The panel is advertised as 12 volt, it says on the label that it is 1.5 amps and 16 volts. It tests out at 23.7 volts -- which won't work with 12 volt devices (that usually tolerate up to 19-19 volts). How do I step it down to serve 12 volt devices.

P/V=A

The panel is rated 6 watts at 12 volts 12 / 6 = 0.5 Amps

So in full sun the panel "should" produce 1/2 Amp at 12 Volts.

What type of 12V bulb and what is its current rating?

have the voltage regulator system checked
in the regulator the voltage controls the amperage allowed and it that unit is not working properly then there will be no current out put
that regulator could be part of the control board for the main ac out put and may have developed a fault in the section for 12 volts on the board
there is a limit on the charge rate for the battery and if it is exceed it may have damaged that circuit or possible blown a fuse in the amperage circuit

Wire a 12 volt AC adapter to it. Connect the power to the positive wire, & the ground to the negative wire. If it's a low power unit a 1 amp adapter will work. If it's a high powered unit you might need a 12 volt 5-10 amp adapter designed for monitors, TVs, monitors, & some laptops. Beware some laptop AC adapters can be 16-36 volts. Make sure you use a 12 volt one, & know which wire is positive, or you'll burn it out.

If you have (90) 50w lamps = 4500 watts total. Assuming a 120/240 panel, if you put 1/2 on one "side" of the panel and the other 1/2 on the other "side" of the panel, that would be 2250 watts on each half. The generator should be rated *at least* 125% of the load; 4500w x 1.25 = 5625W. Using a 4500W generator on this load will cause it to overheat and shorten its life as it is running at 100% of capacity all the time..

One half of the panel is 120V to neutral, and the other is 120V to neutral - or 240V between both circuit breaker terminals. Ohms law for DC circuits and purely resistive AC circuits says Volts x Amps = Watts; or Watts / Volts = Amps. So, 2250W / 120V = 18.75A on each pole of a 2 pole circuit breaker that feeds the sub panel. A #12 copper wire is rated for 20 amps; but as per National Electrical Code - must be de-rated to 80% of rating which means it is good up to 16 amps maximum. A #10 copper wire is rated for 30 amps, but it too must be derated to 80%, making it good for 24 amps maximum. So, if you are going to feed a sub panel supplying (90) 50watt lamps, you will need to run a #10/3 copper cable from a two pole 30 amp circuit breaker at the generator to a 120/240 volt "main lug only" sub panel rated for at least 30 amps.

Divide your load evenly across the sub panel - (4) 15 amps circuits via (2) two pole 15 amp circuit breakers on each "side" of the panel if you run (2) 14/3 cables out to the lights - or (4) single pole 15 amp circuit breakers if you run (4) 14/2 cables out to the lights. No circuit breaker terminal should have more than 23 lamps that means you have (2) w/ 22 lamps and (2) with 23 lamps. The circuit w/ 23 lamps will draw 23 lamps x 50w = 1150W. 1150W / 120V = 9.6A. The 22 lamp load will be 22 x 50w = 1100W. 110W / 120V = 9.2A. Which is well within the 12A maximum allowed (after derating as required by code) by a #14 copper wire rated for 15A.

Good luck!

Check circuit breaker.
Click fully off and then back on.
Check for burned smell at breaker or loose crackling sound that says breaker is bad.

Reset timer. Then Reprogram.
Possible geyser timer manual
http://waterheatertimer.org/pdf/Digital-Geyser-Timer 24H-7-Day-Timer-230V Brochure.pdf

This timer has a non-replaceable internal rechargeable battery.
If battery has gone bad, then timer is defunct.

Use manual override button to turn timer ON-OFF.
Then test across terminals 3 and 4 for 240Volts.
Turn timer OFF, and test across terminals 4 and 5 for 240Volts
If no voltage shows then timer does not have output.

If test shows 80% undervoltage, that can cause load not to activate, depending on type of load.
Have electrician check for voltage issues at power company transformer.

Unknown what load timer is connected to.
Max load for this timer at 240 volts is 3680 watts, 16 amps.
Motor load is 230 volt 8 amps.
Check label on load for watt or amp rating.
Volts x amps = watts
Watts divided by volts = amps

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Hello! I sent a test procedure to you Wednesday evening but It appears you did not receive it ..This is the path for Battery and Ground to pull the crank relay which applies +12 volts to the starter solenoid..Either there is a fault in this path or the starter itself was damaged in the collision...Leaving the ignition switch when in start ...+12 volts on the Yellow wire goes to the Crank fuse (10A)...Other side of fuse is Purple wire to PCM C-2 Pin # 23...+ 12 volts at this point...PCM sends a ground on C-2 pin #76...Yellow/Black wire to crank relay....+ 12 volts from the PCM ABS fuse (10A)...via Park/Neutral switch to crank relay...Relay pulls and applies +12 volts on the Purple wire that goes to the starter...That +12 volts, if there,indicates a starter damaged in the collision...If not there chase it back until you lose it...Would you be so kind as to not rate my solution until the test procedure is accomplished...Send a comment..saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

The FLA (Full Load Amps) for a 1 HP single phase motor is 16 amps at 115 volts. 5% is the maximum allowable volt drop from the main electric panel to the pump per NEC (National Electric Code). When these values are plugged into the volt drop formula, such as this one:
http://www.nooutage.com/vdrop.htm
90 feet is the maximum allowable distance for a #12 copper rated at 75 degrees C.

Simplest test is to leave it on the engine, battery hooked up normally. Run the engine at normal full speed (not just idling) and use your voltmeter to measure the voltage across the battery with your DMM. If you measure 13.5 to 14 volts, your rectifier/regulator is probably OK.
It can't easily be tested off the mower. You'd need a source of AC at 24 volts to simulate the motor's stator winding, and a load that draws about 23 amps at 12 volts.
Don't forget a bad battery can cause failure to charge - it's not always the regulator.

All power adapters usually have a label on the bottom of the adapter that show voltage and current for both the input and output connector, unless that label has been removed. Your KVM switch may have the voltage and current requirements printed on a label on the bottom of the device.