Running battery voltage

Please restrict your questions and replies to Capri related technical issues!
Owent2005
Posts: 72
Joined: Fri Nov 29, 2019 10:14 pm
Car(s): Ford Capri 1983 Mk3 1.6LS

Running battery voltage

Post by Owent2005 » Fri May 15, 2020 12:03 pm

Afternoon,

The eletrickery games continue. Quite a lot of the electrics in and around the dash stopped working after a period of four months when the car wasn't being used, rev counter, fuel gauge, eng temp etc. I thought I would trace each one to find each issue however when I flash main beam the volt meter gauge on the dash dips considerably so I checked the battery voltage. With the car running it was sat at 12.41 volts, am I right in thinking it should be sat around the 14v mark? Should I be looking at alternator issues or maybe take it for a long drive and see how it gets on?

TIA,

Owen

User avatar
stevemarl
Donator
Donator
Posts: 4421
Joined: Wed Jul 11, 2012 6:31 pm
Car(s): Capri 1.6 laser

Re: Running battery voltage

Post by stevemarl » Fri May 15, 2020 12:30 pm

Owent2005 wrote:
Fri May 15, 2020 12:03 pm
am I right in thinking it should be sat around the 14v mark?
Yep, the Bosch reg. is 14v, IIRC Lucas is 14.4, so your 12.4 suggests it`s not charging properly.
You`re aware the tacho, fuel & temp gauges all have their own 5v regulator on the cluster PCB? This is most likely reason for all 3 to stop.

Owent2005
Posts: 72
Joined: Fri Nov 29, 2019 10:14 pm
Car(s): Ford Capri 1983 Mk3 1.6LS

Re: Running battery voltage

Post by Owent2005 » Fri May 15, 2020 1:33 pm

Thanks for your kelp today Steve,
I kinda thought they must have been linked somehow, however I’m not sure what or where the 5v regulator is. I’m new to the game so not sure what the PCB is!

Any pointers will be greatly appreciated,

Owen

User avatar
Peter-S
Donator
Donator
Posts: 6887
Joined: Mon Jul 28, 2008 7:57 am
Car(s): 1985 Capri 2.0
1983 Capri 2.8i
Location: Kent
Contact:

Re: Running battery voltage

Post by Peter-S » Fri May 15, 2020 1:39 pm

Owent2005 wrote:
Fri May 15, 2020 1:33 pm
Thanks for your kelp today Steve,
I kinda thought they must have been linked somehow, however I’m not sure what or where the 5v regulator is. I’m new to the game so not sure what the PCB is!

Any pointers will be greatly appreciated,

Owen
The regulator is a little box thing on the back of the speedo cluster
ImageBanner by Peter Smith, on Flickr

User avatar
stevemarl
Donator
Donator
Posts: 4421
Joined: Wed Jul 11, 2012 6:31 pm
Car(s): Capri 1.6 laser

Re: Running battery voltage

Post by stevemarl » Fri May 15, 2020 2:00 pm

As Peter says, it`s on the back of the instrument cluster. All connections to instruments, warning lights, display bulbs etc are carried on a flexible Printed Circuit Board (PCB) as in pic. There is a central rectangular multi comnector in the centre through which all external connections are made . Instrument reg is black box/ heatsink assembly in top RH corner.
Image

User avatar
stevemarl
Donator
Donator
Posts: 4421
Joined: Wed Jul 11, 2012 6:31 pm
Car(s): Capri 1.6 laser

Re: Running battery voltage

Post by stevemarl » Fri May 15, 2020 6:02 pm

Re. your charging issue, if the alternator isn`t charging, and if it`s a Bosch, the combined regulator and brush box is replaceable in-situ as it just screws into the back. You don`t even need to remove the alternator. As the most likely faults are either worn brushes or regulator failure, it`s worth considering?
Image

Owent2005
Posts: 72
Joined: Fri Nov 29, 2019 10:14 pm
Car(s): Ford Capri 1983 Mk3 1.6LS

Re: Running battery voltage

Post by Owent2005 » Fri May 15, 2020 8:42 pm

Thanks for the pointers,
Is there a way of checking the alternator or is it the fact that the voltage isn’t high enough proves that it’s kaput?

r2vdh
Posts: 453
Joined: Tue Nov 30, 2010 3:51 am
Car(s): 2.8EFI Turbo special with LPG
Location: Sussex

Re: Running battery voltage

Post by r2vdh » Fri May 15, 2020 10:28 pm

One key thing here is you should have 12v on the small blue wire on the back of the alt when not running. What should happen is the light on the gauge bottom right will illuminate when the key is at position two sending 12v out to excite the alt when you start the car. Once started the alt will start to send its own 12v out cancelling out the initial grounding effect turning out the light.

