electrical fault.

[micra99]

Hi, i have a 2001 Micra1.4 k11 which has just developed a very odd electrical fault.
when i start the car everything seems normal for a few seconds.
ie, all warning lights go out but then when i increase engine revs to move off the Air Bag warning light starts flashing
and the radio turns off and the all the instruments stop working.
By this i mean the rev counter freezes at about 800 rpm, the speedo stops working and the other two gauges stop working.
I have taken the instrument binacle out but the wiring at the back seems fine.
i have also pulled out the radio to see if any wires are chafing but everything appears to be normal.
Does anyone have any suggestions as to what this might be.

 

[richardwbb]

the Air Bag warning light starts flashing
and the radio turns off and the all the instruments stop working.

Am no coilpack expert so i've learned but that there i would look for mass and be confident it is not abs. you actually can have a dead (no lights) running car or the other way around, i think it might be hard to fault search but solution itself not hard

 

[micra99]

i have managed to find the source of the problem, but what the problem is i dont know. If i pull off the grey plug from the back of the alternator the dashboard starts working normally again. If i then plug the alternator back in the alternator starts making a stange noise and the dsah stops working. Does anyone know what the grey plug does. Is it a voltage regulator and how does that effect the dash?

 

[fuzzy-hair-man]

Most gauges and thier sensors want a constant voltage, if the alternator isn't supplying this they could act up, there's replaceable brushes and voltage regulator on most alternators or you might be able to swap with a known working alternator or brushes / voltage regulator.

 

[frank]

that plug feeds the field coils inside the alternator (to regulate the current)
you need to test the voltage from the alternator with a meter first

 

[richardwbb]

I had a starter-makes-die-dash problem. I replaced starter for new, same problem :s Then replaced igintion switch and car started. Then put back the original starter (really the one came with the car and i had it been reworked long before this) and started like 5 times. Same weird noise from relay. Now I use the new starter and can't tell you what had being going on.

You might want to start from battery plus to starter tiny cable but if you fry something you will fry it good. This only works if ecu has became online which is if dash goes christmas it probably is. But this is kind of the not recommended way

 

[micra99]

Problem solved. I fitted a new alternator and everything is fine now. I did however have to replace both head lamp bulbs and a few dashboard bulbs as the alternator was seriously over charging.