Relay & fuse

Midlifecrisis999

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Got the Check Engine Light on the dashboard and took my SL350 in for a diagnostic.

They found many faults - unsurpringly. However they also diagnosed a secondary air pump failure.

I brought the car away and did some research, located the correct relay and fuse locations under the bonnet and guess what? They had disappeared. I have a gaps instead of a relay and fuse. Me thinks - they were squirrelled away at the garage!!

So I need to replace them before I do anything. Any ideas on where to get a new relay and fuse?
 

alexanderfoti

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Erm, MB would be the best bet, but why not ask the garage for them back?
 
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Midlifecrisis999

Midlifecrisis999

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Am assuming that they are defunct parts, so need replacing. Worth a short before I commit myself to a secondary air pump replacement.

Thanks for the advice. I’ll head to the main dealer tomorrow
 

Wearsafoxhat

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I’d be heading back to the garage for a chat.
You should have spare fuses and perhaps can swap relays if you have two the same, eg one from the rear heated window or one used for an auxiliary item.



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Midlifecrisis999

Midlifecrisis999

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6E1D27CE-2268-4954-B23A-DD06A2C7DB3C.jpeg 14A6CF9E-C0BE-401C-A910-FFB2EC67EB1F.jpeg The puzzle continues.

I consulted my fuse chart found in the boot of the car. Unfortunately, it doesn’t seem to have the secondary air pump fuse on it. Very strange.

Have consulted some other fuse & relay charts and they are telling me that the secondary air pump relay & fuse should be N and f31.


My vehicle hasn’t got a Relay in N but has got one in M and it hasn’t got a fuse in f31 but in f32.

So I swapped then from M to N and f32 to f31 which resulted in the car not turning over. So I have put them back to f32 and M. So I back where I started and no further forward. Any ideas?

Here is a copy of my fuse chart and a picture of the fuse box.
 

Wighty

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View attachment 46775 View attachment 46774 The puzzle continues.

I consulted my fuse chart found in the boot of the car. Unfortunately, it doesn’t seem to have the secondary air pump fuse on it. Very strange.

Have consulted some other fuse & relay charts and they are telling me that the secondary air pump relay & fuse should be N and f31.


My vehicle hasn’t got a Relay in N but has got one in M and it hasn’t got a fuse in f31 but in f32.

So I swapped then from M to N and f32 to f31 which resulted in the car not turning over. So I have put them back to f32 and M. So I back where I started and no further forward. Any ideas?

Here is a copy of my fuse chart and a picture of the fuse box.
What did the garage say ? Did they remove any fuses
 
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Midlifecrisis999

Midlifecrisis999

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I haven’t revisited the garage. Thought I would do the research first. I have assumed they had removed the fuse and the relay based on the information posted by other members with the same issue.

But it does seem that some secondary air pump relays and fuses are in different places for R230 versions. It’s all very confusing and I still have no clear idea where the relay or fuse are for my version.
 
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Midlifecrisis999

Midlifecrisis999

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The next step - have now put a new fuse in f31. And left the relay in situ for the time being. I’ll check tomorrow morning after a cold start if the air pump starts up or not.

If anyone knows which is the correct hole for the relay then do let me know. I suspect it is either N, M or O.

The model is sl350 facelift 2006 version.
 

TerryQ

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Just out of interest what was the conclusion?
 

Steve@Avantgarde

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Most secondary air pumps are powered and relayed by the front SAM.

Its an easy test, check for 12v at the secondary air pump and a good earth. If you suspect the pump you can give it 12v to see if it runs, or actuate it with STAR, If that is ok, check the wiring from the SAM to the pump. I have had a few front SAM failures effecting the air pump.
 
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Midlifecrisis999

Midlifecrisis999

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Have given up trying to sort it out and booked it in for diagnostic and repair.
 

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