stop light and battery light

[kornnut106]

stop light and battery light has started to turn on,(it blinks on and off with a beep) i think its my alternator but can some one confirm this, the engine is running lumpy and also now the check injectors lights comes on if the car is it left to sit running for a while any ides ive been to the dealers but think i got conned thanks in advance. would abad alternator make my engine run bad due to all the eletrics etc.

[davelowe]

Unlikely, but possible. Check the battery itself first. Then check the glowplugs (if it's a diesel).

[kornnut106]

battery has been checked and OK also voltage has been checked and also OK though it has a a 1 volt drop nearly every second would the egr valve cause this maybe,.. the alternator is going into the garage that fit it ,they said their for taking the belt off to eliminate the alternator but i don't thinks its gonna last till Tues also could this do other damage to my car aslo checked the glow plugs there fine , thanks for the replies you have answered to my other posts and i appreciate it

[pw981]

Remember the red battery light on the dashboard lights up indicating a fault detected with the alternator. It usually lights up if the ECU has detected that the alternator has went above or below the set voltage range it is suppose to be working at. If it is going under (therefore undercharging) then this could mean that the alternator is not working at its full potential anymore, this could be because the alternator is failing, the belt driving it is loose, or many other factors.

When the STOP and battery light come on, are you requesting more electricity from the car? E.g, radio? wipers? headlights? rear de-mister? Just like a dud battery can cause erratic electrical symptoms in a car, so can a dud alternator.

If the garage you are going to really are taking the accessory belt off, make sure the old one is discarded and a new one fitted. Also, if it does turn out to be the alternator, if the replacement is not EXACTLY the same make/type, you may find the car will not start due to the ECU not letting it - the alternator needs programming into the ECU with... you've guessed it - Renault Diagnostic equipment.

[davelowe]

Can't argue with pw981. There shouldn't be a 1 volt drop like that. Check that all the connections to the alternator are sound - including both ends of the two wire connection to the engine multiplex module and the big fat one to the battery (both ends). Apply some WD40 but don't get any on the belt! Check the voltage when engine is running is between 13.5 - 14.8V with all equipment switched off. See if the intermittent drop still occurs. If not, switch on one thing at a time and see what causes it (lights, demister, etc). If the voltage is over 14.8V switch off immediately and do not run the engine at all.

Also check the belt tension (tight) and condition (cracks and presence of lubricants on it).

The alternator should maintain the specified range whatever standard equipment loads are applied to it. But, before you condemn the thing, phone an auto electrician for an opinion based on your symptoms and experiments. Most likely cause is the voltage regulator circuit, but worn brushes could be the problem. These can sometimes be replaced, so get a price. It may work out cheaper than a replacement - particularly if you factor in the cost of the reprogramming charge.

One other thing (especially the check injection message) - the glow plug regulator may be misbehaving - they draw a heavy current and the regulator could be turning them on and off erratically. I only mention this as it sounds as though you have already had another alternator fitted in the past, and for it to 'fail' so soon after fitting is a sign that the underlying problem may not have been addressed.

[pw981]

Thanks for your message kornnut,

I'll post my findings on here so I can share with everyone. The need to code the alternator into the ECU via Renault CLIP (the diagnostic software) is in the Renault Technical Documents in the links sections of the forum, unfortunately it is all in french.

A few quotes from the manual are:

"To refit, proceed in the reverse order of removal."

"WARNING Connect the battery; carry out the necessary programming (see Section Electrical Equipment)"

There is also a forum post here:

viewtopic.php?f=2&t=5395&hilit=alternator

[pw981]

It is the Protecting and Switching Unit which requires programming with CLIP.

The link to the thread I gave, I see no reason why no programming would blow the cars computer. I read a thread on here a while ago about someone who went to an independent to replace the alternator, and it resulted in a non-starting car. Had to be towed to Renault to be programmed. The only problem is I cannot find the thread!

I should imagine that if the alternator is replaced like for like - one shouldn't run into this 'problem'

[kornnut106]

which one is the glow plug regulator i had the upc out and checked for damage and water ingress but found non can you tell me how and where excatly this thing is i think i might be looking at the wrong bits lol thanks

[davelowe]

On mine it's behind the drivers wheel arch cover. (remove wheel and front plastic guard).

[kornnut106]

ok happened to be a faulty alternator however it has been changed and has only lasted days as its allready showing the same symptoms as before why would this do this is it because maybe the alternator dose need programming after all or did i get a bad batch off alternators from the same place iam confused

[davelowe]

Belt tension (excessive) would be my guess.

[kornnut106]

do these cars not have spring loaded tensioners on the pulleys i would have thought so but u never know lol it does sound abit noisey right enough when driving only (well i think thats waht the noise is) when i turn on the heatting the engine noise changes and it seems to help this is maddness

[davelowe]

Do you have air conditioning / climate control?

[kornnut106]

i have air con but no climate control

[davelowe]

In that case there may be a another issue. I seem to recall from the Haynes manual that there are 3 types of belt configuration. The non-air con models have a tensioner that is manually adjusted. The air con models have an automatic adjuster. This may be at fault causing premature wear in the alternator bearings. Also, to complicate matters, there are 6 grooves in the various pulleys, but only 5 are used on non-air con, but all 6 with air-con. It might be wise to check that the belt is aligned correctly ie in the same grooves in each pulley.

If you switch on the air conditioning and it helps the problem, this could be due to less load on the belt - the compressor pump may be at fault and only spin freely when switched on, that said, the tensioner would be my best guess. Puzzling though - it could be a combination of things.