Split charging relay question

[Califan61]

Thanks for the reply. They are my accessories, I moved them from the battery + post. You can see the battery monitor to the right of the battery. Its just a neater way to wire in those low current device.

 

[sidepod]

Ok so humour me here. Let’s go back to the root of the problem.

Are your leisure batteries NOT charging whilst driving?

You stated that, when on EHU , the split charge relay closes and you have voltage on both terminals of the SCR?
Under this condition (engine off/EHU in) what voltage do you have at the SCR terminals?

What voltage do you have at the SB?

 

[Califan61]

Ok so humour me here. Let’s go back to the root of the problem.

Are your leisure batteries NOT charging whilst driving?

You stated that, when on EHU , the split charge relay closes and you have voltage on both terminals of the SCR?
Under this condition (engine off/EHU in) what voltage do you have at the SCR terminals?

What voltage do you have at the SB?

Thanks for the reply and appreciate the help.

Are your leisure batteries NOT charging whilst driving?

I have only noticed the LBs not charging from altenator recently. I am sure this had worked previousily but havent recently camped were I needed full batteries. They appear to charge OK on hook up so again didnt think much of it.

In another thread my intial issue was no volts at SB side of SCR with no engine running or ehu on when putting a voltmeter from there to earth as i wanted a cleaner method to keep the starter topped up in storage. So brought a Vanbitz Battery Master as I have never had any EHU charging to starter battery which i just accepted. Prior to fitting, i tested the volts from the SCR and that is where the problem started. I beleive I should be seeing the SB voltage?


You stated that, when on EHU , the split charge relay closes and you have voltage on both terminals of the SCR?
Under this condition (engine off/EHU in) what voltage do you have at the SCR terminals?

Yes i have voltage at both terminals while on EHU at the SCR but think i was reading the LB passing through it, not the voltage from the SB.
The voltage at the SCR while on EHU is 13.57v for LB side and the same for the SB side. The SCR was slightly warm. Direct reading from front LB 13 57v. At the dame time I checked the reading at the SB posts 12.55v.

With the engine running and no max charge selected I have got 13.42v at the SB terminals and 15.0v with max charge on.


What voltage do you have at the SB?

The SB voltage this morning is 12.74v after a drive out yesterday. LB on display was 12.0v with a 1 amp draw with max charge on yesterday.

I dont know if these two are connected or is it the same issue?

 

[sidepod]

Ok, back to first principles.

Do a continuity check between the SB side of the SCR and the SB.

Engine off/No EHU

Set your multi meter to Continuity so it makes a buzz when you touch the leads together.

Connect one lead to the SCR SB terminal and , with the other lead touch any/all of the cables at the SB until it buzzes. This will be your link.

It has to be there somewhere!!!

If/when you find it you could double check it by disconnecting the link at both ends and repeat the continuity test. This will rule out any possible parallel paths.

 

[Califan61]

Ok, back to first principles.

Do a continuity check between the SB side of the SCR and the SB.

Engine off/No EHU

Set your multi meter to Continuity so it makes a buzz when you touch the leads together.

Connect one lead to the SCR SB terminal and , with the other lead touch any/all of the cables at the SB until it buzzes. This will be your link.

It has to be there somewhere!!!

If/when you find it you could double check it by disconnecting the link at both ends and repeat the continuity test. This will rule out any possible parallel paths.

I did do most of that at the weekend but like you say I need to go back to basics. I had a thought that my cali has been at the dealers four times with bellow replacement and dashboard issues and wonder if they may have not reconnected that no 2 cable. Im using the van this week so dont have the time to do the proper checks but will post once I am have some answers.
BTW, i have registered with Erwin, it mentions printing information, are I able to download PDFs or do I need to be connected to a printer?

Thanks for your guidance.

 

[sidepod]

I did do most of that at the weekend but like you say I need to go back to basics. I had a thought that my cali has been at the dealers four times with bellow replacement and dashboard issues and wonder if they may have not reconnected that no 2 cable. Im using the van this week so dont have the time to do the proper checks but will post once I am have some answers.
BTW, i have registered with Erwin, it mentions printing information, are I able to download PDFs or do I need to be connected to a printer?

Thanks for your guidance.

If you want to download, select the print icon and it’ll prepare and open a PDF. Once open just Save to File and it’ll save it.

 

[Califan61]

If you want to download, select the print icon and it’ll prepare and open a PDF. Once open just Save to File and it’ll save it.

Thanks.

Had a chance to have a look around the battery this evening. Look what I found!

Cable 2! which is the one at the SCR terminal I assume and explains why I have had no continuity there.

The dealer must have disconnected it when it was in previousily and i havent needed to use altenator battery charging.

It was tucked upwards so didnt look out of place. So hopefully this will solve the mystery but will report back once I have reconnected it.

 

[Califan61]

Thanks.

Had a chance to have a look around the battery this evening. Look what I found!

Cable 2! which is the one at the SCR terminal I assume and explains why I have had no continuity there.

The dealer must have disconnected it when it was in previousily and i havent needed to use altenator battery charging.

It was tucked upwards so didnt look out of place. So hopefully this will solve the mystery but will report back once I have reconnected it.

View attachment 142101

Further to this I tested the cable 2 and it did go back to the SCR. So I wasnt going mad! I connected it up to the battery top fuse box and normal service has resumed. Engine running 50a and 70a with max charge shown on panel. Phew!!

Before i fit the Vanbitz battery master I will charge the LBs and see if anything is going into the starter battery from the EHU. I can see the SCR is live while on EHU charging so maybe that will function too.

 

[sidepod]

Back of the net!!! Well done

 

[Califan61]

Back of the net!!! Well done

Thanks for the help @sidepod, it really had me stumped but your guidance and images were really helpful.

 

[vbk1975]

Further to this I tested the cable 2 and it did go back to the SCR. So I wasnt going mad! I connected it up to the battery top fuse box and normal service has resumed. Engine running 50a and 70a with max charge shown on panel. Phew!!

Before i fit the Vanbitz battery master I will charge the LBs and see if anything is going into the starter battery from the EHU. I can see the SCR is live while on EHU charging so maybe that will function too.

Great news, although if that cable was live, which it may well have been during driving then that is really poor regardless and perhaps not dangerous, but certainly not without consequences.

I would just ensure the cable is bolted down to the correct torque, these high current bolt down fuses clearly flow a lot of current and also are subject to heat and vibration cycles esp. in the engine bay. If they get at all loose they can become incredibly hot and the fuse doesn't protect for high resistance.

Well done!

A

 

[Califan61]

Great news, although if that cable was live, which it may well have been during driving then that is really poor regardless and perhaps not dangerous, but certainly not without consequences.

I would just ensure the cable is bolted down to the correct torque, these high current bolt down fuses clearly flow a lot of current and also are subject to heat and vibration cycles esp. in the engine bay. If they get at all loose they can become incredibly hot and the fuse doesn't protect for high resistance.

Well done!

A

All good points, thank you. I will raise with the dealership why it hadnt been reconnected. My guess is during the dashboard speedo issue they gained access to the fuse box under the battery. They clearly didn't test the circuits they disconnected. The wire would have been live during charging on EHU and with the engine running when the SCR was closed.