Gauge or dongle?

**dgjks6** · 10-18-2016

So I bought a cheap chinese bluetooth dongle OBD2 thing for my phone. It did not have an option for a pontiac so I put in chevrolet. Anyway, it seems to work. Gives RPM's, mileage, coolant temp, and a bunch of other stuff. All seems normal. Says the coolant temp is 195 at normal operating temp and 202 in traffic (this is just below half way on the gauge in the car. Made me feel better. But it says the voltage is 13.7-13.8 and the gauge in the car said 14.7-15.2 volts. Any thoughts on which is right or why there is a difference?

**ILMODC** · 10-19-2016

Nice. Is this for an android phone? I’ve seen those OBD IIreaders and wanted to toy with one. But I have an Iphone. Are they legit?

**Bronco Boy** · 10-19-2016

Put a voltmeter on the battery so you what it really is. From there the answer to your question will be clear. LOL

**dgjks6** · 10-20-2016

I bought a $19 dongle of amazon from china. The instructions are in English - sort of. I have an iphone but there are apps for android or ios. Took less than 5 minutes to set up.

I got to figure this out. The app read 13.7/13.9 the entire ride home. The voltmeter in the DIC read 12.6-12.9 for a while then jumped up to 14.9-15.2 for the second half of the ride. Voltage regulator? I may just swap the alternator to see if this helps.

**rynoman03** · 10-20-2016

Have you put an ohm meter on the battery yet to see what it reads ? Don't just start throwing parts at it because a Chinese bluetooth ODBII reader is off.

Go to the source and read the voltage straight at the battery. Ohm meters are cheap! Esp at Harbor Freight.

Read it without it running, then start the car and read it running and see if it matches your DIC.