Temperature compensating alternators (1 Viewer)

[fullthrottle]

Hi All

I have a 2002 LX470 and needing to wire up a couple of VSR's to supply two power feeds to the caravan fridge and ESC (Electronic Stability Control).

However I have been reading (possibly too much) that Toyota does distribute temperature compensating alternators in some of their makes. Which basically means when the engine gets up to temperature, the ECU changes the alternator output in some way.

Some say that the voltage output drops, which is bad for a VSR as that can cause the VSR to shutoff if the alternator does drop the output, under normal circumstances. Thus a programmable VSR might be better.

Anyway, my query..... Does anyone know if a 2002 LX470 has a temperature compensating alternator?

Cheers

 

[Tapage]

I know by experience that my alt ( Tundra 150 amps ) as well as the factory 60 and 80 series alternators drop their V as a normal process when your batteries get charged ..

With top 14.4 and as low as 13.8 I know those as normal Toyota alternator V values while the alternator it's in good shape and between their normal temp operating values ..

I also recall when my alternators are about to die or they are getting way to hot the drop the V output, possible due to a opening diode or a faulty V regulator.

There are many variables in there, connections, cables, batteries to take in mind too

 

[BillZ260]

I thought it was more engine speed related, idle = low output, on road speeds would be normal 14.xx output.

So if your truck is cold the output maybe high because the 'choke' is on.

 

[dogdaysindurham]

If you have the FSM manual for your year LX it should say if it were. I looked at my FSM and it looks like for the 05 100 series with the 130 amp, it isn't temperature compensating.

But it were it would show two temperature ranges and the corresponding voltages like this:

But from what I could find from 03 ish 100 series:

 

[fullthrottle]

Thanks all for the input.

OK, I've come to the conclusion that I should go with a programmable VSR so that should the regulated output voltage drop due to temp or ECU control I can set the voltage for when the VSR disconnects the secondary feeds.

Here is more of a read on the subject: New Vehicles Technology Can Affect Dual Battery System'S Charging Performance | REDARC Electronics

In my cases, I'm not using the VSR for charging a second battery, so I don't need to worry about achieving full charge.

Here is a rough plan of the install for those interested.

Cheers