glow plug light meaning?
 

if the glow plug light on dash comes on does that mean the glow plugs are ok or could they still be faulty...thanks..

What car/engine?

Still could be something wrong. Best quick check is to disconnect the relay plug and read each plugs resistance. Thats if your relay is mounted in the engine compartment.

1982 non turbo 300d euro....will check glow plugs...thought light wouldn't function if plugs were bad...car not firing up in cold weather...will check valve adjustment

Unless the Euro is different, the light could function normally with one inoperative glow plug. More than one inop plug should cause the pre-glow light to not illuminate. This, of course, assumes that the fault detection circuit is operating normally.

The light will still come on with some plugs bad. I had one bad one (open) a couple months ago and the light still came on as normal. When I first bought the car it had two bad ones (open) and the light would come on but go off again quickly.

I've also seen a 7.3 IDI International do the same with four bad ones.

the light comes on for about 10 seconds..it's easily below freezing out

i read that they could all be out and the light would come on

That is true. The fault detection balances the current between the number one plug and plugs 2-5. If they are all out, there is no imbalance.

But if they are all out, I wouldn't think you could start it at all.

newpastlife,

U can put a voltmeter or 12v test light on a GP terminal see if it is getting voltage when U turn the key switch to the GP position.

P E H

You can also check resistance with an OHM meter. Less than one is good. As you can see I need to replace these, I now have them. Started this morning tho, upper twenties.

Too Many,

U will get more accurate readings if U get a bananna plug test lead for your ohm meter to plug into the terminal holes of the GP cable and an alligator clip for the ground test lead.

A GP that reads 1.7 ohms is probabaly good. What did the other GPs read in ohms.

P E H