Glow plug relay diesel

There can be several reasons for this. The cheapest reasons to look at are spark to the glow-plugs and fuel to the cylinders. If you have a "ready light" on the dash that tells you when the glow-plugs are ready, you need to listen for the clicking of the glow-plug relay and the blinking of every other light that is on in sync with the clicking sound.

If the clicking and light dimming is not observed your power relay to the glow-plug relay is probably bad. A voltmeter will be needed to test for juice passing through the the power relay. If you have juice going to the glow-plug relay from the power box relay and it does not cycle off and on, your glow-plug relay is bad or the glow-plugs are bad.

You can test the power to each glow-plug with a test light or meter (when the power relay and glow-plug relay are cycling). Glow-plugs are similar to spark plugs and they can be tested. It can be tricky or you can just replace them.

Fuel, this time of year is subject to freeze-ups. Additive will help, noting Diesel additive and NOT gasoline additives. In short, Pyroil makes a starting fuel which has protective oil in the spray to help the cylinders. A spray of starting fluid will diagnose that fuel starvation is the problem. It is tricky to use when the glow-plugs are hot. On injector systems with O rings the cold weather can sometimes cause the O rings to shrink when sitting and leak. Your fuel will run back to the tank. Cranking will not be enough to draw up the fuel. Another way is to change fuel filters BUT to put some diesel into the fuel filter to prime the system. No guaranty that the problem will not reoccur because you have not permanently fixed anything. Hope this helps, if not then something has let loose like a fuelpump.

PDF]STARTING SYSTEM

www.toyota4wd.dk/Teknik/1PZ-1HZ-1HDT/8-ST.pdf Fixed Delay Type (PZJ, HZJ75, HZB and HDB) ex. (Europe and Australia) . ... PlugRelay. To Alternator. Terminal L. Water. Temp. Sensor. Glow. Plug. Resistor. Glow Plug ... HINT: Refer to Diesel Electrical System Diagnosis for inspection ..

On some Models the glow plug Relay does not have an integrated Power Relay. This means there is a second Relay before the glow plug Relay that feeds it power.

You should check the wires running to the glow plug Relay for power with the key ON. Check some other wires off of the Ignition switch to make sure your 20 year old Ignition switch is good.

There are some sites which show vehicle wiring. Autozone has a free section after Registering your vehicle but it takes a little sorting through the Help section. There should be a fuse to protect the above Relays.

Make sure you find the Diesel-equipped wiring circuit. Diesel ignitions are different from gas units.

Firstly fit a manual overide to the heater plugs .relay -push button type switch -wire -connectors ,run a wire direct from battery to relay ,other side to heater plug relay output so it feeds all the heaters ,push button inside cab with a 12v feed from ignition switch running to relay then other side of relay to earth ,leave vehicle on charge often on trickle charge where possible ,also on a full tank of diesel put in a litre of petrol to stop diesel waxing up ,nice old rug or blanket over engine and it will first time every time ,only use the petrol when weather below minus 5c though ,great vehicles these peugeots but i do like my ford transit

If it is cold where you live and this a cold start situation it could be a glow plug or glow plug relay problem.

Above the Relay Panel is the Auxiliary Relay Panel. Has thirteen positions in it.
6 across the top, 7 across the bottom.

Across the bottom the Glow Plug Relay is the fourth one over from the left. It is Number 10.
(180)

if you need connectors and terminals for the glow plug connections under the valve cover, Ford sells then so you don't need a whole $600 harness.

info for your use

Section 03-07B: Glow Plug System 1996 F-250, F-350, F-Super Duty Equipped with 7.3L Diesel Engines Workshop Manual
DESCRIPTION AND OPERATION Glow Plug System The 7.3L diesel engine uses a glow plug system which preheats air in the combustion chamber to improve cold engine starting. The system consists of eight glow plugs, the glow plug control module (12B533), powertrain control module (PCM) (12A650), engine oil temperature (EOT) sensor and barometric pressure sensor (BARO sensor) (12A644). The glow plug system is electronically controlled by the powertrain control module. The powertrain control module energizes the glow plugs immediately after the key is placed in the ON position and then determines how long the glow plugs will be on according to the engine oil temperature and the barometric pressure. The required time for the glow plugs to be energized decreases as the engine oil temperature and barometric pressure increase. The glow plugs are self-regulating, and the powertrain control module controls relay ON time. The powertrain control module protects the glow plugs by energizing them for short durations if the battery voltage is abnormally high.

