It's An Imperfect World, Screws Fall Out

One of the frustrating things that occurred during this summer's work on the car was that stuff seems to have broken all on it's own.  Through no intervention on my part, at least two items on the car stopped working.  Trust me when I tell you I've been responsible for breaking a number of things related to the car, but I think I'm innocent here.

After I hooked the batteries back up and turned on the new TBS Link-Pro meter, I had to run through a series of menus to set it up properly.  When it came to the prescaler menu, I selected the 1/10 prescaler because that's what I was using for the older Xantrex Link-10.  To my surprise the meter read that my pack voltage was 68.9 volts.  Well that's a bit off as my pack voltage is 160V.  I double checked the meter looking through all the settings and found everything was correct.  Eventually I pulled the meter out and measured the leads coming from the prescaler itself only to find that the leads which should have read 16V, instead read 6.89V.  Well that put the blame solidly on the prescaler, the meter itself is fine.

I checked and the prescaler was hooked up correctly, after all I hadn't changed any of that.  But there was no doubt about it, the prescaler was spitting out the wrong voltage.  I have no idea why it broke, how it broke or when it broke.  All I know is that when I unhooked the batteries in May, it worked, and when I put them back together in September it didn't. 

Not being an expert in electronic circuits, I have no idea how to fix the prescaler.  As far as I'm concerned, I put 160V on two wires that lead to a little box in which some magic happens, and then on the two wires coming out the other side, there's 16V.  Besides, the unit is sealed.  I was left with one option and that is to replace it. 

I got the replacement 1/10 prescaler and thought I'd measure it before I disassembled the dashboard to put it in.  I carefully hooked it up to the positive and negative leads to the 160V system, and to my amazement the other end read 48.3V.  What the hell!?  Now I had two different prescalers, each of which should be working fine, but both spit out completely different and incorrect voltages.  I sent the new one back at which point they evaluated it and said it was fine.  What!?

I'd ordered the part from Evolve Electrics and was working with Justin Dunn.  It turned out that both of us learned something about this prescaler and the TBS meters.  Both the 1/5 and the 1/10 prescalers will read 48V when hooked up to the pack.  It's only after you hook it to the meter does it somehow adjust the voltage and display it properly.  Like I said before, magic.  Neither of us expected that.  By the way, Justin was great to work with.  I feel quite comfortable recommending Evolve Electrics. 

The second thing that seems to have broken while the car was sitting still was the tachometer.  I drove the car around for a couple days after putting it back on the road, and all was well.  But one evening I left my destination to head home, turned on the lights and found that the tachometer's dial didn't light up.  A few moments later I realized it wasn't working at all!   It had been working when I arrived earlier when the lights weren't on.  When I came to a stop light, I turned off the lights and revved the motor.  Sure enough the tach sprang to life and worked perfectly.  It was hovering at about 2000 RPM and I turned the lights back on and the needle froze where it was. 

I have no idea what would cause such strange behavior, but I do know that I didn't touch any of those systems or their wires when I was performing the work this summer.  But then it just got worse.  A couple weeks ago I was accelerating from a light in second gear.  At about 35 MPH I went to shift to fourth and I noticed that the tach read 5000 RPM.  I thought that was odd because 35 MPH in second gear is about 4000 RPM.  I dropped it into fourth and watched the needle come down to about 3000 RPM, which I know is too high for that speed.  Suddenly the needle jerked up to 5000 RPM, then 6500 RPM.  By the time I finished my trip, the tach's needle had moved well beyond the 8000 RPM top of the dial, and was approaching a full lap coming around to 0 again.  Now the tach just jumps around all over the place providing no useful data.  It's just become a distraction.  I believe I'll be unhooking it.

So what the heck happened to these two pieces of equipment while they were sitting still and not being powered over the summer?  I really wish I knew.  The tach I can live without.  I'll probably replace it at some point, but for now, it stays.  Justin sent the prescaler back to me and I popped it in yesterday.  It works just fine and the meter is behaving like I expected.  If you ever end up with the TBS meter and prescaler combo, don't bother taking a voltage measurement from the prescaler itself, it won't be what you expect it should be.  It has to be hooked up to the meter. 

New Tachometer

The new tachometer arrived last Friday afternoon. I spent some time working to get it to fit into the space available in the instrument cluster. It turned out to fit quite nicely, although it was really tough getting it secured and sealing all the light leaks around the edges. Here's a rather dark shot of the instrument cluster installed in the car.



