Author Topic: Wires to fuel injection solenoid  (Read 3639 times)

IXLR8

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Wires to fuel injection solenoid
« on: May 25, 2012, 19:08:45 »
Hi--

In the process of putting everything back together, but I can't recall and can't decpher from the wiring diagram--which wire, brown or black, goes to which terminal on the solenoid?

Thanks in advance--


the other Joe

hands_aus

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Re: Wires to fuel injection solenoid
« Reply #1 on: May 28, 2012, 23:28:38 »
Use your multimeter to test for continuity to earth.
That will identify the earth wire for you, obviously the other wire is the hot wire during start up.

Does the solenoid have one or 2 terminals?
The early ones had 2, the later solenoids have one terminal and are earthed through the solenoid body.
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

IXLR8

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Re: Wires to fuel injection solenoid
« Reply #2 on: May 30, 2012, 02:53:17 »
Thanks, Bob--

I have a solenoid with two terminals. Should I then check which terminal goes to earth and then match that one with the wire that goes to earth?

Thanks,

the other Joe

hands_aus

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Re: Wires to fuel injection solenoid
« Reply #3 on: May 30, 2012, 08:13:06 »
Hey Joe ( OJ )

I just checked the solenoid on my 250sl.
The brown wire is on the terminal closest to the mudguard.

I suggest you have a spare fuse just in case you need it.
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

jacovdw

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Re: Wires to fuel injection solenoid
« Reply #4 on: May 30, 2012, 08:32:00 »
Joe,

If you have a solenoid with 2 terminals at the end, then the coil inside is isolated from the metal casing.

On my 230SL, the previous owner removed the solenoid (what on earth for...  ::) ) and fitted a cover plate on the injection pump.
Also cut the wires to said solenoid and taped it off to fit a really stupid switch under the dash for the CSV only.

Here's what I did when I eventually found a used and fortunately working solenoid:

a) remade the small wiring harness for the solenoid
b) using separate wires, connected the solenoid to the battery to test polarity and stroke
c) I alternated the position of the positive and negative wires relative to the terminals

The combination that gave the best "push" of the plunger was marked and the wiring harness connected accordingly.