Had the battery light on so garage tested then fitted new alternator. That was 3 weeks ago. Today the battery light came on and charging at 11.4 V. Went off and charging at 15.1 V. This happened about every 10 seconds for about 5 times. Light gone out now and has been out all day. If not the alternator what else can it be.
Intermittent Battery light on
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Could be an intermittent connection or even a faulty alternator. Was the battery tested? Was the alternator brand new or re-con? I would take it back to the garage.
It was a new alternator and my battery is less than a year old. If it persists I will contact the garage. It happened again this morning, regular battery light on and off. Now driven a while the battery light stays off and charging at 15V. Could it be the ECU as I know this regulates the supply to the battery??
15V seems a bit high; usually about 14.4V. Although the ECU provides fine control, I suspect the problem lies elsewhere. It could be that the field connection from the ECU to the alternator is intermittent. This connection has sometimes been found to be completely missing following alternator replacement.
Have you checked your battery volts without the engine running? Fully charged battery on light load should have 12.6V.
Have you checked your battery connections, particularly the ground connection to chassis?
Have you checked your battery volts without the engine running? Fully charged battery on light load should have 12.6V.
Have you checked your battery connections, particularly the ground connection to chassis?
The alternator should have an internal regulator. I would lean towards a faulty alternator and/or a loose or dirty connection.
Yes, it does, but the ECU also provides control via the field connection.
I would be checking connector first.
I have had many people come to me with starter and alt faults.
Most people "get" voltage. That is fine, with electronics, most circuits are voltage level driven, very little (if any, and if then is only "signal) current) Most don't get current, especially high current. The alt leads handle highest current on the car, except for the starter motor.
I have NEVER seen a car come back from a shop with a cleaned alt/starter lead. With starter leads, they just replace. I have seen so many cars where people were told they needed new starter/alt = was connections.
People understand "connected/disconnected"; but most don't understand resistance across a low resistance connection. A few ohms can create heat that then causes expansion/intermittent faults. Those sorts of low resistances are impossible to check with multimeters, and need meggers. Even elec shops don't have them these days, if in doubt, they replace. And unless you understand cct voltage drop under high current load implicitly; a multimeter won't tell you much in a "few ohms" situation.
Auto elecs don't change bearings/brushes/coils anymore. Here they don't even stock ANY brushes or bearings. They just exchange entire assy. I don't, I fix it. I will NEVER get a new alt for hundreds when $10 worth of brushes will fix............. but most don't have the means, so fair enough.
My sons car burnt out the alt connection, as was dirty and they fitted a new, higher o/p alt = didn't clean it. When I went straight to the alt, "It can't be that/just replaced....." = it was the lead. A snooty woman in a BMW that wouldn't start (when I asked to get to battery) "It CAN'T be the battery, they just replaced......."; leads corroded/not cleaned/not done up properly.
Point is - when something goes wrong on a car and the last thing was "somebody changed"; it is often there..........but many just "keep changing/replace." Can do that all day (and at great expense), but no point if connection not good.
I would be removing alt lead (DISCONNECT BATTERY/LEAD ALWAYS LIVE). If it isn't bright metal clean, wire brush it until it is. They won't do that. Even if you ask them to. Well, my experience anyway.
Then you can move on.
It COULD be the new alt. It is far more likely they have disturbed a dirty/hard working alt connection/dirty faces not connecting properly; and easy to check. Problem with cars now is that these terminals are crimped; and crimped terminals can have corrosion inside = same problem.The "industry" loves crimped connections, I hate them for high current, but everyone uses them, so you won't win. We had them fail on a 10 million dollar missile guidance radar, and they would NOT admit the crimps were the problem, when we could see they were. So the car industry is not alone...............
It only takes a couple of ohms. Those connections (and the connections between case and engine block )MUST be spotlessly clean, otherwise you can chase other problems all day. Engine block connection very large surface area, so rarely a problem, but if lots of corrosion, it is possible.
