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j4jacob
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Power to my fuel pump is cutting in and out.   Anyone know where the inertia switch is in a Jensen GT?

Thanks in advance,  Albert

 

Greg Fletcher
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Joined: 03-11-2005
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I didn't see that in the Jensen Parts Catalogue Supplement, do you know if an Inertia switch fuel cut off was orginally fitted to GTs?

Seems ironic that an automaker that installed a plastic fuel T on the assembly line would make an effort to install such a device on the same car.

Judson Manning
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Greg think back to a time before Ralph Nader and the 1975 roll over standards. 

I have seen a mercury switch somewhere in the engine compartment designed to shut off the fuel pump in case of roll-over.  Wish I could be of more help with exact location.

j4jacob
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    Thanks Greg and Judson.  The inertia switch was actually not hard to find once I took the time to really look around.  At least in the GT (probably later model J-Hs as well) it is a  orange cylinder with a viewing glass on top.  About 1/3 the size of a soda can and mounted in a prominent place on the fire wall.  The way it works is simple.  There is a marble-sized ball bearing in a cradle at the top of the cylinder held in place by a spring and visible through the viewing glass (actually plastic).  When the car is hit (or the switch is jarred) the ball bearing is knocked out of the cradle.   Once displaced, the spring  pushes the cradle to the top of the cylinder which breakes the circuit and shuts off the fuel pump.   It can easily be reset by pulling back on the spring via a trigger on the side of the cylinder and relocating the ball to the cradle.  In my case the contacts inside the switch, and the wire terminal clips to the switch were gunked up.  Cleaned this up and no more side-of-the-road adventures....for now. 

If anyone else wants to find this thing and service it just unplug it, remove the two screws holding the looking glass on and the whole thing comes apart.  Watch the spring!  And be careful with the contacts inside the switch.  They are delicate and if you stretch the contacts too far open while cleaning they will no longer, well, make contact.  I used wd-40 and a piece of fine grit sand paper which worked fine.

Albert




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