E-Class (W124) 1984-1995: E 260, E 300, E 320, E 420, E 500 (Includes CE, T, TD models)

Apexi RSM

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Apr 17, 2007 | 01:44 AM
  #1  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
Apexi RSM

Hey guys, not really enjoying seeing the speedo needle bump up and down at low speeds and moderate to high speeds so i've got the opportunity to pick up an RSM which is a rev speed meter, i just need to know whether i can install it on my 89' 260E. Is it doable? here's a pic of the actual product including the wiring harness.




thanks in advance
Reply
Old Apr 17, 2007 | 01:55 AM
  #2  
CDP's Avatar
CDP
MBWorld Fanatic!
 
Joined: Oct 2004
Posts: 5,816
Likes: 0
From: Orange County, CA
W124's
Anything is doable with the right person to install it.

A couple of my friends have ApexI products installed in their cars and I love what they have to offer. This would be perfect to mount in the center of the instrument cluster.

Is that their new design? I like the older models better...
Reply
Old Apr 17, 2007 | 02:04 AM
  #3  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
that is actually the series 1, so the older model i like it for its simplicity and the colour matches the older style of w124, i was thinking mounting on the steering wheel collumn, so i would view it through th esterring wheel.., so this would get wired up to the ecu? anyways ill try and get a electrical technician to sus it out
Reply
Old Apr 17, 2007 | 09:41 AM
  #4  
myfirstbenz's Avatar
MBWorld Fanatic!
 
Joined: Jun 2005
Posts: 1,467
Likes: 0
From: San Diego Californ-i-a
89 300TE, and 68 280sel
Originally Posted by kiasu
that is actually the series 1, so the older model i like it for its simplicity and the colour matches the older style of w124, i was thinking mounting on the steering wheel collumn, so i would view it through th esterring wheel.., so this would get wired up to the ecu? anyways ill try and get a electrical technician to sus it out
why not just have your speedo repaired?
Reply
Old Apr 17, 2007 | 10:34 AM
  #5  
bicylindrico's Avatar
Senior Member
Photoriffic
Shutterbug
Liked
Loved
 
Joined: Apr 2007
Posts: 351
Likes: 90
It's just the cable.
Reply
Old Apr 18, 2007 | 12:43 AM
  #6  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
i thought it was a common thing with all 124s.., besides im still going to be using this unit for other features once i get a hybrid motor in
Reply
Old Apr 18, 2007 | 09:14 AM
  #7  
shdoug's Avatar
MBWorld Fanatic!
15 Year Member
Liked
 
Joined: Dec 2006
Posts: 1,042
Likes: 1
From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
Mine does that,too. Are we in agreement that it's just the cable? Will it get worse?
Reply
Old Apr 18, 2007 | 10:47 AM
  #8  
myfirstbenz's Avatar
MBWorld Fanatic!
 
Joined: Jun 2005
Posts: 1,467
Likes: 0
From: San Diego Californ-i-a
89 300TE, and 68 280sel
Originally Posted by kiasu
i thought it was a common thing with all 124s.., besides im still going to be using this unit for other features once i get a hybrid motor in
Hybrid motor? Do explain
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-1

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-2

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-3

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-4

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-5

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-6

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-7

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-8

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
story-9

Mercedes Teases Updated EQS With Steer-By-Wire and a Yoke

 Verdad Gallardo
Old Apr 18, 2007 | 01:07 PM
  #9  
Bigpete123's Avatar
MBWorld Fanatic!
 
Joined: Feb 2006
Posts: 1,325
Likes: 2
From: Seattle
1990 300ce
This seems like a great length to go to just to get rid of that. My car doesn't do that at all... so I would think there's something wrong with your speedo/etc.

It just seems like overkill to me.
Reply
Old Apr 18, 2007 | 01:32 PM
  #10  
lkchris's Avatar
MBWorld Fanatic!
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Sep 2005
Posts: 6,189
Likes: 241
From: Albuquerque
'10 CL550, '12 GL550
Yer gonna need to fix yer cable anyway, because the bouncing speed reading affects yer cruise control.
Reply
Old Apr 18, 2007 | 01:56 PM
  #11  
Gasdrinker's Avatar
Junior Member
 
Joined: Feb 2007
Posts: 48
Likes: 0
R230 W124 W212
haha, my car has the same problem from 30-40, and yes my cruise control is also fubar, I have replaced the cable about 3 years ago and the problem just recently came back...
Reply
Old Apr 18, 2007 | 11:36 PM
  #12  
bicylindrico's Avatar
Senior Member
Photoriffic
Shutterbug
Liked
Loved
 
Joined: Apr 2007
Posts: 351
Likes: 90
The cable casing can be distorted by pulling on the cluster without detaching the cable at the transmission. Instant bounce.
Reply
Old Apr 19, 2007 | 01:06 AM
  #13  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
bicylindrico: that could be the problem as i had my cluster repaired due to kms not ticking over anymore, but has since been fixed..could it be careless workmanship? i mean i will get this speedo cable thing fixed and get the cruise control working normally instead of just full gassing it when i set the speed..haha

but nevertheless i still need to know if i can get this wired up to the comp and sensors, theres abosolutely no writeup or history of anyone ever installing this product on the net..

myfirstbenz: 2jz-gte vvti w/ 6 speed box , should be fun
Reply
Old Apr 19, 2007 | 12:46 PM
  #14  
myfirstbenz's Avatar
MBWorld Fanatic!
 