Mc Tool
Donator
Donator
Posts: 1056
Joined: Sat May 17, 2014 8:34 pm
Car(s): 1980 mk3 capri 2l ohc T9 , Toyota Blade Master 3.5l V6, Paso , 850T,rd400, 900ss
Location: Invercargill New Zealand

Re: Running battery voltage

Post by Mc Tool » Sat May 16, 2020 3:34 am

Fuck this just spent ages typing long winded reply and the poxy #uckin web site "didnt send information" and ate my post . No time for this ,see ya
you gotta make the most :cheers: :cigar: :burnout: out of your 20's, 30's, and 40's coz when you hit 50 the "engine check" light comes on. :?

Mc Tool
Donator
Donator
Posts: 1056
Joined: Sat May 17, 2014 8:34 pm
Car(s): 1980 mk3 capri 2l ohc T9 , Toyota Blade Master 3.5l V6, Paso , 850T,rd400, 900ss
Location: Invercargill New Zealand

Re: Running battery voltage

Post by Mc Tool » Sat May 16, 2020 5:47 am

Sorry ,feel better now.
Spent a good 1/2 hour finger typing out a long explanation about voltage drop tests ,earthing issues and , of course a couple of short stories reflecting my own experiances (cant spell ascendotes ) and the poxy website thing said something about not doing something and ate my post ......and I aint doing it again :swear: :(
you gotta make the most :cheers: :cigar: :burnout: out of your 20's, 30's, and 40's coz when you hit 50 the "engine check" light comes on. :?

User avatar
Peter-S
Donator
Donator
Posts: 6887
Joined: Mon Jul 28, 2008 7:57 am
Car(s): 1985 Capri 2.0
1983 Capri 2.8i
Location: Kent
Contact:

Re: Running battery voltage

Post by Peter-S » Sat May 16, 2020 7:02 am

Mc Tool wrote:
Sat May 16, 2020 3:34 am
Fuck this just spent ages typing long winded reply and the poxy #uckin web site "didnt send information" and ate my post . No time for this ,see ya
A bit late to help now but if that happens again try clicking 'back' on your browser and you may find your typing is still there either to try again or copy and paste for a fresh go
ImageBanner by Peter Smith, on Flickr

User avatar
Andrew 2.8i
Donator
Donator
Posts: 13275
Joined: Sat Jan 25, 2014 7:38 pm
Car(s): '83 2.8 Injection (sunny days only)
'04 Toyota MR2 (owned from new)
Location: Ceredigion
Contact:

Re: Running battery voltage

Post by Andrew 2.8i » Sat May 16, 2020 7:43 am

Mc Tool wrote:
Sat May 16, 2020 5:47 am
Spent a good 1/2 hour finger typing out a long explanation about voltage drop tests ,earthing issues and , of course a couple of short stories reflecting my own experiances (cant spell ascendotes ) and the poxy website thing said something about not doing something and ate my post ......and I aint doing it again :swear: :(
I think we've all had that at one time or another. On the rare occasions I write a long reply, I simply highlight the text and copy it before pressing the submit button. That way, if I get an error message after submitting, I can simply paste the whole text into a new post. :)

Andrew.
Image

Mc Tool
Donator
Donator
Posts: 1056
Joined: Sat May 17, 2014 8:34 pm
Car(s): 1980 mk3 capri 2l ohc T9 , Toyota Blade Master 3.5l V6, Paso , 850T,rd400, 900ss
Location: Invercargill New Zealand

Re: Running battery voltage

Post by Mc Tool » Sat May 16, 2020 8:05 am

Thats what I did ......maybe . The only back key I know of is on my phone and it does take me back a step on most websites inc this one , but this time it backed me to before I started typing. Just bloody frustrating coz you go to all the trouble of explaining your diagnosis , bit of electrical theory ,all the time feeling good coz I think Im helping someone and then it takes ages to submit ,get a nonsencical message ,so I try to go back to try resubmitting ( as done before ) and its all gone, :D and Im shitty anyhow coz Im stuck at the parents doing the dutiful son thing ,came armed to the teeth but left all the ammo at home ( their place is overrun with rabbits).
In a nutshell , Owen I think you have an earth issue , possibly a broken copper track just where the membrane folds at 90deg where the harness plug goes into the dash assy. There is a long trip from the alt to the battery which could throw up some poor connections which is why you only see 12v at the battery , being as how you have 12v and the instrument reg is 5v I dont think that reg is at fault ( doesnt feed the tach by the way ). The best way to suss these faults is a volt drop test which will show up poor connections . I can tell you how to do this if your not sure . :)
you gotta make the most :cheers: :cigar: :burnout: out of your 20's, 30's, and 40's coz when you hit 50 the "engine check" light comes on. :?

