voltage drop

An alchemy of sparks, copper wire and earth

Moderators: User administrators, Moderators

User avatar
ghost123uk
Registered user
Posts: 6855
Joined: 10 Mar 2006, 10:15
80-90 Mem No: 2585
Location: John in Malpas, in the very S. W. part of Cheshire.
Contact:

Re: voltage drop

Post by ghost123uk »

There is nowt wrong with those chargers. If they are showing that they have entered a charging phase (LEDs or summat) then they have "kicked in". It's only a very flat battery that causes them to not "kick in".
Got a new van, but it's a 165bhp T4 [shock horror] Accurate LPG Station map here

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

I should clean my contacts and wire ends with this method:
https://www.youtube.com/watch?v=xkw_52rFHU8" onclick="window.open(this.href);return false;

Living in the city centre (and being 15 min walk away from the parking lot where the van is) is not the best doing this kind of gadgeteering. :x
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

Tried that salt ans vinegar method in the video on one of my spare harnesses. Impressive results:

turned this:
Image

into this:
Image

and this:
Image

into this:
Image
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

User avatar
Oldiebut goodie
Registered user
Posts: 7488
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: voltage drop

Post by Oldiebut goodie »

That is only cosmetic cleaning - the corrosion to be concerned about is inside the crimped area which cannot be cleaned easily. New terminal is the only cure. Even hot flux inside cannot be guaranteed to be be efficacious in every case. (With apologies to The Scaffold and Roger McGough)
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

Today I had a call from the rebuilders. My girlfriends father (who works there) told me that the rotor was burnt and that caused the fault of the regulator. The rear bearing housing was also damaged. Now they are gathering parts and in a few days I will get a repaired alternator.

Yesterday I got my batteries home. The brand new starter was at 12.54V which is about it was when I got home without the alternator. I've put on the charger in the evening and in the morning the charger indicated full (green LED on Lidl charger) About 1.5 hours after I read 13.40V
The leisure was at 13.05V and I am charging it since 9'o clock.


Oldiebut goodie wrote:That is only cosmetic cleaning - the corrosion to be concerned about is inside the crimped area which cannot be cleaned easily. New terminal is the only cure. Even hot flux inside cannot be guaranteed to be be efficacious in every case. (With apologies to The Scaffold and Roger McGough)

Then cut old terminal, deoxidate the wire with the electrolyte, crimp on new terminal and solder it? That is better?
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

User avatar
Oldiebut goodie
Registered user
Posts: 7488
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: voltage drop

Post by Oldiebut goodie »

Yes - I prefer to solder as this prevents the corrosion developing in that crimp. Use shrink tubing also as this gives support to the solder/cable joint, preferably adhesive lined stuff if you have it. If the wire is black just rub flux into it with your fingers and it will soon clean it. (I usually ditch that wire though as if the corrosion has wicked up inside it will never get any better and could cause problems in the future)
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

User avatar
CovKid
Trader
Posts: 8411
Joined: 30 Apr 2006, 13:19
80-90 Mem No: 3529
Location: Ralph - Coventry (Retired)
Contact:

Re: voltage drop

Post by CovKid »

Anything exposed to the elements gets soldered and shrink wrapped on mine. I'd use vinegar on terminals plugged to earth crown though as its generally the spade part that causes all the problems. I have a new earth point to go in over the Summer though. Was never keen on what VW fitted.
Roller paint your camper at home: http://roller.epizy.com/55554/" onclick="window.open(this.href);return false; for MP4 download.

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

OK!

I charged the leisure for 24 hours with the Lidl charger. The green light didn't came on, so I took it off the charger. After an hour rest I've read 13.30V. After 2 hours the reading was 13.20V
I think that battery is not in its best shape...
I will measure it a few hours later

May I try to charge it further?
Could this caused the alternator fail?

