Volvo Glow Plug Resistance

gstraub · #1 (**permalink**) 01-20-2010

I have a Volvo MD2040B that is being a little cranky in the cold. To rule out a glow plug problem, I measured the resistance of each glow plug to the engine block. Manual says the resistance should be 1.6 +/- 0.16 ohms. Each of the glow plugs measured 0.6 ohms. Looking on the net at other types of glow plugs, 0.6 ohms doe not seem unreasonable, but it sure isn't what the manual says.

So, since all three measure exactly the same, I'm wondering if these are really ok, in spite of not measuring what the manual says. Anyone got any thoughts?

Gerhard

CarelessNavigator · #2 (**permalink**) 01-20-2010

Try putting voltage through them. Two jumper leads and a 12v battery is all you'll need and something to hold the glow plug they get hot in a jiffy. I wouldn't apply voltage for more than a couple seconds. you will know if they are good or not.

BarryL · #3 (**permalink**) 01-20-2010

Hello,

When I bought my boat the engine would not start when cold. The glow plugs measured about what you have (I don't remember exactly). I ran a jumped wire from the positive terminal on the battery directly to the glow plug. After 30 seconds I tried starting the engine and it fired right up. I just cleaned all the glow plug connections and now things are much better.

Barry

gstraub · #4 (**permalink**) 01-21-2010

Thanks for the comments. I'll pull them and check them that way. At least one of them had a suspect connection, so I'll clean 'em, pull 'em, and see if they warm up.

Gerhard