Joined: Jun 2005
Posts: 1,467
Likes: 0
From: San Diego Californ-i-a
89 300TE, and 68 280sel
Originally Posted by kiasu
bicylindrico: that could be the problem as i had my cluster repaired due to kms not ticking over anymore, but has since been fixed..could it be careless workmanship? i mean i will get this speedo cable thing fixed and get the cruise control working normally instead of just full gassing it when i set the speed..haha

but nevertheless i still need to know if i can get this wired up to the comp and sensors, theres abosolutely no writeup or history of anyone ever installing this product on the net..

myfirstbenz: 2jz-gte vvti w/ 6 speed box , should be fun
I saw that done on a late 70's SLC. I would personally have a hard time with putting a jap motor in a Benz, but hey, it's a great motor for sure. Keep us updated with photos!
Reply
Old Apr 20, 2007 | 12:38 AM
  #15  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
so is this doable....wiring shouldnt be a problem?, im just unsure about the type of bosch computer on the w124s..i know what they look like which is the scary part, well i think i may just go ahead and purchase it
Reply
Old May 29, 2007 | 09:49 AM
  #16  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
hey guys i've acquired the rsm, and have all installation instructions for it but it mentioned that it wont work for cars other than jap's, but ive heard of people installing these in their audi's. how are the computers on these 124's can they be wired up to a harness? are the speed sensors wired? or a mechanical cable..etc plz help
Reply
Old May 29, 2007 | 03:56 PM
  #17  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by kiasu
hey guys i've acquired the rsm, and have all installation instructions for it but it mentioned that it wont work for cars other than jap's, but ive heard of people installing these in their audi's. how are the computers on these 124's can they be wired up to a harness? are the speed sensors wired? or a mechanical cable..etc plz help
If you have an 89 260E, there isn't much in the way of electronics !!!!
You can pick up the engine speed signal with the green/yellow wire that runs from the EZL unit (electronics ) to the diagnostic socket, then to the OVP relay, fuel pump relay, then the tach.

The speedometer is cable driven, but there is a hall effect speed sensor mounted on the back of the speedo.
The sensor has a brown earth wire, the yellow/green engine speed wire and a third wire (color?) that runs to the fuse box then to the ignition switch.

What is the wiring diagram of the unit that you are trying to install?
Reply
Old May 29, 2007 | 11:02 PM
  #18  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
hey thanks for the reply i scanned some documents which may be relevant.

http://img.photobucket.com/albums/v6...u/scan0003.jpg
http://img.photobucket.com/albums/v6...u/scan0002.jpg
http://img.photobucket.com/albums/v6...u/scan0001.jpg
Reply
Old May 29, 2007 | 11:04 PM
  #19  
Garfunkle_W124's Avatar
Super Member
 
Joined: Feb 2007
Posts: 941
Likes: 0
From: Atlanta
1995 S14
where did you order this?
Reply
Old May 30, 2007 | 12:19 AM
  #20  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Look at your basic Apexi connection diagram.
You need ignition power, constant power, rpm signal, ground, vehicle speed signal.
The Apexi colors I'll indicate first, followed by the Mercedes color to connect to.
Red to Red/Pink ( ignition power)
Orange to Red ( constant power)
Yellow to Green/Yellow ( RPM signal)
Black to Brown (ground)
Purple to ???? (vehicle speed signal)
Only place that has any kind of a vehicle speed signal is the cruise control, which picks up the signal from a hall effect sensor on the back of the speedometer. This is also the Green/Yellow wire so you may try jumpering together the Yellow and purple wires on the Apexi and connect to green/yellow, but not sure !
All of the wires you need can be found at the fuel pump relay.

Possible problem is if the hall effect sensor is not outputting correctly due to your mechanical speedometer not functioning properly.

Still not sure if it will work, as you're dealing with a very unsophisticated car in the 260E.

Last edited by RBYCC; May 30, 2007 at 12:23 AM.
Reply
Old May 30, 2007 | 01:22 AM
  #21  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
so your saying to connect this unit to the fuel pump relay and the cruise control module? thats sounds so tricky, but ill inform the auto elec about it, thanks for the info, so the fuel pump relay is still in the engine bay or towards the rear of the car..
Reply
Old May 30, 2007 | 07:37 AM
  #22  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by kiasu
so your saying to connect this unit to the fuel pump relay and the cruise control module? thats sounds so tricky, but ill inform the auto elec about it, thanks for the info, so the fuel pump relay is still in the engine bay or towards the rear of the car..
Reason I state the fuel pump relay is that all the wires you need are located there.
Easy to make a temporary trial connection at one convenient point, then to find wires all over the car !
Reply
Old May 30, 2007 | 10:59 AM
  #23  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
oh i understand, but is the fuel pump relay located with the fuel pump or near a fuse box in the engine bay
Reply
Old May 30, 2007 | 11:00 AM
  #24  
kiasu's Avatar
Thread Starter
Almost a Member!
 
Joined: Feb 2007
Posts: 68
Likes: 0
From: Australia
260E
where did you order this?
i bought it interstate in australia from one of the jap boys from firesport.com
Reply
Old May 30, 2007 | 11:57 AM
  #25  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by kiasu
oh i understand, but is the fuel pump relay located with the fuel pump or near a fuse box in the engine bay
Fuel pump relay should be next to the OVP relay and is located behind the battery. Should have about eight terminals and the OVP has about seven with two fuses mounted on top.
All the wires that you need can be accessed at this point.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 09:42 PM.

story-0
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-1
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-2
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-3
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-4
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-5
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-6
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-7
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-8
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE
story-9
Mercedes Teases Updated EQS With Steer-By-Wire and a Yoke

Slideshow: The 2027 update adds a fully digital steering system, revised styling, and potential charging upgrades as the company looks to revive interest in the luxury EV.

By Verdad Gallardo | 2026-04-04 10:24:38


VIEW MORE