Author Topic: 1 Second CSV Relay (Read 21517 times)

DavidBrough · « **on:** March 20, 2009, 18:57:16 »

I’ve just purchased the 1 second relay and harness but can’t seem to get it to work and wonder if anyone has any suggestions. I’ve identified the CSV relay as the centre one on the left hand inner wing by tracing the wiring, disconnecting it and doing a test with a lamp on the CSV at start up. I have then wired in the new relay, mounted it firmly and connected its earth wire but then the CSV won’t activate at all. The whole thing seems as though it should be straight forward and the harness only seems to fit one way so I’m at a bit of a loss. Is it possible to check the new relay in isolation to make sure it’s not faulty or am I doing something wrong. All suggestions gratefully received.

JamesL · « **Reply #1 on:** March 20, 2009, 19:20:01 »

I think I was talking to Paul at Classic Preservation about you today!

Can't help, sorry

DavidBrough · « **Reply #2 on:** March 20, 2009, 20:04:55 »

Quite possibly, I went to see him earlier in the year about having some work done, I was quite impressed with his set up and knowedge.

ja17 · « **Reply #3 on:** March 21, 2009, 02:18:29 »

Hello David,

At the last Pub, Bob Possel had a brand new relay he had purchased from Mercedes. It did not work. By all means check your relay!

Did you check your system before installation of the new relay?

DavidBrough · « **Reply #4 on:** March 21, 2009, 07:50:13 »

Hi Joe,

Yes, the system works without the relay wired in but not with. Do you know how I might check the new relay, I got mine from the local MB dealer yesterday and it cost £200 with the harness so I'll definitely be taking it back if its faulty.

DavidBrough · « **Reply #5 on:** March 21, 2009, 08:28:09 »

Photo omitted from previous post

ja17 · « **Reply #6 on:** March 21, 2009, 13:55:27 »

Hello David,

Check to make sure you are modifying the correct relay and circuit for the intake cold start valve first (CSV). You can jump the #30 wire to the #87 at the original relay plug to momentarily activate your CSV to verify this. If the injection pump solenoid activates instead, you are on the wrong relay.

ja17 · « **Reply #7 on:** March 21, 2009, 14:50:05 »

Hello David,

The contacts in the time relay look like they are silver coated contacts that can tarnish from age and may loose continuity.

Since the contacts are normally closed check the continuity between terminal #31 and terminal #85 on the time relay with an ohm meter or continuity tester. If the contacts in the time relay are ok you will have continuity between #31 and #85.

The relay can be opened up and the contacts polished with a piece of paper until continuity is restored.

If your relay is ok, we will need to check to see why it is not being activated.

DavidBrough · « **Reply #8 on:** March 21, 2009, 16:09:20 »

Thanks Joe, the new relay seems to check out OK as there is continuity between terminals 31 & 85 both on the relay and through the new harness. However, the new harness only has two connections whereas the standard connector has 4 as per my last photo. As such, when the new harness is plugged in between the old relay and connector two of the existing connections are not made so I think that's why nothing works with the new bits connected. Should it be like this or do I need to make a connection between all 4 existing relay terminals and the existing wiring.

Naj ✝︎ · « **Reply #9 on:** March 22, 2009, 11:01:53 »

David,

Why do you need to add this relay?

naj

DavidBrough · « **Reply #10 on:** March 22, 2009, 11:41:37 »

Hi Naj,

A good question and I have deliberated for some time due to the cost.

My car has always been quite good on the cold or hot start (better when hot) but a bit temperamental on warm starting with the worst point being about 1/3 hours after running. Whilst it has always started eventually it has been quite embarrassing at times. As a result I fitted an earth switch to the CSV thermostat about 2 years ago so I could activate it when necessary and it worked so well I thought that fitting the MB fire and forget upgrade might be a good idea. Not looking such a good purchase at the moment though.

bpossel · « **Reply #11 on:** March 22, 2009, 11:44:43 »

David,

I have heard that one could take off the cover of the original cold start relay and pry the contacts a bit further away in order to increase the time.... never tired this, curious if anyone else has...?
Bob

DavidBrough · « **Reply #12 on:** March 22, 2009, 13:49:36 »

I’ve been doing a bit more investigation and testing and have come up with the following.

The new two wire harness makes a connection between terminals 85 (W terminal on TTS) & 86 (ignition switch and G on TTS) of the existing set up but breaks connections 87 (start valve wire) & 30 (power from fuse 6) as the connector only has twp pins. As such I decided to make two extra pins to make the connections between terminals 87 & 30. This seemed to work as the set up now allows the standard operation of the CSV when cold but still does nothing when hot.

I had already tested for continuity between terminals 85 & 31 on the new relay as Joe said but then decided to check again including terminal 86. It seems that there is continuity between all three pins but I’m not sure if this is good or bad. I would like to test the new relay with a battery and light but am not sure how to do this, can anyone help.

DavidBrough · « **Reply #13 on:** April 02, 2009, 11:44:31 »

I still can't get my 1 second relay to work and wondered if anyone had any further ideas on fitting or checking the unit.

graphic66 · « **Reply #14 on:** April 02, 2009, 23:00:47 »

http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/relay.htm This explains the realays, not sure if this helps, but it sure has been informative for me. All those numbers and connections are now very easy for me to understand!

ja17 · « **Reply #15 on:** April 03, 2009, 04:19:19 »

Helllo David,

I have installed some of these modifications. There is very little documentation on the subject. Page 07-14/19 of the late BBB has some information but no wiring diagram. I have opened up a time switch to see the inernals and there is an adjustment screw for duration. It sounds like your time switch is ok but the wiring is not set up correctly yet. If you can describe the harness, wire colors, and wire locations at each ends, I think we can figure it out. I would like to document this subject better for " starting aid tour".

