Alternator / Battery Voltage and Dashlight Gremlins

[MSJW]

Hi all

I’ve had some issues with my dash where the backing light no longer works and I therefor can’t see the speedo/ fuel/ rev needles at night. The odometer is also not working. I’ve had the unit inspected and ‘repaired’ however still no joy.

I measured the battery voltage today with the vehicle off at 12.36 volts. When the car was running this climbed up to 13.8 and wouldn’t get any higher.

I understand with the alternator on voltage should be 14.2v+. There is a strange noise coming from the engine bay, sort of like a chaffing noise and I’ve had a couple of other electrics play up recently namely the passenger electric window not working and and radio cuttting on and off.

All fuses look ok and there’s no obvious wiring issue. So my question is does this sound like alternator problems given the voltage being produced?

The vehicle has a 1KZTE engine and is the 3.0l.

Cheers

 

[Steve Wright]

Hi all

I’ve had some issues with my dash where the backing light no longer works and I therefor can’t see the speedo/ fuel/ rev needles at night. The odometer is also not working. I’ve had the unit inspected and ‘repaired’ however still no joy.

I measured the battery voltage today with the vehicle off at 12.36 volts. When the car was running this climbed up to 13.8 and wouldn’t get any higher.

I understand with the alternator on voltage should be 14.2v+. There is a strange noise coming from the engine bay, sort of like a chaffing noise and I’ve had a couple of other electrics play up recently namely the passenger electric window not working and and radio cuttting on and off.

All fuses look ok and there’s no obvious wiring issue. So my question is does this sound like alternator problems given the voltage being produced?

The vehicle has a 1KZTE engine and is the 3.0l.

Cheers

I measured the battery voltage today with the vehicle off at 12.36 volts. When the car was running this climbed up to 13.8 and wouldn’t get any higher.

I cannot explain about the problems but I would not worry about those voltages they seem fine, there is only a couple of volts difference, but have you checked the connections on the Alternator as it could cause cause problems,also have you checked the lamps behind the clocks ?

 

[Trevor]

If you are able to take a video of the noise and post it up that would be great. If you have the 1KZTE engine, I'm guessing you have a 90 (SWB) or 95 (LWB) series Colorado and not the 100 series.

 

[MSJW]

Thanks guys. It’s actually a Granvia (sort of like a crossover between the Surf and a Hiace). I do have a 2.4 Surf of the same generation, just wasn’t sure where to post this.

Yes I’ve checked the bulbs and they’re all ok. I sent the dash cluster itself off for ‘repair’ but nothing has changed. The ECU was also repaired over Christmas.

It’s sort of like a whirling sound. It might just be the viscous fan? What’s strange is some of the other electrical components are acting up. For a couple of months the driver chair wouldn’t adjust (motor driven) yet today it worked fine after having the engine running on / off throughout the morning.

I’m going to hook up another battery and see if it changes anything...

 

[MSJW]

Tried another battery and am getting the same sort of readings with the multimeter. 12.5v or so with engine off. Climbs to 13.4 or so with engine idling and then caps at 13.9 if you rev it a little. Seems that the alternator is working as expected.

There is an aftermarket immobiliser fitted which I believe has had the fuses removed to prevent it from working. I wonder if this could be causing these miscellaneous electrical faults...

 

[StarCruiser]

The voltages you have posted show that the alternator is not sending out the required 14.4v. It will give an amount of charge to the battery but will under charge it, killing it over time.

It sounds very much like you could have some loose connections somewhere, possibly some corrosion to connections. Check your earth strap(s) are connected between Body/battery-and engine. Check your battery connections, clean and smear with petroleum jelly before refitting and tightening them enough for them not to move.

 

[uHu]

Either what SC says, or one shorted diode in the alternator. If one out of the 6 diodes is shorted, it gives symptoms like that, a too low charge voltage, and also a lot of AC (alternating Current) which disturbs the electronics.
And, arresting a comment above here: A couple of volts makes a huge difference in a 12 volt (nominal) system. It is the difference between no charge and 100 % charge.

 

[StarCruiser]

And, arresting a comment above here: A couple of volts makes a huge difference in a 12 volt (nominal) system. It is the difference between no charge and 100 % charge.

Exactly what I was going to say, if my Chinese hadn’t arrived .

Hadn’t thought of the diode, simply an alternator fault if the loose connections didn’t materialise. I’ve not tried it but if that’s the case you may be able to detect a voltage with a multimeter set to AC Volts but you’ll almost certainly be draining the battery over a short time and have a significant current flow through the alternator wire with the engine off.

Good call Uhu.