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freak charging system fault

trolleyjack

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Location
Kent
Car
Accord D 2.2 Exec
Had permanent battery charge light on, and read code P2004 IMRC solenoid last week,

Alt test :-

Battery voltage at rest 12.6

Meter tested alternator, output only 11.7 on tick over, 9.8 when given electrical load ,lights, air con, heated rear window etc.

Conclusion :- goosed alternator.

Replaced alternator with new aftermarket unit.

Replaced solenoid valve with used one, cleaned IMRC swirl valve and sensor, not really that carboned up, but quite oily as to be expected.

Now battery charge light goes out after starting, but will temporarily go on and off at certain rev range, or when electrical loads switched on or off, will extinguish permanently if air con is left on.

Read online about Hondas with ELD faults, ELD module not changeable on a diesel Accord ( new fusebox only cure, yeah right )

No codes for ELD fault recorded, but erratic electrical surge drop faults similar to those on petrol variants.

Fitted used fusebox, symptoms remain the same.

Battery charges no probs, voltage across battery steady 12.6 at rest, all electrical devices on at tickover 14.1V, 14 .3V at 2000 rpm. so charging OK.

No resistance between ALT to battery, both positive and negative terminals, all connections tight, alt , starter solenoid, battery terminals cleaned and greased, neg Battery earth strap cleaned, wing clamp sandpapered to bare metal and greased, drivers side earth strap wire bushed and greased the same.

Given the light stays out only when air con engaged, I suspect it may be something to do with load on the Alternator clutch pulley, the belt is tight the spring on the tensioner is still strong.

Does anyone know if the charging system is sensitive to non Honda alternators ie slighly different load rf frequencies ETC , or have any suggestions as to what to try next ?

Cheers
T.J.
 
Does sound like a faulty clutch on the alternator to be honest, you’ve checked everything I would have suggested.

P2004 indicates your imrc was stuck open. If it happens again after the valve replacement then I would advise egr off.
 
I must be out of the trade too long , I didn't know the alternator had a clutch , where does the battery feed to alternator come from , is it the starter or battery ? is the earth lead alright from body to engine , the alternator light should not come on at all , is there a fault present , which could have caused your original alternator to become defective , I would check battery voltage at battery then check it to alternator to see if you have a voltage drop , I have just done my friends Nissan Xtrail a few months ago , he had a similar problem , I told him to replace engine to body earth strap , I was told I didn't know what I was on about by another sparkie , even though I was min the trade thirty years before I was medically retired , sometimes its best to go to basics .
 
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