Mc Tool
Donator
Donator
Posts: 1056
Joined: Sat May 17, 2014 8:34 pm
Car(s): 1980 mk3 capri 2l ohc T9 , Toyota Blade Master 3.5l V6, Paso , 850T,rd400, 900ss
Location: Invercargill New Zealand

Re: Running battery voltage

Post by Mc Tool » Sat May 16, 2020 8:09 am

Thanks Andrew , makes sense when you say it......now just gotta remember :)
you gotta make the most :cheers: :cigar: :burnout: out of your 20's, 30's, and 40's coz when you hit 50 the "engine check" light comes on. :?

User avatar
stevemarl
Donator
Donator
Posts: 4421
Joined: Wed Jul 11, 2012 6:31 pm
Car(s): Capri 1.6 laser

Re: Running battery voltage

Post by stevemarl » Sat May 16, 2020 10:58 am

r2vdh wrote:
Fri May 15, 2020 10:28 pm
One key thing here is you should have 12v on the small blue wire on the back of the alt when not running. What should happen is the light on the gauge bottom right will illuminate when the key is at position two sending 12v out to excite the alt when you start the car. Once started the alt will start to send its own 12v out cancelling out the initial grounding effect turning out the light.
Yes, that`s a very good point - esp as you have problems with the instruments! Does the ign light actually come on when you put key in pos II, and go out when you start engine? As said, the Alt. unlike a dynamo does NOT have a permanent magnet, the field magnets are electromagnetic (coils). In order to `boot up` or excite, the alternator, you do need a small current to be passing through the field coils - this comes from the Ign light. When the alt starts working it powers it`s own field and puts 12v back to this bulb so it`s 12v either side and bulb goes out. If the bulb is `out` for whatever reason, blown, broken connection, the alt will not INITIALLY charge (However, there is USUALLY enough residual magnetism in the rotor so that,once the engine is revved beyond 1.5 - 2k the alt will `self excite` and jump into life: light goes out, 14v on the batt. And it will then work absolutely normally, once it`s running it`s running (I know `cos I put an LED in place of bulb...) I`m wondering if your Ign bulb is not working, you start the car and there`s no charge cos it`s not been run fast enough to self-excite? Maybe try revving it a little, then taking batt V again.
Another thing, the electrickery gauge shows current, amps, not voltage, it shows how much charge is going in or out of the battery. With engine off, beam should cause the needle to dip (current out of batt), if you start engine the needle should, if alternator`s working, go upwards (charge going into battery). Do you ever see the needle move above the horizontal?

Owent2005
Posts: 72
Joined: Fri Nov 29, 2019 10:14 pm
Car(s): Ford Capri 1983 Mk3 1.6LS

Re: Running battery voltage

Post by Owent2005 » Sat May 16, 2020 11:40 am

Thanks for the replies,

The ignition light on the dash has never worked since owning the car, I’ll hopefully have the instrument panel off today so will be able to have a good look at it’s circuitry.

Once I’ve put it back together I’ll go over the points above and let you know how I get on.

Thanks again

Owen

Owent2005
Posts: 72
Joined: Fri Nov 29, 2019 10:14 pm
Car(s): Ford Capri 1983 Mk3 1.6LS

Re: Running battery voltage

Post by Owent2005 » Sat May 16, 2020 12:44 pm

This is the state of the PCB now that I’ve got the instrument panel out. I’m just checking which one’s are broken but I’m guessing a new one is required?
Attachments
5FB41810-9D00-4CE7-9985-6159C58BA65A.jpeg

r2vdh
Posts: 453
Joined: Tue Nov 30, 2010 3:51 am
Car(s): 2.8EFI Turbo special with LPG
Location: Sussex

Re: Running battery voltage

Post by r2vdh » Sat May 16, 2020 5:00 pm

Looks like the amp meter trace is burnt out

User avatar
stevemarl
Donator
Donator
Posts: 4421
Joined: Wed Jul 11, 2012 6:31 pm
Car(s): Capri 1.6 laser

Re: Running battery voltage

Post by stevemarl » Sat May 16, 2020 5:15 pm

Yep, as well as the burnt out ammeter track, some of the other tabs in the multiplug look a bit worse for wear. Maybe see if Martin (Caprigear) has a spare one. He possibly may have ;)
Also the instrument regulator is at an odd angle, it should sit quite square?
Don`t know if this is any help, it`s upside down compared to your pic?
Image

Owent2005
Posts: 72
Joined: Fri Nov 29, 2019 10:14 pm
Car(s): Ford Capri 1983 Mk3 1.6LS

Re: Running battery voltage

Post by Owent2005 » Sat May 16, 2020 7:46 pm

Yep the picture helps to trace where things should be. I’ll have to get in touch with Caprigear as I’m struggling to find a new PCB online.
Does it matter if the regulator isn’t square? It’s tight and not been knocked.

Owen

Post Reply