Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: seattle_Jerry on June 22, 2009, 00:50:30

Title: Fuel pump wires
Post by: seattle_Jerry on June 22, 2009, 00:50:30
I have a 67 230SL and forgot which wire went where on the fuel pump... As it sits mounted in the car does the tan wire go on the right or left. "Logic" dictates that no matter which I choose it will be the opposite.
Title: Re: Fuel pump wires
Post by: waqas on June 22, 2009, 01:58:18
Assuming your wiring is still original, I beleive the brown wire goes to the negative post.

The best way to confirm this is to test the voltage that shows up across the leads when you switch on the ignition. Careful not to cause any sparks back there, especially if any fuel vapours are nearby.
Title: Re: Fuel pump wires
Post by: seattle_Jerry on June 22, 2009, 07:02:49
Yes its original wiring. The question was more which one is the negative post. If it was marked on the body I can't tell due to surface corrosion.
Title: Re: Fuel pump wires
Post by: Naj ✝︎ on June 22, 2009, 08:15:59
This may help:

Not very good pic  :-\

naj
Title: Re: Fuel pump wires
Post by: seattle_Jerry on June 22, 2009, 14:06:28
Yeah I saw that pic...but can the wiring really be trusted since all he was doing was testing flow...it didn't matter which direction the pump spun. I guess I can try that way and see if it works...
Title: Re: Fuel pump wires
Post by: Naj ✝︎ on June 22, 2009, 14:21:46
Yeah I saw that pic...but can the wiring really be trusted since all he was doing was testing flow...it didn't matter which direction the pump spun. I guess I can try that way and see if it works...

With the wires turned around, the motor will run in the wrong direction and not pump unless you turn the pipes around as well.

naj
Title: Re: Fuel pump wires
Post by: al_lieffring on June 22, 2009, 19:49:12
If the car has the original large body pump, it doesn't matter, because it is not a permanent magnet motor. it will turn the correct direction no matter how it is hooked up.

The later small body pump does have a permanent magnetic field so it is marked with red and brown plastic on the terminals.

Al
Title: Re: Fuel pump wires
Post by: waqas on June 22, 2009, 20:00:57
Yes its original wiring. The question was more which one is the negative post. If it was marked on the body I can't tell due to surface corrosion.

Sorry, I misunderstood your question. On the old-style pumps (large body), if you look closely directly below the wire-connecting posts, there are some numbers etched into the pump body. These numbers correspond with the numbers in the wiring diagram. The left post should be marked 30 and this is the positive post. The right post should be marked 31 and this is negative.

On the newer-style pumps (small body), the wire connector posts are set inside coloured plastic pieces with moulded polarities for each post. In this case, the negative post is on the left and the positive on the right. (reversed from the large body pumps).

The wire colours are as follows: brown for the negative (ground) and black/white/red patterned for the positive.
Title: Re: Fuel pump wires
Post by: seattle_Jerry on June 23, 2009, 06:21:13
Well my pumps posts plastic surrounds are both off white. I can't read anything etched into the pump body because the body is corroded. I'll take a pic. I'll look up the difference betweeen big and little pumps.
Title: Re: Fuel pump wires
Post by: seattle_Jerry on June 28, 2009, 00:03:49
Positive goes towards the posterior of the car. Brown(-) is right terminal