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Ehhemm
17th December 2022, 02:47 PM
Hi all, i have Y61 2000 model Patrol whith ZD30 motor and during a -8 Celcius Cold start it draws 9 Amp for 4.30 minutes. The next job is to Ohm the glow plugs but are 9 Amps normal current consumption?

Br.
Elmar

BrazilianY60
18th December 2022, 12:44 AM
Hi Elmar! I have loved your approach!! What are you using for dataloging?

I don't have a ZD30 nor do I live in a cold place, but 9A over 4 minutes doesn't seem right. The attached PDF contains the Glow Control System pages extracted from the Engine Control chapter of the service manual. It mentions that voltage should drop to zero no longer then 20 seconds after turning on. Maybe the glow relay is getting stuck at such freezing temperature? Check if the voltage is dropping to zero on the relay signal wires before 20s. If yes and the current is still on the relay high power terminals, then the relay may be the issue. If the voltage does not drop to zero on the signal terminals, then the issue would be upstream in the control system.

86404

Ehhemm
18th December 2022, 01:04 AM
Hi, i am using a Ocilloscope/Picoscope 2206B and a Pico TA018 Ampclamp. On the last page of the PDF the Resistance should be approx 0.5 Ohms at 20° celsius, at 12 volts that is 24 Amps so i have to look at the relay and ohm the glow plugs.

BrazilianY60
18th December 2022, 01:11 AM
I meant more towards the time then the current, as they are supposed to get glowing red quickly, so high current it is, but not over such a long time. It almost seem like it is glowing until the engine reaches working temperature.

Ehhemm
18th December 2022, 04:07 AM
Whith the key in the on position the glow plugs stay on for 20 seconds that fits whith the PDF, it is after start that the Amps fall. Everything gets more difficult when it is this cold the batteries are maybe not in the best condition.

86406

Brissieboy
18th December 2022, 10:26 AM
Hi, i am using a Ocilloscope/Picoscope 2206B and a Pico TA018 Ampclamp. On the last page of the PDF the Resistance should be approx 0.5 Ohms at 20° celsius, at 12 volts that is 24 Amps so i have to look at the relay and ohm the glow plugs.

The glow plugs have a positive temperature coefficient - their resistance increases with temperature. The stated 0.5ohm is cold but will dramatically decrease as soon as they heat up. That is evident in your second picoscope picture where the current drops from around 20+ amps down to around the 8 amps you are measuring.