Clementine's Garage
Clementine the Cat
 
Image of flower
Yellow R4
 
Réparateur d'automobiles

R4 F6 battery light not illuminating

Pete Isom

Enthusiast
Messages
179
Location
Raunds, Northamptonshire
#1
hello. Proud and sad owner of an f6 van. Love the truck. Had a few bulbs out. Have fixed all I think apart from the battery warning light. I get nothing even with known good bulbs. I've tested the circuit to the door pillar and get good live signal but I assume the earth is the other side of the clocks and this gives me nothing. Any one have ideas or what I can check. Or a good set of clocks near me to test with? Thanks. Pete. Bedfordshire
 
Messages
242
Location
Poole
#2
hello. Proud and sad owner of an f6 van. Love the truck. Had a few bulbs out. Have fixed all I think apart from the battery warning light. I get nothing even with known good bulbs. I've tested the circuit to the door pillar and get good live signal but I assume the earth is the other side of the clocks and this gives me nothing. Any one have ideas or what I can check. Or a good set of clocks near me to test with? Thanks. Pete. Bedfordshire
The battery warning light uses a different system to most lights - wires go to the alternator and +12 volts but none go directly to the chassis/earth. Best to check wires from the alternator - when the alternator is working, the warning bulb sees +12 volts on both sides of it (therefore it doesn't light up) - one is from the alternator +12v output, one from battery +12v via ignition switch etc. When the alternator isn't working, the bulb still sees +12 volts on the ignition switch side, and sees a chassis/earth (well, almost) via the now-dead alternator wire windings on the other side (now effectively a long bit of wire), so the bulb lights up.
If the wire to the bulb from the alternator is broken/dirty/missing then the bulb will never see earth, and never light up. Probably wise to check the alternator also works (over 14 volts when engine is running at or above tick-over).

Alternators etc always confuse me - sorry if I 've got it wrong !
 
Last edited:

mr-reno-139

AKA Paul Cunningham
Messages
2,005
Location
lancing west sussex england
#4
Conventional Renault wiring for ignition switched 12v feed is yellow
The alternator may have a tiny + and lamp wire is designated L
Check Mr Haynes publication for diagrams
How old is car as maybe got separate regulator box if pre 1980
Pre 76 had dynamo
 
Messages
242
Location
Poole
#5
Thanks will look in morning. Any ideas on which colour wires go where?
I knew there would be a hard question coming !
I think the alternator/charging bulb should be connected to a yellow or a red wire coming from the regulator box which is part of (screwed into) the alternator. I've looked at Haynes manual (p319 for 1983-onwards cars like your C-reg) which is a bit baffling, and I can't make out more than that. If it helps, there will be 12 volts between those two wires with the ignition on and the engine NOT running. I used this fact to power a fuel-pump that only worked when the engine was not running (it's a long story)....
 

Pete Isom

Enthusiast
Messages
179
Location
Raunds, Northamptonshire
#6
Roger that. Appreciate help. I've noticed my Haynes book is for up to 1976 cars. No wonder it made no sense. I'll report back tomorrow. Thanks
 

Pete Isom

Enthusiast
Messages
179
Location
Raunds, Northamptonshire
#7
Ok pic attached of my alternator. I have 12v on the red cable with ign on. And nothing on the yellow cable marked l for lamp not tested if charging when running yet but recall the lights dimming at idle and brightening when revved.
 

Attachments

Pete Isom

Enthusiast
Messages
179
Location
Raunds, Northamptonshire
#8
Just a though. Engine running I have a high pitch squeel as well. Not a fan belt noise. Only owned for three days so unsure if it's related
 
Messages
321
#9
Try this method to confirm if the wiring and the warning lamp are O.K.: switch on the ignition but DON'T start the car engine and then earth the lead running from the warning lamp to the alternator. If you are't sure which lead it is get an assistant to sit in the driver's seat and then BRIEFLY touch the wires to the car's frame, which is earth. Earthing one of these wires should make the warning light illuminate, thus confirming the bulb and the wiring is in good order. Be careful you only touch the wiring to the earth BRIEFLY, as if you're unsure which lead is connected to the warning light you MIGHT have a dead short; don't panic, a BRIEF tap the the car frame won't do any real damage.
 
Messages
242
Location
Poole
#10
The wires are the right way around at the alternator, though the crimp-ends are not the Renault originals, so bad or corroded DIY crimped connections are another place to look.
 

