Checking coolant with multimeter

Oh, hey. You could take that DC voltage present in the coolant and use it to generate some "HHO" gas that you can burn along with the gasoline.

 

Probably why I had to replace the heater coil and water pump at the same time on the 03 Dakota I traded off last year. It only had just over 36,000 miles on it but I never changed the antifreeze. I was the 3rd owner..

 

I bet you could run more LED's straight off your radiator fill cap.

 

Me either even after 35+ years of vehicle repair before switching to electronics. On the electrical side it seems fraught with errors

 

Never heard of testing coolant however have tested wet cell batteries for years by immersing copper leads into the acid without touching the plates to check individual cell voltages but alas that's an entirely different thing than electricity present in coolant. I can see where at milli-volt readings the testing standards could be wrought with inaccuracies due to the type of metal on the lead, the person touching one or both of the leads etc.

 

Ok here is a test hold your DVM leads in both hands with your thumbs one each lead and see what you get. What does the reading represent? Don't ask me I have no clue but there is voltage present frankly I think it pretty much the same thing as sticking them in antifreeze

 

There seems to be more concern in the automotive industry about the pH of the coolant (acid or base) - with regard to the great number of cast aluminum components, radiators and so on these days. If the multi-meter is being used to test for pH of the fluid (by detecting current), that would make sense. A pH number of 7.0 is neutral and it seems to me I recall a number of 9.0 or higher recommended by GM.......

 

You can't test pH with a multimeter

Buy the coolant testing strips and give up on the multi meter people.

This thread makes all of the less mechanically inclined people even worse off

 

Hydrometer and test strips for Ph value...

 

Seems to me the explanation GM gave for the necessity of keeping the pH well above acidic (above 7.0) was the prevention of "electrolysis" - which implies current flow, correct? The test strips seem more like the "right way" to be checking pH and I've used them before on the service trucks we were running.

 

You can test ph levels with electronic devices and it's the most accurate, the multi meter is the least accurate of electronic methods. The probes of ph meters are gaped to a standard so the readings are repeatable. There are just too many variables’ sticking a single probe into a radiator. a litmus test works every time and is plenty close enough. The added water mix alone will change the ph level.