Celica -76, 18RC poor voltage regulation.

**Paxman** · 03-07-2014, 06:13 AM

I spoke too soon...

The charging is still unstable. Today I shoot a lousy cellphone video showing the voltage and the ammeter. Note that the voltage at first is over 15 volts...
When the ammeter goes crazy I can see all the lights dim in sync with the ammeter needle so something is really wrong. I can also hear the engine sound change when the ammeter goes ballistic...

One a positive note I haven't seen the low voltages that I saw when I started this troubleshooting so the original problem seems to be sorted...now I only have to find the reason that the voltage freaks out...

**ctrain** · 03-07-2014, 10:26 PM

try and replace the regualtor with the old one just to see if it makes any difference, all regulators have a specific value set to them by the manufacture, it may look that same but will regulate a different voltage. And if it is the wrong one you electrical system wont like it at all.

**Paxman** · 04-07-2014, 07:20 PM

Yeah, I did try with the old regulator and that is much more stable so you might be correct there...the new regulator may look the same but maybe it's totally wrong for the car. As before the voltage was low with the old one but I found an instruction how to adjust the voltage which I did. Now the voltage is mostly pretty good at normal operation situations but still too low at idle, too high with no loads and and sometimes it gets too low an normal operating.

Getting really tired of this so I decided to order an electronic regulator to see if that is better. I'm going back to the shop where I bought the regulator to try to return it and ask if they have a alternator that I can test in the car to see if the charging is stronger at idle.

Basically I'm back to square one, charging is not enough at idle so when the cooling fan starts it drains the battery with the headlights on. If the electronic regulator and/or a new alternator doesn't resolve this I'll just have to live with it. Now the ammeter works so I can monitor the charging which means that the car will never die due to depleted battery, I now have a charge warning light and all new wires in the charging circuit. Also I have a main fuse, the main circuit breaker situated inside the car where I can reach it and a fusible link so I feel much more secure.

I'll keep this thread updated.

**Paxman** · 05-07-2014, 07:18 PM

Would it be possible for some of you guys that have a stock 18R ( C ) to check what voltage you have at idle revs, headlights on and foot on the brake? People are saying that I should not expect any charging at idle...to me that seems a bit strange...

**allencr** · 06-07-2014, 06:00 PM

Stalling shouldn't be a symptom of low voltage until it's down around 9V or so.

Cars with generators, before the switch in the 60's to alternators with their wonderful output & simple parts & long life, rarely if ever put out 12V at idle.
Unless it's a cop car or something that sits idling for a long time, what difference does it make if there's no output? Any decent battery should be able to run the fuel pump, ignition, lights, AC & fans for 30 minutes without need ing the alt to keep it charged up. Adding a big sound system & amp might cut that down to 10-15.
> 14.5V is NFG for the battery!!!!!!

**ctrain** · 06-07-2014, 07:59 PM

One of the reason's why alternators replaced generators is because the CAN charge at idle, does the alternator have the right size pulley on it?

**Paxman** · 06-07-2014, 08:49 PM

Originally Posted by allencr

Stalling shouldn't be a symptom of low voltage until it's down around 9V or so.

Cars with generators, before the switch in the 60's to alternators with their wonderful output & simple parts & long life, rarely if ever put out 12V at idle.
Unless it's a cop car or something that sits idling for a long time, what difference does it make if there's no output? Any decent battery should be able to run the fuel pump, ignition, lights, AC & fans for 30 minutes without need ing the alt to keep it charged up. Adding a big sound system & amp might cut that down to 10-15.
> 14.5V is NFG for the battery!!!!!!

The car is all stock now except for the electric cooling fan, no sound system at all, no ac, no central locking or alarm system...nothing. And the alternator still can't keep the charging on the positiv side at idle and the brake lights on even if the cooling fan is not running. I don't know what NFG means...sorry...

**Paxman** · 06-07-2014, 08:56 PM

Originally Posted by ctrain

...does the alternator have the right size pulley on it?

It's stock but I've been considering if it need a different size pulley. My best hope is that the electronic regulator will sort this...I still see voltage over 15 volts now and then so the alternator obviously have power to charge.

**Paxman** · 12-07-2014, 04:58 AM

Just got in after testing the electronic voltage regulator that came in the mail today...WOW!!!! Talk about difference!! The ammeter is really steady and the voltage was never over 14,7 V! It's still a little low on idle with normal users on so that issue is still there but since the ammeter shows what's going on it's not much of a biggie. I can live with that for now and maybe look into if I need to get a new alternator or perhaps changing the pulley. It should be a smaller one right?

**ctrain** · 12-07-2014, 11:43 PM

good news mate, if you do want it to charge more on idle then yes a smaller pulley is needed

**Paxman** · 16-07-2014, 08:27 AM

The shop where I bought the mechanic regulator is closed for summer so I'll have to wait a couple weeks to go and try to return the regulator and see what he thinks about the low charging at idle.

Is there any risk involved in changing the pulley to a smaller one? I'm thinking too high rpm at WOT...4000 rpm's is what my 18RC manage. Where can I even get a smaller pulley that fits my alternator...? Does generator guys generally have a box of misc pulleys?

**RAAAH23** · 16-07-2014, 05:22 PM

Hey mate you could always go for the EA Falcon 85amp conversion. It also internally regulated haha but it would fix your charging and idle woes.

http:////www.toymods.org.au/forums/t...s-engines.html

Edit: Just realized you're in Sweden you could try and find one on eBay and hope they ship to you.

**Paxman** · 16-07-2014, 07:20 PM

Hey Alex!

Yeah, I did find that option and read the thread but as you state, I live in Sweden and I don't think there has ever been a EA Falcon here!

eBay would be an option but most times the shipping kills the deal.

My charging is not too bad now so I'm not really motivated to shell out a lot of bucks just to get it a little better. The car is not my daily driver so I can live with the small inconvenience of turning off the headlights when the cooling fan runs.