Pete Isom

Enthusiast
Messages
179
Location
Raunds, Northamptonshire
#11
Just before I do this. The alternator connection where the yellow cable is gives me nothing ign on or off. The other gives me 12v live. So before I look to test the cars loom. Should the yellow cable at the alternator give me anything on the multi meter.
 

mr-reno-139

AKA Paul Cunningham
Messages
2,005
Location
lancing west sussex england
#12
Oops I was wrong on colors sorry noise likely to be tensioner bearing
Available separately about £4 on ebay I've forgot size too now must be all these modern Renault I have to work on giving me headaches
 
Messages
242
Location
Poole
#13
Just before I do this. The alternator connection where the yellow cable is gives me nothing ign on or off. The other gives me 12v live. So before I look to test the cars loom. Should the yellow cable at the alternator give me anything on the multi meter.
The yellow must be the feed to the bulb; on my car it is about +2.6 volts when the ignition is on but the engine not running (bulb lights up, as it has about 10 volts across it); when the engine is running, it's at +battery voltage (14v or so) - the same as the red wire (bulb goes out - there's no voltage across it).
If there's no sign of life on the yellow wire at any time it's possible that the alternator regulator has failed. This isn't a certainty, as I've not checked yellow-wire-voltages without a bulb in - it's possible your troubles are simply the wire isn't getting to the bulb (try another length of wire temporarily to duplicate the yellow wire going to the bulb).
The alternator regulators are available separately to screw into the alternator, but may be hard to find (check which alternator you have, and compare cost with new/refurb whole alternator - millions of the same alternators would have been made, not just for the R4.)

By the way, I am not sure if this is always the case, but at least sometimes if the bulb never lights the battery never charges! The bulb is an essential starting device for the alternator. I had this with an old Volvo - bad connection at the instruments left me wondering why the windscreen wipers were getting slower and slower as I drove along - the bulb had a bad connection, and it had not lit or connected up since I put the key in, so the alternator never switched on and the battery was getting flatter the more I drove on. One hard slap on the top of the dashboard and the bad contact was remade, the alternator started charging and wipers immediately speeded back up (though whacking was only a temporary solution)!
 

mr-reno-139

AKA Paul Cunningham
Messages
2,005
Location
lancing west sussex england
#14
Interesting
I thought maybe incorrectly it seems that the terminal marked L provided an earth return point for the dash bulb when engine not charging battery and disconnected the earth if it's actually reaching correct voltage
I have quite a few R4 charge at correct voltage even with light coming on at random times
Changing regulator pack fixed it
Apologies if I am confusin matters
 

Pete Isom

Enthusiast
Messages
179
Location
Raunds, Northamptonshire
#15
All bulbs are now in the dash. I'm not a great user of the multi meter. But touching the alternator terminal marked L gives me no reading ign on. I will test the dash bulb. Are we saying I need to earth the yellow wire to check the lamp comes on?
 
Messages
242
Location
Poole
#16
No Pete - the yellow wire should never be earthed (would probably blow the regulator if it's not blown already). It should be connected only to the warning bulb. The other side of the bulb should be +12v when the ignition is on, and when engine is running. You could lash up a good small bulb with wire in the engine bay to check the regulator/alternator perhaps? (bulb between yellow and red wires from the regulator)
 
Messages
242
Location
Poole
#17
Interesting
I thought maybe incorrectly it seems that the terminal marked L provided an earth return point for the dash bulb when engine not charging battery and disconnected the earth if it's actually reaching correct voltage
I have quite a few R4 charge at correct voltage even with light coming on at random times
Changing regulator pack fixed it
Apologies if I am confusin matters
Paul - I guess that's about right! The yellow is effectively the earth to the bulb when the engine is off - but the earth is via some alternator wires first. The yellow then becomes +ve when the alternator is working.
 
Messages
242
Location
Poole
#19
Don't worry Pete - if you can get to the side of the warning bulb holder that is not +12v (when the ignition is on - take the bulb out to make sure when you check this), then connect that side of the bulb-holder to where the yellow wire ends at the alternator with a long wire (speaker cable would do the job just for testing purposes). Put the bulb back in.

If the bulb then lights up as expected when the ignition is on, and goes off when the engine is running then the problem is just the connection between yellow wire and the bulb-holder. Otherwise alternator/regulator is toast.

(Make sure the yellow wire has a good connection to the regulator - that push-on crimp connector on the end of the yellow wire is not factory-standard.)
 
Top