It turns out that my ScanGuage II sucks a lot of amperage through the fuse which is used to power the cigarette lighter.
In the past, I powered a small inverter or a small compressor off the cigarette lighter outlet.
Since the ScanGuage II install, both the compressor or the inverter will blow the cig lighter fuse.

When the fuse blows the ScanGuage II goes out too.
When I install a new 20 amp fuse there is a pretty good spark at the fuse when it is inserted - and the ScanGuage II immediately turns on with some type of "reset" message on it's screen.

Guess it's time to buy a new truck with the built-in AC outlet.

.

Can't see how it would draw more than and amp or so. It's just listening to the Canbus in your truck. I would contact linear logic it may have a short or something. I know mine doesn't suck.

Something is wrong with ScanGauge II. Don't use it, as it might have a short in it, as Weld said.

1. possibly wiring in cig lighter circuit compromised
2. possible something wrong with the cig lighter outlet (they can short circuit when something is plugged in)
3. possibly something wrong with ScanGauge as mentioned, but would be first I've heard of causing a large parasitic draw from these devices.

Harry

Forgot to mention, most of the time when I see cig lighter fuses blown, it's from a faulty cord thats being plugged in, for instance a bad phone charger cord blowing the lighter fuse is very common. If both devices your plugging in are doing this, then thats not it, but if only one of the devices is causing it, take a closer look at the power cord.

Harry

One device is an inverter to keep the laptop charged.
The other device is a small compressor (think "mini-compressor")
Each device alone works properly when plugged into the cig lighter.
The cigarette lighter works too.
Its only when the ScanGuage II is connected does the cig lighter not support the other devices.
Note: exception is cell phone charging - very low current draw. Even the inverter will run for a short period of time - maybe 15 - 20 seconds before the fuse will blow.

Ford factory manual shows a 20 amp fuse at location #12 for the cig lighter and the OBDII port.
A search of the ScanGuage II website and product manual did not find the current draw for their device.

I suspect that my ScanGuage II draws more power than one would expect or mine is defective (even though it works properly in every other aspect).

I suspect you may be right, thanks for the clear explanation Rich.

I wouldn't think the ScanGaugeII should draw much more than 1 to 3amps at the most. Even an electric fuel pump ony draws around 8amps average.

Only way to know for sure is to jump an amp meter inline through the fuse or use a circuit breaker installed through the fuse and monitor dc current draw with a meter or high quality amp clamp, preferably one that reads milliamps (1000mA = 1 Amp).

I've used both my phone charger / portable gps / portable dvd player with no issues on our truck.

I would contact Linear Logic, the manufacturer of ScanGauge and pick there brain, they may have an answer. They usually respond to all questions.

Harry

I sent an email to linear logic. It's basically like a USB or Ethernet device and I can't imagine it draws much more than 1 amp.

I just thought of something. Maybe try it with just the SG2 cord plugged into the OBD2 with out the SG2 hooked up. If it still blows the fuse with just the SG2 cord, then it's a faulty cord.

Harry

The response.


The ScanGauge II should not drain the vehicle's battery or cause a fuse to blow. The SG2 draws 2mA when the vehicle is turned off. With the vehicle and ScanGauge on with full brightness the draw is 100mA. The cigarette lighter and the OBDII port use the same fuse in some vehicles. In one post the customer mentioned it only happens when the ScanGauge is plugged in and when his cell phone is charging. I am curious if it happens when just the ScanGauge is plugged in with no other devices/inverters plugged in. If it happens when his cellphone is charging as well, it may not be an issue with the unit but may be an issue with the wiring. It is possible that the cable or unit may have a short in it, testing out just the cable plugged in like harry6.0 suggested will tell me if it is the cable or the unit. Please let this customer know to contact us, so I can ask a few clarifying questions.

Regards,

Cristina Bollinger
Repairs and Technical Support
Linear Logic
1.888.433.5664