I ran some checks including those mentioned above, but didn't find any issues. Then I thought about the battery. It's a 17-year old Johnson Controls 26R. I swap it back and forth between the Merc and my '91 MR2 in the May/June and Nov/Dec time frames because I drive the Merc in the winter and MR2 in the summer, so each spends about six months a year in a remote storage location due to lack of garage space at my house.

The 26R is OE on neither, but it fits both the Merc (Group 48) and MR2 (Group 35), is lighter than the OE batteries, and had plenty of cranking power when it was young.

I'm surprised it lasted this long because I've killed it stone dead twice, but since I only drive the cars two to four times a month when they are in service, I always fully charge it before driving.

Battery prices are certainly up in the nearly two decades since I've bought one. I recall the current one was about forty bucks and Walmart carries Johnson Controls 26Rs for only fifty bucks, but the stock in my local store was old. I wanted a fresh one. Finally last week I found some new stock manufactured in November, so they were no more than one month old.

The new one is rated at 540 CCA and I recall the old one was 440, but the new one is actually one pound lighter at 28.4 compared to 29.4 pounds.

Prior to installation I charged it, and it only took a few minutes to come up to full charge.

With the new battery the first cold start was nearly instantaneous as were the three subsequent hot starts during the drive with no need to goose the throttle once it fired to keep it running for the first few seconds.

The low cranking speed meant low cranking voltage, and my theory is that this caused problems with the "e-part" of the KE system that has all the cold start enhancements and also the ISV, and I expect this was also the likely the cause of the electrical gremlins I reported.

In any event, I guess it doesn't pay to run a battery to its nearly last gasp, but I sure got my money's worth out of the old battery!

The 26R has plenty of cranking power for any four or six cylinder gasoline engine engine Mercs of the era, but I'm not sure about V-8s and diesels. The built in plastic handle makes it easy to install and remove. You don't need the top spacer to mount in a Merc, but I do need it to install in the MR2.

Prior to installation I pealed off the visible labels and reinstalled them on the back side of the battery that faces the electrical compartment cover, so they aren't visible with the battery installed. All you see is a plain black battery without any gaudy labels, so it's practically invisible.


Duke