If anyone has elec training, and the above is "suck eggs" I apologize. I hesitate to mention elec theory, as people are funny. Here (in Australia), people get their science and medical info from scientists and Dr's. But they get their elec advice "from a guy down the pub" and abuse any elec tradie who "dares to defy the pub guru". Hence why you never discuss it with the average Joe here.
This forum is "more forgiving"............... Thankfully.
I have had many people come to me with starter and alt faults.
Most people "get" voltage. That is fine, with electronics, most circuits are voltage level driven, very little (if any, and if then is only "signal) current) Most don't get current, especially high current. The alt leads handle highest current on the car, except for the starter motor.
I have NEVER seen a car come back from a shop with a cleaned alt/starter lead. With starter leads, they just replace. I have seen so many cars where people were told they needed new starter/alt = was connections.
People understand "connected/disconnected"; but most don't understand resistance across a low resistance connection. A few ohms can create heat that then causes expansion/intermittent faults. Those sorts of low resistances are impossible to check with multimeters, and need meggers. Even elec shops don't have them these days, if in doubt, they replace. And unless you understand cct voltage drop under high current load implicitly; a multimeter won't tell you much in a "few ohms" situation.
Auto elecs don't change bearings/brushes/coils anymore. Here they don't even stock ANY brushes or bearings. They just exchange entire assy. I don't, I fix it. I will NEVER get a new alt for hundreds when $10 worth of brushes will fix............. but most don't have the means, so fair enough.
My sons car burnt out the alt connection, as was dirty and they fitted a new, higher o/p alt = didn't clean it. When I went straight to the alt, "It can't be that/just replaced....." = it was the lead. A snooty woman in a BMW that wouldn't start (when I asked to get to battery) "It CAN'T be the battery, they just replaced......."; leads corroded/not cleaned/not done up properly.
Point is - when something goes wrong on a car and the last thing was "somebody changed"; it is often there..........but many just "keep changing/replace." Can do that all day (and at great expense), but no point if connection not good.
I would be removing alt lead (DISCONNECT BATTERY/LEAD ALWAYS LIVE). If it isn't bright metal clean, wire brush it until it is. They won't do that. Even if you ask them to. Well, my experience anyway.
Then you can move on.
It COULD be the new alt. It is far more likely they have disturbed a dirty/hard working alt connection/dirty faces not connecting properly; and easy to check. Problem with cars now is that these terminals are crimped; and crimped terminals can have corrosion inside = same problem.The "industry" loves crimped connections, I hate them for high current, but everyone uses them, so you won't win. We had them fail on a 10 million dollar missile guidance radar, and they would NOT admit the crimps were the problem, when we could see they were. So the car industry is not alone...............
It only takes a couple of ohms. Those connections (and the connections between case and engine block )MUST be spotlessly clean, otherwise you can chase other problems all day. Engine block connection very large surface area, so rarely a problem, but if lots of corrosion, it is possible.
If anyone has elec training, and the above is "suck eggs" I apologize. I hesitate to mention elec theory, as people are funny. Here (in Australia), people get their science and medical info from scientists and Dr's. But they get their elec advice "from a guy down the pub" and abuse any elec tradie who "dares to defy the pub guru". Hence why you never discuss it with the average Joe here.
This forum is "more forgiving"............... Thankfully.
Spot on as usual; and saved me duplicating that (field etc) in my response.
15 volts seems high to me, should be approx 13.5 to 14.5.
Intermittent/dodgy connections can cause this, as reg assumes perfect connections.
While some see voltage level as a "pissing contest" (Brit bike site I left, blokes running "9 volts on a 6 volt system, as it runs better!!!" (which is like our 12 volt system running 18 volts!!!!!!!!!! , obviously into boiling batteries) ); 13.5 to 14.5 is the generally accepted level.
If there is a dodgy connection, the alt will crank it up a bit to compensate, hence the 15. Was the 15 measured with the EVIC (quite accurate) or a multimeter??? I have meters I trust; but I have multiple meters to cross check. So just check if ACTUALLY 15 volts with more than one meter, before any panic.
