Lost engine power, dash lights while driving

Driving home, the engine rpm dropped to zero and I lost dash lights, window power and clock has gone out.

The radio works and so do the head lights and interior lights.

I have replaced the main relay with no positive outcome. Waiting for AAA.

Has anyone in prime run into this problem, or have any ideas where to look first?

Same thing happened to me years ago during a canyon run. The car would just die down while on the freeway but It started up again as soon as the tow truck arrived. I didn't want to take the risk of being stranded so I had it towed to my garage. It always starts up since then but I went ahead and replaced the main relay anyways. So far the issue never came back and this 4 years ago.

Try to start again after an hour or so.

Have the alternator checked.

Your car is a '91 so it doesn't have an immobilizer. You don't have some after market security system that might have failed, do you?

The fact that your car is 24 years old and the dash lights went out makes me think that its probably the ignition switch. A main relay failure would not cause the dash lights to go out. The ignition switch has two circuits in the running position. The ECU and some other stuff are on the IG1 circuit and a bunch of other stuff on the IG2 circuit. The contact in the switch that supplies the IG1 circuit could have failed while the IG2 contact remains operational. It is also possible that the #29 fuse that supplies the IG1 and starter circuit in the ignition switch has blown. If you can crank the starter motor, then the #29 fuse is OK and the problem is likely in the switch itself. If the starter motor will not operate, then the #29 fuse may have blown. If the #29 fuse is blown, then you could try replacing it and see if that solves the problem; however, a blown fuse is a just a symptom usually indicating that you have a short somewhere.

Try wiggling your ignition key and switching from the ACC to the run position. Sometimes that will get the switch working temporarily. If it does, that's great and plan for immediate replacement of the switch.

Its also possible that the switch is OK and that you have a broken wire or bad connection some place. I have seen the wiring under the dash on the NSX. Trust me when I say that a failed switch is the absolute best possible scenario!

The switch can also be cleaned if the contacts are not pitted badly. (There's an old thread on Prime on this topic) Buy a new one, open up the old one, clean it and keep it as an emergency spare.

Thanks jagtiger. Unfortunately it will not start anymore.

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Thank you Old Guy for your comments. I have checked the #29 fuse which is still good. Also check the other fuses in each of the fuse boxes. My car does have an after market alarm that I do not use, but one time the alarm did trigger the immobilizer but the lights on the gauges still worked.
I did change the ignition switch like 7-10 years ago so I'll check that again.
Will give an update after checking the ignition switch.

I checked the wiring diagram. The ECU and the instrument cluster are definitely off the same IG1 circuit. The headlights and interior lights are not on a circuit controlled by the ignition switch so they would be unaffected and the radio is on a separate circuit from IG1. An ignition switch failing after only 10 years would be unusual. Definitely check it out using the test procedure in the service manual; however, the problem may be wiring.

Ignition switch. A similar experience happened to me. I was on the freeway and the dash cluster went kaput and the engine stopped...then a second later everything went back to normal. This happened a few more times and finally took it into a shop. The contacts on the ignition switch had gotten messed up (probably from over use); got it replaced and the car runs fine.

Today I changed the ignition switch and so far so good. All lights are working again and started right up.
Surprised the ignition switch only lasted 10 years. And I only drive about 3000 miles a year. Well thank goodness it was something small.
Thanks to everyone for their input and help.

Is there any warning with the faulty ignition switch or it just die?

rednsx2 said:

Today I changed the ignition switch and so far so good. All lights are working again and started right up.
Surprised the ignition switch only lasted 10 years. And I only drive about 3000 miles a year. Well thank goodness it was something small.
Thanks to everyone for their input and help.

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The first time I had the problem, The car would not start. When in position 2, no clicking sound as normal. All the dash lights would come on, but it just wouldn't start. It would take multiple trys.

This time I was on the freeway and the engine, cut off but the lights on the dash were still on. I shifted into 3rd and the pop the clutch and the engine restarted. This last time, I thought if it happend again I could just pop the clutch again. I was wrong. All dash lights and power windows did not work no matter how many times I tried.

I have not had time to open up the old ignition switch yet, but all I recommend is if you are having simular problems, change it out.

nis350 said:

Is there any warning with the faulty ignition switch or it just die?

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A lot of the time, as the switch ages / wears, the car will momentarily die when hitting a bump or anything that causes the internal contacts of the switch to momentarily open. However, sometimes the dying bit is not momentary. Luck of the draw!

If you are experiencing momentary hesitations when you hit a bump including loss of instruments and sometimes other electrics, time to investigate the switch!

It's good to know. Thanks for the info.