenoid, again on a purple wire. When solenoid contacts close, starter motor is connected to the big battery cable on the starter.

There is your start circuit. try a new or different relay, try a new or test the clutch switch (or transm. range switch). Buy a $5 test light and use it to check where power is lost when starter won't operate. Hold key in start and check if fuse #8 is getting power. Check the safety switch, with key held in start, the purple wire should be hot. Check if relay has a power feed (pull relay out and check terminals) and if relay coil has a power signal in start. Check the relay's coil side ground. If that ground is intermittent, relay won't work.
When it won't start, use a test light, you should be able to find it.
Good luck.

Check battery must fully charged, check starter fuse and relay Check 12 volt wire from ignition switch to starter relay in the fuse box ,then check 12 volt wire from starter relay to starter motor solenoid if if it's everything is ok then change the starter.

So it's a no crank condition? Do dash lights, gauges, and everything else work when the car won't crank over? If so, buy a cheap $5.00 testlight, and when the car won't crank, pull the small black wire off the starter solenoid. While someone holds the key in start (cranking) position and clutch pedal depressed, see if the black wire has power as it should. (Ground the testlight and just touch the wire's end terminal. If powered, the testlight will light up.) If power there, then the starter solenoid is failing. Toyota starters are very good units, but the solenoid's internal contacts get old and pitted.
If no power at the black wire, then the start circuit from ignition switch to clutch safety switch (on the clutch pedal) to starter relay to starter solenoid will have to be diagnosed. To double-check: take a single battery jumper cable and put it on the positive battery post connection. Put the other end of the jumper cable on the solenoid terminal where black wire was removed. Key can be off. Make sure car is in neutral, brake set. If starter now operates, solenoid is O.K., and it is a problem in the start circuit, -ignition switch, neutral start switch, or in the wiring.
Now find a grounding place for testlight under the dash. When car won't crank, check for power coming out of ignition switch on the black wire with white stripe. This is the start wire for the starter solenoid. Key must be in crank position. Wire shoud be powered-ignition switch is working. If no power, switch is failing. You can do the same for the clutch start switch-it's a simple switch, that when clutch is depressed switch is closed and passes power on from ignition switch to the starter relay (thus allowing power to the starter solenoid). Black wire, red stripe-this is wire from clutch switch to starter relay. When key is in crank, clutch depressed, this wire should be hot.
With me so far? Still haven't found a problem, or any loose connections? Next and last is the starter relay. It is located under dash, close to gas pedal, but under the center console, just forward and left of gear shifter. It can be tested and the wiring diagnosed there, but relays are cheap, so just swap in another and see if that helps.
If you have tried everything, and still no help, you could try a new wire from the relay to the starter solenoid. This is that black wire we started with. Older toyotas sometimes have a problem with degraded wiring not passing enough current to operate the starter

it has a good chance to being the starter relay but it also may be a break in the power line to the starter or the solenoid on the side of the starter if you replaced the starter only or not or a dead battery or check your fuses to you ignition and your relays aswell there are many possibilities that could come in to play just do a elimination start from the starter itself and check everything that in between til you get ot the battery and if witch should be depending on what kind of vehicle you have starter solenoid ground wire and positive wire going to starter relay aswell as other wires tying in to go to the positioning ignition switch that could be the problem to, it's commonly mounted down but your foot pedals on the top of the steering column and check your fuses hopefully you could try these or use any of this imformation to help you with your problem well good luck..

Is the ignition switch good? If the starter/solenoid; starter relay, battery and cables are all good that is about the only thing left.

Do you hear a click when you turn the switch?

Check properly the ignition cable that goes the the starter solenoid. Is there power on that big cable on the starter? Try to bridge with the ignition cable there. It should crank.

when looking at it from the front the most left is from the battery, now going right from there the little pin is from ignition, basically to flip this giant switch on. next little pin goes to your fuel shut off relay, it will turn on that relay to send power to your pump while cranking, next is the large out. far right. that goes to your starter.