Update: after 4 hours the voltage dropped to 13.10V
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

User avatar
ghost123uk
Registered user
Posts: 6855
Joined: 10 Mar 2006, 10:15
80-90 Mem No: 2585
Location: John in Malpas, in the very S. W. part of Cheshire.
Contact:

Re: voltage drop

Post by ghost123uk »

I would double check those readings with another meter. I haven't heard of a battery "holding" a voltage as high as that after a rest. 12.9 Volts is normal.
Got a new van, but it's a 165bhp T4 [shock horror] Accurate LPG Station map here

Smcknighty
Registered user
Posts: 998
Joined: 24 Jul 2012, 20:40
80-90 Mem No: 14436
Location: West Sussex

Re: voltage drop

Post by Smcknighty »

Covkid what earth point are you putting in out of interest? A bolt type thing or have you managed to find a replacement for the spades one?

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

ghost123uk wrote:I would double check those readings with another meter. I haven't heard of a battery "holding" a voltage as high as that after a rest. 12.9 Volts is normal.

OK! I have only a cheap LED digital voltmeter from Ebay now ( like this: http://www.ebay.com/itm/LCD-DC-3-2-30V- ... SwpDdVP1YZ" onclick="window.open(this.href);return false; ) that reads 13.0V
Checked some other DC sources with both and looks like the multimeter reads around 0.2V higher

I've just ordered a new multimeter with a clamp style ampermeter and will borrow my brothers professional multimeter.
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

User avatar
syncroandy
Trader
Posts: 1905
Joined: 18 Oct 2005, 18:15
80-90 Mem No: 851
Location: North Lancs. UK
Contact:

Re: voltage drop

Post by syncroandy »

Re. earths for the front lights or any other significant current-consumers, I recommend ring terminals:

Image
Syncrosport (taking a break as of summer 2024)
Volkswagen Transporter, reloaded.

252 GC5 EJ25 AAN L90D

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

syncroandy wrote:Re. earths for the front lights or any other significant current-consumers, I recommend ring terminals:
[/img]
Just was thinking about that especially for the cooler vent and the headlamps.

And managed a small load test on my leisure battery. I plugged on my 12V 30W soldering iron. After 1 min the voltage dropped to 12.70V measured with the multimeter and 12.5V measured with the voltmeter. After another minute it dropped to 12.60/12.4V
After disconnecting the soldering iron the voltage rised to 12.80/12.6V

After that I plugged the soldering iron on for 10 mins and watched the voltage. in 4 mins it dropped to 12.52/12.3V and raised 12.60/12.4V in the last minute. After disconnecting the solderer the voltage raised to 12.78/12.5V
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

User avatar
CovKid
Trader
Posts: 8411
Joined: 30 Apr 2006, 13:19
80-90 Mem No: 3529
Location: Ralph - Coventry (Retired)
Contact:

Re: voltage drop

Post by CovKid »

One from starter body to vehicle. Helps reduce gearbox nose corrosion.

Smcknighty wrote:Covkid what earth point are you putting in out of interest? A bolt type thing or have you managed to find a replacement for the spades one?
Roller paint your camper at home: http://roller.epizy.com/55554/" onclick="window.open(this.href);return false; for MP4 download.

User avatar
ZsZ
Registered user
Posts: 1543
Joined: 12 Feb 2009, 16:28
80-90 Mem No: 14899
Location: Budapest, Hungary
Contact:

Re: voltage drop

Post by ZsZ »

OK, I had time in the last few days so I think I solved my voltage problems.
I cleaned and soldered some wires, removed the aftermarket trailer turn signal converter and rewired the turn signal system as the factory setup.

On the positive side: cleaned and soldered the battery to starter, the battery to junction box and the junction box to fusebox cables.
On the negative side I cleaned the battery to engine cable, cleaned and soldered the gearbox to body cable, and cleaned the ground posts and connectors behind the fusebox.

Now I have 14,48V at the battery, 14,47V at the P post of the fusebox, 14,40V at the radio connector. and 0,5V drop when I switch the heater fan or the headlights or the front cooler vent.

some pics:
Starter cable starter side:
Image
now re crimped and soldered

GB to body ground:
Image

after the vinegar-salt treatment:
Image

soldered:
Image
Last edited by ZsZ on 21 Jan 2016, 16:46, edited 1 time in total.
Zoltan
1986 Multivan ex-Caravelle. Van since 2006, running mTDi 1Z since 2008 with Fiat Croma 1.9 TDid pump 2008-2019, custom pump since 2019
5spd custom box 4.57 diff + 0.74 5th

Post Reply