The BBB reads "Subsequent Installation of One-Second Time Switch"

"A one-second time switch may be installed subsequently to improve warm-up characteristics. The switch actuates the electric starting valve on the intake pipe for 1 second even when the cooling water temperature is above + 35 degreeC.
(1) Move relay backwards on support so that the time switch can be mounted.

( 2) Fit additional cable harness. To do so , remove coupling form main cable harness on relay and insert connection of additional cable harness. Fit coupling onto time switch and fasten ground cable to screw.

(3) Performance test. At cooling water temperature above =35 Deg. C the starting valve on the suction pipe must operate for 1 second."

Parts required : 1 time switch #001 545 1624 and additional calbe harness 108 540 1009

bpossel · « **Reply #16 on:** April 03, 2009, 10:05:13 »

Question...

Isn't an alternative to also open up the cold start relay and slightly separate the contacts in order to increase the time?

Thought I heard, read this a while ago..

Bob

DavidBrough · « **Reply #17 on:** April 03, 2009, 11:24:47 »

Thanks guys.

Graphic66, that's a great write up and I've printed it off for future reference

Joe, I will check the wiring/parts later and post further details and pictures

Bob, I think opening the contacts on the existing relay may just alter the duration not the temperature at which it operates.

ja17 · « **Reply #18 on:** April 03, 2009, 16:39:29 »

Hello David and Bob,

David is correct. Altering the contacts will only change the duration. The factory modification makes the intake starting solenoid work at higher temperatures for one second. Normally it is not activated at higher temperatures on this version.

DavidBrough · « **Reply #19 on:** April 03, 2009, 19:21:02 »

I’ve had another good look at the parts and wiring and can firstly confirm the parts purchased appear to be correct as they carry the numbers quoted by Joe.

OK so where to start, the existing relay is shown in Pic1 and is the one nearest the expansion tank, it has four terminals as follows:-

Terminal      Connection            Colours
30     Power from fuse 6         Black/Pink/Red
85   From TTS W terminal         Pink
86   Ignition to G on TTS         Pink/Blue & Black/Pink/Blue
87   Start valve connection      Black/Pink/White

This works fine and is confirmed by connecting a light to the CSV.

The new harness has a two wire connection between the 4 pin existing relay and the 3 pin new relay as shown in Pics 2 & 3 with the third new relay connection being an earth. The terminals are as follows:-

31   Earth   separate brown wire
85   To 85 on the existing relay via new harness
86   To 86 on the existing relay via new harness

In its normal state the new relay has continuity between all three connections in any combination. Is this correct?

The first issue seems to be that the new harness when placed between the existing relay and vehicle wiring only makes a connection between terminals 85 and 86 and it actually breaks existing connections 30 & 87. To get round this I added two extra terminal connections as Pic 4 and the overall connection is shown in Pics 5, 6 & 7 (posted separately).

When the new relay is connected with the harness as supplied the CSV fails to work at all and doubtless this is because connections 30 and 87 are not made. However, when connected using the modified four pin harness the CSV works as normal but the 1 second relay just doesn't work in any state. I'm sort of thinking that the new relay has failed but just cannot see how the system would work in its supplied state due the fact that it breaks connections 30 & 87 so am I doing something wrong?

I hope this all makes some sort of sense and would appreciate any advice I can get.

DavidBrough · « **Reply #20 on:** April 03, 2009, 19:22:10 »

Extra photos for previous post

Peter van Es · « **Reply #21 on:** April 03, 2009, 22:04:35 »

David,

I haven't read all your posts, and haven't drawn a wiring diagram, but the fact that in the last picture you posted (pic 7) the old and the new stacked connector are still connected to the old, faulty relay may be creating havoc. Have you tried it without the old relay in the circuit (i.e. just unhook the old and the new stacked connector from the old relay).

Otherwise, trace all the wires and draw the diagram, it should tell you if it's correct.

Testing a relay is VERY easy. Disconnect all of the relay completely. Connect an Ohm meter to pin 87 and 30 of the suspect relay (it should show infinite resistance), and then connect 12V across 85 and 86. The resistance on the Ohm meter should drop to 0 if the relay works.

Peter

ja17 · « **Reply #22 on:** April 04, 2009, 05:02:41 »

Hello David,

Here is some more information for the mix. Now we can try to digest it all!

DavidBrough · « **Reply #23 on:** April 04, 2009, 06:48:19 »

Thanks Joe I'll have a look and think about that.

Peter, The existing relay is OK and should stay in place to continue controlling cold starts, the new relay just jumps in and takes over when hot. One of my main issues is that interconnection in that it is only two pin so breaks two of the existing relay connections and it's that bit that makes me think this could never work as supplied.

DavidBrough · « **Reply #24 on:** April 04, 2009, 08:58:33 »

Well I seem to have some progress as I've now tested the new relay with assistance from Joe Peter and others and it sort of works. I connected a lamp from 85 to battery positive 31 to battery earth and the lamp lit. I then touched 86 to positive to energise the relay and the lamp went out. However it is taking about 15 seconds to relight when power is removed from terminal 86, should this not be 1 second? If so how should I clean/adjust it? I have taken the relay apart and can see a screw but don't want to touch anything without advice.

So, whilst the time may not be correct it seems the relay is working, the but the question on how it should be connected is still eluding me

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Author Topic: 1 Second CSV Relay (Read 21517 times)

DavidBrough

DavidBrough

DavidBrough

DavidBrough

DavidBrough

DavidBrough

bpossel

DavidBrough

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graphic66

bpossel

DavidBrough

DavidBrough

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DavidBrough

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