As you can see, the airbag still needs to be installed. Tomorrow, I'll remove all power from the car, and install the airbag and steering wheel. Next, I need to seal up a few gaps to be sure that the back battery box is water tight. After that's done, the car is coming off the jack stands and I'll be taking it for it's maiden voyage. I'm being encouraged to wash the car first, and I think I may do that. If I'm going to record the first drive, I want it looking good!

Instrument Cluster

When I had first started up the car last week, I had plugged in the instrument console to see what I would get. As I mentioned before, the speedometer worked, which was a big relief. Obviously, the fuel gauge and the temperature gauge did not. Curiously, the fuel gauge was pegged at Empty and temperature sensor showed the car was over heating.

In addition to that, were numerous warning lights that simply wouldn't, and won't go out. There was the Traction Control warning, Low Fuel lamp, over heating warning, ABS light, and of course the Check Engine light. Most of those lights (with the exception of the Check Engine light) I simply removed from the back of the console. They'll never go out, so there's no point in having them there. Of course the other thing that didn't work was the tachometer.

Since I need to replace the tachometer, I want to try to get the new one to look as stock as possible. I realize that the Fates are not behind me on this, but I'm going to try anyway. I want to fit the new one where the old one is. I opened up the cluster to remove the existing tachometer. Here's a shot of the cluster; notice no needle for the tach:


I've ordered a replacement that should fit in the space, and match somewhat closely. The dial is 3 and 3/8" round, it has white numbers and markings that glow red at night; the stock glows orange, but orange wasn't an option. The needle will be white and remain white when illuminated. I'm going to have to carefully cut out the old dial so the new one will fit. So I took the assembly apart so I could get to it.

You can see the old tachometer at the bottom of this shot. It fit into that space just above it in the assembly. If you look at the dial area on the assembly, you'll see a raised piece of plastic that traces the perimeter of the dial at the top with a sort of staggered look to it. That is there simply to distribute light around the dial. I'll likely have to cut the dial out, leaving that light distributor, as well as leaving enough plastic on either side so as not to compromise the structural integrity of the whole assembly. It doesn't need to be too stout, but it does need to hold together while I put it all back together. You can also see in the picture that I've put some shrink tubing on the pins for temperature sensor to the left. I did the same for the gas gauge. This way, they'll just be dead in the console.

I mentioned that I didn't remove the light bulb for the Check Engine light. That's because I intend to use that for the Zilla controller. If the Zilla recognizes a fault situation, it will illuminate that warning light. I've soldered a wire to the circuit board on the back to route the signal to it.

The yellow wire will be connected to a lead that is already in place and runs to the Zilla. The red wire will provide power to the new tachometer for the back lighting. That wire is soldered to the board on a place that only has power when the dash lights are on. So far, so good. Now I just need to wait for the new gauge to show up.

Yesterday, I did one other thing. I thought I'd re-assemble the passenger side dashboard, glove box and all. But last week as I started to fit everything I realized that I'd placed the fuse for the Link 10 meter in a place that can only be accessed if I disassemble the dash. Well that won't do, so I moved it to the electrics bay for easier access.

This means I'll have to re-program the Link 10, which will be OK. Apparently I did something wrong with the first go at programing it. When I came out to look at the care Tuesday, the "Gas gauge" showed that there was only 34 % of the battery's capacity remaining. I know that's not true. While there is a draw on the batteries when the car is off, it's on the order of milliamps. In fact the meter showed that I'd only used 1/2 a kWh since I'd charged the car. That seemed about right with all the testing I've done. But if the meter thinks the batteries have only 34% capacity remaining after I've used 1/2 kWh, then it's set wrong. So, I'll have to sort that out.

Instrument Cluster

One of the things that truly does worry me about all this is how to make all the instruments work. The Zilla controller will run the tachometer, IF I can isolate the leads to it, figure out what each one is and plug them in to the hairball correctly. The Zilla can also use the "Check Engine"light (or any other unused light for that matter) to warn of system faults, again IF I can figure it out.

The tough one is going to be the speedometer. The sensor for the speedo is in the trans axle. It sends a signal to the ECU (Electronic Control Unit, the car's computer) which in turn sends a signal to the instrument cluster. Well, the ECU is effectively dead. At least I think so. It's still there, but of the 6 wiring harnesses that were plugged into it, all but one is gone. My hopes that the one remaining cluster of wires contains both the lead in and out for the speedo, AND the unit will work as designed with no input from an engine are slim.

I may end up having to build something that processes and sends the correct signal to the instrument. Stop laughing! Yeah, I'm not so sure I can do it either. I may be left with no other choice than to use an after market speedo. I think you can see why this part worries me.