My glow plugs are not working... they all read 1ohm and so are good as new and there is no power to the rail. I have checked the fuses inside the car and all seem good. Is there another location for the fuse for the glow plugs? I looked under the cover for the battery and there's some electrical there but all seems ok. not sure where the relay is for the glow plugs and how could this be tested? car is an 02 golf tdi

check you have power at the glow plugs . fit test light clamp to ground and probe the glow plug rail if no power check fuse if fuse is good check relay if relay is good take vehicle to your mosy trusted garage

Hi Margaret , Does the glow plug wait to start indicator light on the dash come on ? And then go off after a couple of min. ? Check fuse K 20 amp in the under hood fuse box .This is one of three B+ power supplies to the glow plug control module > Two fusible link's are also B+ power supplies to the module . There is a 10 amp fuse located in the inside fuse box , fuse # 17 , this is power for the indicator light !

the glow plugs have a rail/wire that joins /links all of them that rail receives 12volts across it ,check that it is not touching against any metal earth surface ,if it seems to be fine disconnect the power wire to the rail and insulate wire .Then refit fuse and turn on key ,if the fuse blows you know that there is a short in the wiring going to the glow plugs ,if the fuse does not blow it is highly likely that one of the glow plugs has shorted and needs replacing

2 ways to check 1) have key out of ignition, remove glow plug power rail, get ohm meter on top of glow plug where rail bolts on & base of plug where you bolt it in. check all plugs & should be similar. 2) remove plugs & hook jumper leads to battry, connect - jump lead to base of plug where it screws into the block, touch tip of plug where power rail bolts on with the + jumper lead but do not touch the heating element of the plug extremely hot extremely quick. hold power on for 5 - 7 sec until glow bright red. repeat with all plugs (faulty ones will take longer to glow or not glow at all)

HI. Usually, when this light illuminates, it will signal that one, or more of the glow plugs are malfunctioning. I recommend to test all glow plugs, so that you may isolate the defective plug.

A test light can be used to determine if the glow plugs are working.


1. With the test-light grounded, insert the test light probe into a glow-plug wire to check for continuity.

2. If the light comes on, check the other cylinders in the same manner. If the test light failed to light, check for continuity at the glow-plug relay.

3. If no power is present, check the control circuit of the glow plug relay.

4. If the control circuit is working, the relay may be defective (FYI, manufacturers may have the system fused and fusible links may be located throughout the system).

5. If the glow-plug circuit is working, the glow plugs themselves may be defective.

Checking glow-plug resistance:(Remove the plug for this test)

1. With an ohmmeter, connect one lead to the terminal and the other lead to the body.

2. Read the resistance and compare to specifications.

3. A visual inspection may also be necessary to check for excessive carbon buildup and physical damage to the tip.

4. A glow plug that has excessive carbon deposits on its tip can give the correct ohmmeter reading but still not work. Clean the tip with carbon cleaner.(DO NOT USE A BRUSH TIP CLEANER)

In most cases it is not the relay, although the Glow plugs operate on a reduced voltage, that is where to start checking.
Glow plugs are installed just like Spark Plugs in a Gasoline Engine, use a Long Shank removal socket to extract them, ease them out and make sure they are a snug tight fit on installation
Remove ALL Glow plugs. Set up a 12 or 14 guage wire bared at both ends, that will be long enough to connect to the Positive terminal of the battery, to the opposite Negative.
With the Positive end of the wire connected, take a Golw plug and Press it against the Negative Terminal of the Battery, and at the same time touch the Pos. Wire on to the Center Power terminal of the Glow Plug. If the Plug is GOOD it will start to SMOKE in 3-4 seconds and get HOT. Repeat the procedure with the other 3. If the failure rate is more than 2 out of 4 discard all plugs and install new. If less, replace only the junk ones. If all plugs are Good replace the Power Timer relay on the Vehicle. It is cost effective to check the Plugs first. But at the same time with a Volt Meter check the Power reading at the Glow plug Connection terminal.

Best of luck in your endevours.
Regards,DT

The first thing to do is locate the owner manual.

Look for the glow plug relay MAIN FUSE location.

The glow plug portion of your van is not working.

This difficulty scale from 1 to 10 is a 9.

You will need a DVM and tool undo the cables to each glow plugs.

It's a 1 to 2 hours troubleshooting job.

I'm going to fire off a quick list

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Check / replace blown glow plug relay main fuse
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Disconnect each center nut of the glow plug wire. PLEASE CHECK ONE AT A TIME.

Read the resistance between the center of the glow plug and the metal base of the plug.

Please take good note on each glow plug resistance reading.

MAKE SURE all cables are put back and tighten properly.

Compare the resistance on all cylinders.

OPEN/high resistance is bad glow plug.

In general 3 ohm or less is OK.

You should buy one and use its value as baseline.

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Glow plug relay can be bad.

You will need the VOM and a friend to turn the key.

Check the voltage to each glow plugs. It should be 12.6-13.6 volt.

Be careful,the plugs will get HOT.

Compare the voltage on each cylinders.

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So the problem can be combination of

glow plug relay

glow plug relay main fuse

glow plugs

ignition switch is unlikely but I'm going to list it anyway.

Once again,this is a difficult and time consuming job. I will ask a friend to help out,

Good luck.

Check the fuse first then check the wire harness and connection working your way back from the glow plug to the fuse box. Good luck and hope this helps. If everything is good then replace the glow plugs. 

possible short in wireing

Bad glow plugs most probably or the glow plug controller. to check your glow plugs remove wire and check with ohm meter to ground. if they are working you should get a low ohm reading if one has a high ohm reading it is bad. if all injectors check good make sure your fuses are ok, also check and see if you hear the controller click when you turn the key to on. Does the wait to start light come on?