Mercedes bourton start problems

by monty2 Thu Sep 24, 2020 8:44 am

2017 Mercedes bourton batteries ok and on board charging ok. No problems until vehicle driven without stopping for approx. 3-4 hours then engine won't restart. A jump start gets it going and all is fine until another long trip. Any thoughts? the AA man thought it was the van habitation 12v system was draining the battery but my own thoughts suggest a vehicle ECU problem.

by BobK Thu Sep 24, 2020 8:59 am

Hi Monty, are you saying "it won't start" do you mean that the starter motor is not turning ? which I would presume is what you mean. Once it is "jump started" ....... if you switched it off, would it restart then? What would happen if you jump started and then drove for a further distance, would it start then? Interesting .. Did you jump start it from the under bonnet terminals or direct to the battery terminals.

by monty2 Thu Sep 24, 2020 10:46 am

Hi The starter motor seems to start and then a clicking noise as though battery is flat or immobiliser is activated. It was jump started direct from the battery terminals as per AA man's check of the battery. After starting the engine would restart on the starter even after a couple of days of short or no journeys. Problem if van was driven for 3-4 hours then it wouldn't restart. I thought that when the ECU does it's pre start checks it finds a fault and activates the immobiliser possibly an ABS fault? but no messages or fault code and why wait until after a long journey.

by Eltel Thu Sep 24, 2020 1:28 pm

I had a similar issue with a Fiat based motorhome..

Called out Green Flag and the jump started from the terminals under bonnet

Great Fixed

Stopped at Tesco for provisions, engine would not start.

Called Green Flag a second time, this engineer know of the previous call out went straight to the battery in the cab between the seats

Guess what the main Fiat Dealer had the battery disconnected and on completion did not tighten the leads on the battery terminal.

Fixed and I never had the problem again.

Not sure of the electrics on a Mercedes, but may be worth checking it out.

Terry

by PLOUGHLIN Thu Sep 24, 2020 2:11 pm

Eltel wrote:I had a similar issue with a Fiat based motorhome..

Called out Green Flag and the jump started from the terminals under bonnet

Great Fixed

Stopped at Tesco for provisions, engine would not start.

Called Green Flag a second time, this engineer know of the previous call out went straight to the battery in the cab between the seats

Guess what the main Fiat Dealer had the battery disconnected and on completion did not tighten the leads on the battery terminal.

Fixed and I never had the problem again.

Not sure of the electrics on a Mercedes, but may be worth checking it out.

Terry

I agree, remove the terminals and refix. Sprinters also have a known problem with what is called the Y cable, braided, which links the battery, starter and alternator, susceptible to corrosion and bad connections.

I had a similar problem sometime ago. https://www.autosleeper-ownersforum.com/t22646-mercedes-sluggish-starting

Foolishly I put it down to failing battery so replaced it with nice tight connections. Problem solved, but nearly 3 years on the failed battery sits in my garage still able to hold 12.6v for long periods. Tightening terminals would have been cheaper than replacement. hugegrins

by monty2 Thu Sep 24, 2020 2:19 pm

Many thanks it all looks clean and tight but I'll do as you suggest and check the Y cable.

by Tinwheeler Thu Sep 24, 2020 4:45 pm

We had a problem with a duff starter relay on our 2011 Sprinter. It was totally unpredictable. The relay made a clicking noise but the starter did not turn.

by RML Fri Sep 25, 2020 7:43 am

Did you measure the battery voltage before jump starting the engine?
Rich..

by inspiredron Fri Sep 25, 2020 8:52 am

Nobody has yet mentioned the earth strap from engine to chassis. Check that for security and corrosion as well. It's possible that the engine end bolt could expand enough when the block is hot to lessen the integrity of the contact. Jump start will by-pass the earth strap

. When the block cools it contracts and grips enough. It could also reduce charging current to both batteries when driving.

by BobK Fri Sep 25, 2020 9:22 am

Just back on to this thread, but my original queries yesterday were based on the thoughts of others since then, ... a bad earth; battery connection; starter terminal connection. up!

by monty2 Sat Sep 26, 2020 10:56 am

I've checked battery terminals all tight. I will check the engine earth if it ever stops raining. But battery has discharged whilst in my drive (no hook-up) no battery drain showing so maybe a duff battery cell. Thanks for all suggestions when un-quarantined I'll get battery checked together with the starter relay.

Mercedes bourton start problems

Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems

Re: Mercedes bourton start problems