P38 1995 Diesel in tank pump plug wire identification

Gary East-Yorks · Jan 29, 2024

Hello folks
please can anyone identify the 4 wires of the fuel tank pump plug, i want to test if i have power to the pump as i have no fuel to the under bonnet filter housing and cant hear the pump running. regards Gary

RangeRoller dt · Jan 29, 2024

With a 95 the pump will only come on with engine running and glows on or if you have a hot start fitted you can cycle ignition.
To test You should power it direct by jumping the relay

Gary East-Yorks · Jan 29, 2024

RangeRoller dt said:
With a 95 the pump will only come on when cranking and glows on or if you have a hot start fitted you can cycle ignition.
To test You should power it direct by jumping the relay

Thanks for the reply, is there a circuit diagram on those relays to identify the pins .

Datatek · Jan 30, 2024

Gary East-Yorks said:
Thanks for the reply, is there a circuit diagram on those relays to identify the pins .

All the diagrams are on RAVE.

Datatek · Jan 30, 2024

RangeRoller dt said:
With a 95 the pump will only come on when cranking and glows on or if you have a hot start fitted you can cycle ignition.
To test You should power it direct by jumping the relay

Surely the 95 only runs the pump when cranking and the glow plugs are on, the third option was added on later models. It also runs of course when the engine is running.

RangeRoller dt · Jan 30, 2024

Datatek said:
Surely the 95 only runs the pump when cranking and the glow plugs are on, the third option was added on later models. It also runs of course when the engine is running.

Yes that is what is said. They fixed it on the later models, this is why they fit a hot start mod to the earlies like ‘95. With the mod the glows and pump will run every time you switch the ignition on.

Datatek · Jan 30, 2024

RangeRoller dt said:
Yes that is what is said. They fixed it on the later models, this is why they fit a hot start mod to the earlies like ‘95. With the mod the glows and pump will run every time you switch the ignition on.

@RangeRoller dt Right, my memory is not so good these days.
On early cars the pump only runs with the glow plugs on or the engine running. Diode D4 was added on later cars to run the pump whilst cranking in an effort to overcome hot starting problems.
The hot start fix causes the pump to run on a hot engine by bringing the glowplugs on.

RangeRoller dt · Jan 30, 2024

I see what you mean I’ve typed it wrong

‘95 is engine running and glows.
Pump only runs while cranking on later models

P38 1995 Diesel in tank pump plug wire identification

Gary East-Yorks

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RangeRoller dt

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Gary East-Yorks

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Datatek

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RangeRoller dt

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RangeRoller dt

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