* Fuel-pump Relay Location in a '77 280E * - PeachParts Mercedes-Benz Forum

mgburg · #1 06-27-2009, 05:19 PM

I need to either locate that sucker (relay) or I'm looking at the fuel-pump or related gear by the rear axle...

Anyone have an idea/picture where this might be located? Or better yet, what fuse would I be looking for under the hood?

Thanx!

t walgamuth · #2 06-27-2009, 08:17 PM

IIRC on my 84 280e it is near the fuse box/ mc area. Its a black relay, about 2/3 the size of a cigarette pack but black and it will say fuel pump relay, 6400 rpm, IIRC. If it is toast of course the pump will not pump.

79Mercy · #3 06-27-2009, 09:12 PM

There is black box on the drivers side fender well under the hood, remove the cover and the fuel pump relay is the farthest one back toward the firwall and farthest towards the right side of the car.

mgburg · #4 06-28-2009, 06:19 AM

I'll check that spot out this afternoon...I just rolled in from a transmitter outage up by Colfax, WI.. The storms that came through last night popped a few breakers, around 6PM, that required an on-site visit to reset...then I had a "safety circuit" wiring issue that cropped up...didn't get the station back on the air 'til 11:30 PM (CDT)...then I drove back after making sure the thing didn't bite me again once I left...now, I have two more e-mails to send and I get to bang my head against a pillow...zzzzzzzzz

mgburg · #5 06-30-2009, 12:02 PM

Quote:

Originally Posted by 79Mercy

There is black box on the drivers side fender well under the hood, remove the cover and the fuel pump relay is the farthest one back toward the firwall and farthest towards the right side of the car.

I found the box like you said (you'd have to be blind not to notice it...) and there are 5 relays (all the same) under there...three on the engine side and two (space in the middle) on the driver/fender side.

I removed and replaced each one (one at a time) to eliminate the dreaded "pinitis" issue, but the battery is dead and my jumper cables are with a friend (Doh!) at this time...so as soon as my cables are returned, I'll see if it was a case of "pinitis" or not...

Just out of curiousity...what are the other relays for/related to?

Windshield
|--------|
| 1.x 2.x |
| 3.x . . . .|
| 4.x 5.x |
|--------|
Front of car

If I read your directions correctly, I've assumed that number 2 would be the fuel pump relay...correct?

(The "x" represents the relay itself...the numbers corrolate with the position.)

Again, thanks for you input and knowledge...both of you...

79Mercy · #6 07-01-2009, 12:00 AM

according to your diagram the fuel pump relay is 1.

Let me try again. The fuel pump relay the one closest to the firewall, and closest to the motor. Sorry my first message was a little cloudy.

I have no idea what the other relays are, I know one of them is for the aux fan and another for the AC/heater system.

mgburg · #7 07-04-2009, 10:00 AM

Quote:

Originally Posted by 79Mercy

according to your diagram the fuel pump relay is 1. ... Let me try again. The fuel pump relay the one closest to the firewall, and closest to the motor. Sorry my first message was a little cloudy. ... I have no idea what the other relays are, I know one of them is for the aux fan and another for the AC/heater system.

No problem...On another note concerning this query, I managed to located the number/name of the mechanic that worked on this vehicle for the PO...he provided me some diagrams concerning the underhood wiring of this particular model (year included)...

I'm going to use that information and your correction and see if I can get this back up and running before the end of next week (that's when I'm expecting the jumper cables back...).

After I get the diagrams "scanned" into the computer, I may post them in here to be available to other members...I was able to "cull" a few other pages from the manual before I returned it...the guy is really nice...even though he had about 2 cars to finish up, he was friendly as all get-out and even wanted me to follow him so he could keep talking about the MB-line and what great stuff they made/make...He owns/drives a 190E AMG (Not sure what year it was...). I was looking/drooling over the thing...he didn't say if he races it though...but dang! That thing looks fast just parked...it has this "You just wish..." look to it...

Oh well, some day in the not too distant future...maybe by the time I'm 55...in about 3 years or so...

I'll let you folks know what I find on the FP and relate TSing....

Thanks again!