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90 XJS V-12 Battery Drain

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Hello all!:

I swapped the fuel pump and master relays with another set.

problem is still there.

The sound that I hear with the stethyscope is from touching the fuel pump below the battery. It is not running at high speed or at least it sounds slower than when the engine is running.

The sound is there if I pull the relays.

I presume that the relay with the red diagonal strioe goes in the red connector and the other in the black. Correct?

The relays are different part numbers and the wiring diagram says one has a diode inside.

It appears that this is a short of some type.

More to come.

Pr
 
Michaael, If your fuel pump still runs with the igniton switched to off, you have to have a wiring annomally problem. You need a detailed diagram of the fuel pump circuitry to trace all possible wiring faullts. I can supply a wiring diagram if you do not have access. Is your year model a 90 or 91? I would go at the problem by tracing where the 12 volts to the fuel pummp is coming from when the ignition is switched off. The fuel pump will run a little slower when the engine is not running and consuming gasoline. Do not be concerned over that. The major point is that you are getting 12 volts to the fuel pump when it is not possible if the wiring is correct. Regarding your idle speed. the main control of idle speed is a 13mm or 14mm hex head bolt on the rear of the left (B bank) intake manifold. If you have not tried to adjust this, do it now. Idle speed is not set in Jag fuel injection by adjusting the butterfly valve openings. Let me know the results of the above. If you need it I can send the fuel pump power curcuitry. Jack
 
John;

I have the idle adjustment on the AAV screwed all the way in. The valve is new (about one year old)and I tested it before I installed it with the boiling water test.

I have a wiring diagram manual that gives the separate wiring diagrams.

More to come
 
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