No power at starter or relay - 1992 Buick Riviera

It's in the power distribution center. You're barking up the wrong tree. If the engine cranks, the starter relay is good. The relay just sends power down to the starter pull-in/hold-in solenoid. If the relay wasn't working, the starter would never even turn

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.

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No. Your problem most likely is the starter relay.
Let's try this again r you getting power to the relay if not could be ignition switch if power is present at relay but not at starter break in wire

Let's see if I can explain it. Pretty simple start circuit, but starting issues are very common to Hondas and Toyotas of the '80's and early'90's. Lots of guys used to rewire their start circuits with new wiring and relays from ignition switch to the starter solenoid just to stop those no starts.
From the ignition switch is the black/white start wire, it is hot only in start, goes direct to the "starter cut relay"- a 4 pole starter relay, the black/ white wire (black with a white stripe) is both the power feed and the coil power to the relay. Before the wire enters the relay it is spliced. one wire goes to power feed at relay, other wire goes to coil side of relay. Here's where the clutch switch comes in: the clutch switch acts as the ground for the relay's coil side. Okay, you turn key to start, power goes to the relay on both the power side and the coil side. When clutch is depressed, it grounds the coil side of relay, this energizes the relay, so power goes out of relay on the power side, as a black/red wire...and goes direct to the starter solenoid. Somewhere before it reaches the solenoid, it turns back into a black/white wire. But nothing else is in a wiring diagram for your start circuit. Buy a can of CRC electronic cleaner. Spray all connectors in the start circuit. Pull off the solenoid wire at starter-that connector. Also the starter relay , pull it out and clean the relay terminals where it plugs in. Get all clean connections in the circuit. If no help, swap in a different relay. If still no help, get a voltmeter (or a test light), when the starter doesn't want to work, check for power at the starter solenoid with key held in start, and clutch depressed. If power there, the solenoid is the problem. If no power, work back to the relay. Pull relay out. With key held in start, two terminals for the relay should have power-the coil plus side, and the power feed from the ignition switch. If both have power, may be the clutch switch not grounding the relays coil side. If no power to relay, check the start wire out of the ignition switch.
Need a wiring diagram? This site is awesome-free wir. diagrams and TSB's for every make and model:

If by lights, you mean the dash lights come on, then ignition switch must be getting power. If dash is not working with key on, check the 30 amp fuse link which powers the ignition switch.
If switch is good and starter is good, the start wire from switch goes to, if automatic, to inhibitor relay (the park/neutral function) and then to starter. There is also an inhibitor switch on the shifter or on the transaxle that turns on the inhibitor relay when key is on and shifter in park or neutral. The inhibitor switch is powered by a 10 amp fuse D.
If you have a manual transmission, the start wire from ignition switch goes to the clutch interlock relay and then to the starter. This relay is turned on by the clutch interlock switch on the clutch pedal.
You can check for power on either relay, the inhibitor relay or the clutch interlock relay, with a test light. Pull the relay out, have the key held in start position. Now both relays would have power showing on two terminals where the relay plugs in. If inhibitor relay only has power on one terminal or no power at all, either ignition switch is not sending power or fuse D is out or the inhibitor switch is not working right. If clutch interlock switch does not have power on two terminals either the ignition switch is not sending power or the clutch interlock switch is bad.
If the relay checks are good, check for power on the small wire to starter with key held in start. If you have power there, the starter solenoid must be out.

I'm back, Gary-like that commercial on tv where mechanics chase cars down the road on creepers! You have a failing connection somewhere. If you rock it and it works, don't sound like a relay-don't sound like the neutral safety switch-it really sounds like a failing starter or starter solenoid. To check, wait till it won't start, then check for power at solenoid wire when key is held in crank. If power then, suspect a bad starter or solenoid-have tested. If no power, try a new relay-starter relay. Another relay in your car may be same as the starter relay (same part number) so try swapping a different relay. Again, doesn't sound like relay, but you never know until tested. Good luck.

Did you check for power at the starter ignition terminal? It is the small YELLOW/BLACK wire on the starter. If there is power there, replace the starter. If there is no power there, you should check your starter relay an its associated fuses.
The relay primary side is protected by fuse number F2.31 (15 Amp) in the Central Junction Box. This fuse provides power to the clutch safety switch on the WHITE/PINK wire. Then the power leaves the clutch safety switch on the TAN/RED wire and goes to pin 86 on the relay.

The relay secondary side is protected by fuse number F2.113 (30 Amp) in the Central Junction Box. It provides power at pin 30 on the relay, which is also located in the Central Junction Box.

Pin 87 at the relay is the YELLOW/BLACK wire metioned earlier and goes to the starter motor.
Pin 85 at the relay is the primary GROUND. This should be ground at all times.

The ENTIRE starting system can be checked/diagnosed from the pins at the starter relay if you use the correct methods and equipment.

Hello, You need to check the Starter Relay. The Starter Relay connects the Battery to the Starter when you turn the Key to Start. There are 1 or 2 small wires that connect on the Starter Relay.

The idea is the Key sends power to the small wire to make the Starter Relay work. You need to test the Starter Relay. Have your car in Neutral and out of gear. You can use a jumper cable and bypass the Starter Relay by connecting one end of the Single jumper cable to the terminal connector from the Battery where it mounts on the Starter Relay. The other end will be live, hot, and full of power so watch where you lay it.

Then there will be sparks when you touch the end of the jumper cable to the mounting connector coming from the Starter where it bolts onto the Starter Relay. The Starter should crank. This will mean the new Starter is good. You can use any metal tool to bypass the Starter Relay if you do not have a jumper cable. Be Careful, the tool can melt and burn you.

One final test is needed. The small wires I mentioned earlier are important to making the Starter Relay work. You need to see if the small wire is getting power when the Ignition Key is turned to Start. You need a test light or Voltmeter to show if the small wire is providing power. If the small wire is providing power, then you need to replace the Starter Relay and you are good to go.

If you are not getting power through the small wire, then you must trace down the problem. There is a Safety switch on the clutch linkage or Brake linkage which must be pressed before it lets the Starter work. This is called an Interlock switch. There can also be a safety switch in the shift linkage which must be in Neutral before allowing the Starter to work. These get power from the Ignition switch which may also be bad.

You most likely fixed the problem just by replacing the Starter Relay. If you do not want to test, just buy a Starter Relay. I gave you extra information for bad switches and how to pinpoint the problem and this time you might not need to know this stuff.

I hope my solution is very helpful to you.

ignition relay if good ===ignition switch.

resistor.............tell the mehanic