Possible Causes: Insufficient glow plug ON time will not allow enough heat to accumulate in the combustion chamber to easily facilitate starting. If the glow plug system ON time does not meet any of the specifications in the accompanying chart the problem is most likely a faulty wire harness connection, ground connections or glow plug relay.

If the glow plug resistance to ground is high, the most likely causes are an open UVC (under valve cover) harness or open glow plug.
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Relay Operation
Install a DVOM on the glow plug feed side of the glow plug relay (large stud with two wires connected). Turn the ignition key to the ON position but do not attempt to start. Note the time in seconds from when the key is turned on and the glow plug relay energizes until the glow plug relay de-energizes. The glow plug relay makes a loud click noise which is easily heard when it energizes and de-energizes. The dome light will dim and the dash voltmeter will dip when the glow plugs are drawing current from the battery. Compare the times measured to the table (time will be affected by engine temperature, battery condition and vehicle altitude). The voltage at the glow plug feed terminal may vary from 9 to 12 volts depending upon battery condition.
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If battery voltage not present check for B+ at power supply terminal (terminal with single large wire). Power for glow plug power supply is supplied from starter relay through two fusible links at solenoid.
Glow Plug Operation
Disconnect all of the glow plug/injector harness connectors from the valve cover gaskets. With the pigtail installed, measure glow plug resistance to ground (preferably B-). A resistance measurement of .1 to 6 ohms indicates a good glow plug.



Glow Plug Harness Continuity
Measure for continuity from the connector harness to the glow plug feed terminal on the glow plug relay. Resistance should be less than 5 ohms.
Incorrect measurements will result if all glow plug/injector connectors to valve cover are not disconnected.

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Glow Plug Relay The glow plug relay (12A343) has a plastic base and two mounting bolts. It is operated by the powertrain control module (PCM) (12A650) which senses engine oil temperature, PCM voltage and barometric pressure. When the engine oil temperature or the barometric pressure is low, the PCM activates the glow plug relay and the glow plugs. If the PCM voltage is too high, the powertrain control module deactivates the glow plug relay and the glow plugs immediately energize for a shorter duration, decreasing the modulation of the duty cycle.
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Glow Plug Removal

1. WARNING: THE RED-STRIPED WIRING HARNESS CARRIES 115V DC. SEVERE ELECTRICAL SHOCK MAY BE RECEIVED. DO NOT PIERCE.
   Remove valve cover (6582). Refer to Section 03-01D .
   

1. Disconnect glow plug electrical connector using a pair of pliers.
   

1. Remove glow plug using 10mm socket.
   

1. Clean and inspect glow plug tip for damage. Replace if damaged.
   

Installation

1. Install glow plug and tighten to 19 Nm (14 lb-ft).
   

1. Connect glow plug electrical connector. Make sure glow plug wiring is routed to avoid moving parts.
   

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Glow Plug Control Glow plugs are used to warm the cylinders to improve cold-engine starting. The PCM uses the engine oil temperature (EOT) sensor and barometric pressure (BARO) sensor to determine how long the glow plugs will be on. The PCM energizes the glow plugs longer if the engine is very cold or if the barometric pressure is low at high altitudes.
The PCM controls the relay that supplies power to the glow plugs with the glow plug control (GPC) signal. When the GPC signal is grounded by the PCM the relay closes, turning the glow plugs on.
The glow plugs are controlled by the following sequence:

1. PCM energizes the glow plugs.

1. The PCM energizes the glow plugs immediately after the ignition is placed in the ON position.

1. The PCM then determines how long glow plugs will be on based on EOT sensor and the BARO sensor. The required time to warm up the cylinder decreases the engine oil temperature and barometric pressure increases at low altitudes.

Glow Plug Lamp Control The glow plug lamp (GPL) signal controls the WAIT TO START light located on the instrument panel. This light is used to indicate when to start the engine. The cylinders are being warmed by the glow plugs during and after this light is lit. The PCM energizes the glow plug lamp longer if the engine is very cold or if the barometric pressure is low.
When the GPL signal is brought low, the "Wait to Start" lamp is turned on.
The glow plug lamp is controlled by the following sequence:

1. PCM lights the WAIT TO START light after a key on reset occurs.

The PCM determines the glow plug lamp activation time based on engine oil temperature, barometric pressure and battery voltage.

1. PCM turns off the WAIT TO START light.

The glow plug lamp is turned off when the timer counts to the number of seconds specified by the PCM. The glow plugs will normally remain on longer than the "Wait to Start" lamp.
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Check the glow plug thermo sensor...found in the cylinder head.
Unlightly anything wrong with injector pump.
Good luck
John

Maybee there is a short in the wiring...Or try replacing the glow plugs and glow plug relay..