PLEASE NOTE: Wire color may be all red or all black (depending on stock on hand) Performing some fuel pressure tests on your K-jet or KE-jet engine is safer and less hassle with the engine NOT running. The only way you can do that is to find a way for the fuel pump to run all the time while doing the test or any adjustment. When you turn the key on, the pump will only run for a few seconds and then shut off. There are at least two ways you can get the pump(s) to run constantly. On the 560SL, there are three ways. Let Kent explain in the video below: PLEASE NOTE: We now offer only one power lead setup for both single and dual fuel pump models.
Product Details
First method: Find and remove the fuel pump relay and "jumper" the two pins that power the pump. The banana plug ends on this jumper lead will plug right into the socket holes where the relay is mounted. That is pretty easy on some models like the W126, but on the R107, it is a big pain to get to.
Second method: Install the three supplied alligator clips on the ends of the banana plugs. Run this single wire from the positive terminal on your battery to the back of your car where the fuel pumps are mounted. Find the positive leads on the fuel pump ( not the brown wire as it is ground). Leave the button off when doing this. Remove the one OR two factory power wires at the pump(s). Clip one or both ends with two alligator clips to the one or two pump terminals. Clip the other alligator clip onto the positive post of the battery. Turn the button on and listen for the whir of the pumps. If it runs, you are hooked up correctly. If it does not run, switch it off immediately and make sure you don't have the wires crossed. The switch that is located in the middle of the jumper will allow you to turn the pump or pumps on and off at will.
One end has a larger clamp to hook up to the positive on a battery or battery booster ( disregard the colors of the clamps on each end of the jumper).
The other end of the 12 foot extension has two smaller alligator clips to hook on the the positive post of one or two fuel pumps.
The 14 foot wire we ship will either be red or black depending on supply issues. You use only ONE wire from the battery to the fuel pumps so there is no polarity issues and color does not matter.
PLEASE READ CAREFULLY BEFORE PURCHASING: We will provide general instructions, but we are not able to give specific fuel pump relay locations for each model from 1976 to 1993 ( a couple of examples will be shown ). We will not supply you with the pin numbers you need to "jump" with this wire on your model. There are too many variables. Keep in mind YOU can find this information if you do a thorough and deep internet search. If you can find a PDF of the printed service manual, you will have this information along with the pressure test values you will need when pressure testing your car's fuel injection system.
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