Advice on modifying a modern.

[Steve P]

Opinions appreciated.

My daughter has an Astra J from 2011.It has what I think is a daft design of connection to the battery and all electrical systems, the positive battery terminal and two metal plates. See Image.

Intermittently but annoyingly she sometimes gets in and turns the key..no power or lights on the dash. The connection between the 2 metal plates and the battery is lost and I have to take them off and clean them before service is resumed. my plan is to remove the old battery clamp and the first plate and replace it with a pre-made 300 amp lead with a battery clamp on one end and an eyelet on the other to connect the fuses. What do the experts think?.

BTW this a very common fault on this model.

Steve

Edited December 14, 2023 by Steve P

[Gary Flinn]

Presumably the problem is that the bolted connections gets corroded and then provide a high resistance?

What your suggesting should work, alternatively, a short length of Copper Busbar as used in electrical panels (suitably rated) with new Brass bolts/nuts/washers would work too.

Do you know if the plates are steel or Copper coated with something?

Gary

[Steve P]

When I roughed them up with sandpaper they did appear copper coloured below the surface finish,it seems to be first bolt to the main bar that loses conductivity.

Also they are quite thin plates.

S

[JohnD]

Steve,

Dismantle and rough/clean the surfaces, as before.    Then grease them where they contact each other with a "conductive grease" ( https://www.amazon.co.uk/s?k=conductive+grease&adgrpid=52839051826&hvadid=259032990207&hvdev=c&hvlocphy=1006854&hvnetw=g&hvqmt=e&hvrand=13151397456398697064&hvtargid=kwd-306759865908&hydadcr=4398_1795150&tag=googhydr-21&ref=pd_sl_89mdcd6149_e ) Other suppliers are available.

Reassemble, and then grease over them with Vaseline.  Include the battery terminal.   That should provide the best protection and conduction that you can.

 

BUT!   That you need to do this repeatedly makes me wonder (I don't know the Astra) if the junction box is getting a lot of road spray.  Work out where it's coming from, and make up some sort of under bonnet deflector, to keep it away.   You might ask on an Astra Owners website if anyone else has this problem:  https://www.astraownersnetwork.co.uk/

John

 

 

Edited December 14, 2023 by JohnD

[Gary Flinn]

That sounds like they may be plated copper busbar and the plating is failing.

Some thicker copper busbar and M10 Brass Nuts/Bolts/Washers between the Battery clamp and the centre connection should make a good electrical connection, make sure the connection to the existing plate is cleaned up and all the bolts are tight, that should do it.

As John suggests you can get conductive grease but if all the connections are clean and tight, then you coat the bolt/busbar connection with Vaseline that should last.

Regards

Gary   

Edited December 14, 2023 by Gary Flinn

[trigolf]

Hmm...

If it was me, I would resist the temptation to replace some or all original bars with copper bus bar, although a good idea. I would just do as John suggests and 'clean' the connections and coat with conductive grease. If the car was involved in an insurance claim it's likely they would spot the unofficial mod and refuse to repair?

[Steve P]

The car has an issue where the radio cuts out now and again, probably due to a related issue with the fuses bolted to the bus bar.To me the first connection from the battery post is un-necessary.BTW that image is off the net not my car but it`s the same..

I am going to strip it all off and clean and grease as suggested.

I don`t think it gets any road spray, it`s in a plastic box with a cover anyway.

Steve

[Wagger]

Do as JohnD and Trigolf suggest because it looks to me that this has been designed as individual fuses, hence the plastic bits that stop those bits being cooled. My Ducato has a similar plate idea.

If you do use a busbar, then add fuses suitable for the individual wire sizes. It will be tedious and also prone to failure.

[PeteH]

Those "plastic looking" bits, are they not Fused links?. It look vaugely like 500A embossed on the first link?. If so, removing them removes a safety device, and is not a good idea. the material is likely thin simply in order to ensure the link does break in event of an overload?. The clean/coat advice is what you should follow. A lot of moderns have similar. SWMBO`s Nissan has "stop/start" and that is the same.

Pete

Edited December 15, 2023 by PeteH

[Colin Lindsay]

14 hours ago, Steve P said:

The car has an issue where the radio cuts out now and again, probably due to a related issue with the fuses bolted to the bus bar.

Same as my daughter's 2016 Fiesta. Every so often you have to disconnect the battery, wait for ten minutes, then reconnect (and retune the radio etc). I think it's one of the reasons why, as I get older, so too do my cars.

 

[Steve P]

4 hours ago, PeteH said:

Those "plastic looking" bits, are they not Fused links?.

Yes they are fused links, I won`t be removing those, It`s the first plate and the joint to the battery terminal which seems to be the one that fails. The dodgy connection is probably why the radio cuts out so If I remove and clean the fuse links I hope that will fix that. As I said the fault is very common with these models.

I guess like Triumphs they were designed to last a certain period before you buy another car. I`ve never been like that and keep them until they die.

S

[Wagger]

If you are keeping the car, you could fit your own fuse box if you can find fuses with the ratings required. Make your own and bolt it out of the weather. On my Ducato, I have added another wire to the battery terminal and fitted an auxilliary fuse for the solar charging system and 2nd inverter.

Just as with my Ducato, it is asking a lot to expect a battery clamp and a relatively skinny bolt to handle 500+ amps without heating up, and any vibration will loosen it.

Whoever designed it is not a very good Engineer.

Edited December 15, 2023 by Wagger

[SpitFire6]

HI,

No,.grease will not be "non-conducive" in this application. Synthetic, mineral, vegetable or animal will have little influence.
 

I do not recommend any of the "Conductive greases". Conductive grease is good for antistatic applications.
I recommend AFC50 grease. Cheap OEM dielectric grease is also perfect for this application if no corrosion is present.

Cheers,
Iain