But 15 "cranking up to compensate for a drop across a connection" brings us back to connectors.
My alternator was changed several years ago by a Chrysler dealer. I kept the old one for a post mortem and discovered that one brush and slipring was worn to a frazzle, but the other pair were pristine. Changing brushes would have been easy, but sliprings less so.
Concur.
I have never had to change a slipring/wouldn't bother; but has always been bearings or brushes. Given that costs about $20 and $10 respectively ........... why not? Have had to change a diode or two in one out of 20 or 30 alt overhauls.
All those were other cars/more common alts, so had parts laying around, haven't had to do the Chrys one yet. If/when it does need it, I'll dismantle and check first before I buy another. If can "re bearing/re brush" will do same.
Here they keep almost no parts at auto elec. I had to overhaul a common Bosch alt (very common here) and asked auto elec for brushes. He said "mate, we don't carry/change brushes, we haven't even got a soldering iron..." EVERYTHING is "order in/exchange".
Around the corner - brushes - $6. $330 exchange for alternator they told me I needed.
The way of the world.
CRD alternators have a poor reliability record. This was usually blamed on its location right under the oil filler cap and which could lead to oil contamination. The solution was to fit a protective shroud, which I had already done, so I was surprised when failure occurred at about 30K miles. There was no sign of any oil contamination, the car was out of warranty and there was no "goodwill" from Chrysler. I did, however, manage to find a re-con specialist who was offering a reasonable fixed price to repair any alternator. I decided not to proceed at the time, but kept it in the garage "just in case".
A different story: I recently sold my 25 yr old Audi A4 1.9TDi, with 150K miles on the clock. Original Lucas (made in England) alternator still working perfectly.
A different story: I recently sold my 25 yr old Audi A4 1.9TDi, with 150K miles on the clock. Original Lucas (made in England) alternator still working perfectly.
I have heard that re the oil getting to the CRD alts. Obviously car alts have to be completely open/have huge airflow, and with that comes dust/dirt any contamination in that airflow, which they normally handle except for the brushes.
I have worked on many boat alts, and they completely seal the brushes; they do it for "no sparks in boat bilge/fumes" reason, but that would have worked on the CRD maybe if they had foreseen that.
I have had mixed results with Lucas alts. The older ones use large main diodes in huge heat sinks - one on my Jag (69) never a problem, and been there /I have had it 22 years. The "newer" ones (on my 76 Triumphs) multiple failures with diode packs. They just aren't up to the job, the diode pack has three tiny square heat sinks, and diodes smaller than a pea barely touching heat sink - just a bad idea. I replaced the one on the Stag with a Bosch - no problems. NEVER had a Bosch main diode failure (again, huge heat sinks/pressed in diodes with huge contact), and only recently had a field diode fail (easily replaced) out of the dozens I have done.
The newer generation alternators have vented sides as well as ends, which helps airflow, but also exposes internals to more contaminants with that cooling air. A compromise they have to have.
Mine is a V6 and 2007 model. Done 270,000 k's, so will have to do the alt one day if the car keeps going. I will address it then; either get a another one when the time comes, as here they are about $400 I think. But then I will check old/overhaul/have as a spare if it can be saved. Unless it comes off and just brushes.................. then can overhaul - replace.
My alternator's brushes and sliprings had internal shrouds, so it would have had decent protection, in addition to the external shroud. There was no sign of any oil contamination.
The new MOPAR replacement cost £481 plus £378 labour plus 20% VAT on the total. The official replacement procedure requires the engine to be lifted off its mounts and hence is labour intensive. Some owners have managed to replace from the top. At least the replacement came with 2 yrs Chrysler warranty.
The new MOPAR replacement cost £481 plus £378 labour plus 20% VAT on the total. The official replacement procedure requires the engine to be lifted off its mounts and hence is labour intensive. Some owners have managed to replace from the top. At least the replacement came with 2 yrs Chrysler warranty.
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