Thursday Aug 20, 2020
1993 Honda Ignition Switch Failure

Several days ago I washed the car - and engine bay - at a wash-it-yourself car wash. When washing the engine bay I use only low pressure as I don't want to force water into electrical circuitry. From the car wash, the car started and ran as expected. The next day, for the first start of the day, the car exhibited a known condition - start then die. A relay is the typical cause where I've replaced the relay a couple times on this car (Thanks to Luke for the suggestion to replace the part when I first encountered it). It's a condition that can act up for a week or two with the car reliably running (once it stays running). I thought - that's a bit odd - I replaced that relay last summer - it should have many years before giving issues again. I put it on my radar for replacement again and continued to drive.

On a trip just out of town, cruising the highway (65MPH), the tach and speedo indicator arms dropped to zero. The LED clock on the dashboard turned off - though the engine continued to have power - and the items just as quickly went back to normal. This was a new issue. My mind went to - DRAT - a new issue - did the water from the car wash get into a computer where it's now failing? Such an electrical issue could be the end of the car.

At a stop out of town I left the engine running - and it kept running as desired. Back on the highway to home the needle drop / clock off condition happened a time or two. One of the times the clock and needles quickly flickered - off / on. Finally the engine died. I coasted into a parking lot and tried starting - it started. Back on the road a comment to Dad/Uncle Bill/Grandpa (the car guys in the family) - help me find the solution. Diagnosing a sporatic electrical issue can be difficult. The car kept rolling, getting closer to town.

At an "outside of town" stop light the engine died but I was rolling enough to get off of the road. No start this time. I'd turn the key to START and the car would start as normal but as I'd let off of the key (to RUN), it'd die. Hmmm... This starter has 320,000 miles and 27 years, the brushes must be getting low/old where starter replacement is on the radar - maybe I'll just hold the key to START and drive home. Perhaps I could disconnect the starter cable, once started, and not abuse the starter assembly and still get home. As I sat in the car, starter giving some grinding noise I gently turned the key back off of START and the stater went silent - with the motor still running. Hmmm - there's a small window between START and RUN where I can get what I want - a running car with no starter running - IF I HOLD THE KEY JUST RIGHT. That's good by me - let's get rolling to home (auto trans makes this a piece of cake).

About 20 minutes to travel the distance I found that I could, at highway speed, let go of the key to shake off the cramp in my hand. I'd then turn the key just right and the motor would come back to life, still turning from coasting down the road "in gear".

Going through my mind - it looks like the solution is known - Thanks Dad! - ignition switch.

Back at town - take the steering column apart to remove the switch (10 minutes). Inserting a screw driver into the switch - to turn it just as the key would - the issue replicates. Turn to START and the car starts. Let go for RUN and the engine dies. Turn to START and back off "just enough" and the engine keeps running. Let's look to replace the switch. Honda no longer offers the part (drat - I'd be pleased to have a Honda part to get another 300,000 miles and 27 years) so generic third-party it'll be. In stock nearby.

New switch assembly installed - issue tended.

Yes, an older car. Little things will crop up. What will be next...and when?

Perhaps I should add fuel pump and filter to the replace list (along with the starter) to be preventative.

The old ignition switch assembly

When I removed the cover from the electrical contacts, a blob of solder fell onto the floor (long ago cooled to solid). The electrical contact had enough current passing through to heat the solder to melting point.

"Run" contact (green line) shows issues.