BMW Fuel Sender Repair

BMW fuel senderThe fuel gauge on the Bavaria stopped working.

I was hoping that it was only a bad ground connection on the instrument cluster. On my first repair attempt, I hit the top of the dash above the instrument cluster to jostle the connections and take out some frustration. When only the latter worked, I looked at my BMW repair CD.

To test the fuel gauge, the repair manual said to connect the brown-yellow wire on the fuel level sender to ground and to switch on the ignition momentarily. The gauge deflected to full, so I knew the gauge and grounds were OK. But that meant the sender was broke. lists the price of new sender at $261.40 (USD), so that was a good reason to try to fix it.

BMW Fuel Sender Sensor wire routing

After I moved all the crap in the trunk to one side, I lifted the carpet and unscrewed the floor panel covering the gas tank.

The gas tank was full. When I tried pulling the sender out of the tank, (it’s a bayonet mount) gas poured out into the trunk. I decided to take a drive down Highway 1 a little south of Point Lobos to lower the fuel level.

The fuel sender is basically a variable resistor. The float moves up and down a guide rod and is also connected to a wire of known resistance. The change in resistance (by the position of the float) is translated by the fuel gauge as the range from full to empty.

BMW fuel sender repair

One end of the sensor wire had broken off its terminal connection so the wire was now too short to connect to the terminal. I used a piece of 22 gauge solid copper wire (looped and soldered to the connector) to extend the connection so the sensor wire would reach its terminal. Since the sensor wire is a continuous run from one terminal to the other, I had to figure out the routing around the bottom of the sender. It seemed to just wrap around – at least that’s how I did it.

The repair manual says the resistance between the G terminal and minus should measure 3.2 & 73.7 ohms at the extreme positions of the float. I measured 3.4 and 84.7 ohms so at least my repair sorta worked.

Android Macbook

Android running on Late 2006 MacbookI downloaded LiveAndroid, a LiveCD for Android running on x86 platforms from Google Code, to try on my Macintrash.

Currently I am running OS X 10.5.7 and Windows 7 (build 7100) on my Late 2006 Macbook (Core 2 Duo, T7200). I’m also using rEFIt as my boot manager. The Android LiveCD showed up as Tux on the boot screen and I got to the Android desktop with the message, “Please connect charger, the battery is getting low: less than 15% remaining”. I was running on AC and the battery was fully charged. I dismissed that warning and went into the console (alt+F1) to try to configure networking.

Android running on Late 2006 Macbook

The liveandroidv0.2.iso supports DHCP, so I tried to get the network running using the howtouse live-android instructions:

ifconfig eth0 yourip netmask yourip’s mask

e.g. ifconfig eth0 netmask

That resulted in ifconfig SIOSIFADDR: No such device

I also tried ifconfig eth1 but received the same message. I didn’t look at the startup log. What’s the use of anything

Ultrafire C2 modded with a Cree MC-E

Ultrafire C2 with Cree MC-EIn late 2007, I bought a couple of Ultrafire C2 flashlights. They were nicely made for an inexpensive flashlight and they used Cree XR-E LEDs (P4 bin).

Last fall, I modded one of my C2s with a Seoul Semiconductors Z-Power LED P7. The P7 is a quad die LED. I made it direct drive running off a single Li-Ion 18650 battery. There were mods that could be made for a circuit board to drive the P7 but I was too lazy to make one.

I recently found a 3-Mode Regulated Circuit Board for Cree MC-E and SSC P7 LEDs (SKU 1217) sold by that advertises an output current of 2500 mA on high. It has only three modes: high, medium and low. The 17mm diameter of the board is a direct fit in many pills, including a lot of P60s and the Ultrafire C2. I used one of the boards to improve a DealExtreme P60 MC-E drop-in.

I had another of the Shiningbeam boards and a quad die Cree MC-E LED, so I decided to put them in my other Ultrafire C2.

Ultrafire C2 pill with Cree MC-E

I soldered the LED to a trimmed down DealExtreme Star Connection and Heatsink for Cree MC-E LED Emitters – Parallel (SKU 16545). I’m not sure why they call it a parallel board, because each die is separately addressable with the connections on the board. I soldered all the anodes together and all the cathodes together, so it would run in parallel.

With a fully charged Li-Ion 2400 mAh battery, I measured the current at a little over 2700 mA through the tailcap. After five minutes, the flashlight was hot, but not so hot that I couldn’t touch it. It also dimmed slightly from initial turn-on but it is still brighter than my P60 MC-E mod.

With a McClicky switch in the tailcap, this is a really nice, bright flashlight now.

Alfa Romeo Rust Repair

Alfetta Sprint Veloce in primerThe body shop called today to point out some rust they found when they removed the rear bumper (like I didn’t know about this). I guess what they really wanted to tell me was that it was going to cost more money.

I had ladled POR-15 Rust Preventive Paint on the sheet metal above the left bumper shock six years ago when I saw it looking not so good. I tried to put out of my mind the rust that I could see inside the bumper where the rubber had split.

Mo’ money, mo’ money, mo’ money…

So far the body shop has repaired rust in the front rocker panels, around the base of the windshield on the passenger side (without removing the glass), around the right windshield wiper drive shaft, on the door under the driver’s side window, around the rear bumper shock, below the bottom edge of the rear window and the trailing edge of the trunk lid.

Alfa Romeo Sprint Veloce less attractive higher angle

Over the years I had treated those areas with POR-15 and/or Eastwood Rust Encapsulator Paint and that seemed to slow the oxidation down almost completely.

I’d previously done my bush league repair work on the rust on the inner front fender wells and a large hole in the spare tire well – my first attempts at using fiberglass. Those repairs look great if you don’t look at them.

Cree MC-E P60 drop-in Mod

Cree MC-E LED P60 Drop-inI was a little disappointed with my DealExtreme Cree MC-E P60 drop-in (SKU 21037). The specs say that on high, it should be pulling 2800ma and putting out 410 lumens. I measured 1.67A on high with a Li-Ion 18650 battery. But for $23.49 USD, I couldn’t complain too much.

I saw that has a 3-Mode Regulated Circuit Board for Cree MC-E and SSC P7 LEDs (SKU 1217). Their specs say the output current is 2500mA on high. I thought I’d try it as a replacement for the circuit board in my DX drop-in.

It was an easy replacement since the Shiningbeam circuit board diameter is the same 17mm as the DX drop-in board. I am using it in a bored Surefire 6P body with the Surefire 6P bezel and a Solarforce L2-S4 tailcap. SKU 1217

The drop-in was a little loose. I had been using a Malkoff Beryllium-Copper spring washer, but it didn’t work too well this board. I cut one turn of a P60 drop-in spring and it creates a 1mm gap between the bezel and the body, but it works. I also had to put a longer spring on the circuit board because without it, the battery was loose.

After I wired it up, I measured 2.39A on full power with the same battery, so it’s a worthwhile replacement. I don’t have the means to measure the light output except for the current draw but it is much brighter than the stock DX MC-E drop-in – though it still doesn’t look as bright as my direct drive P7 in my Ultrafire C2.

The other nice thing is the Shiningbeam board has Low-Medium-High modes as opposed to the High-Low-Strobe on the stock DX.