Alternator issue

Hi all i have a 1993 1uzfe in a surf. I Put a new battery on it and went for a drive. after 1 hr of driving i stopped and when i went to start it, it only just cranked. I did have lights and heater on for the full time.

Did a test and on battery it is 13.9v unload and 13.3v lights on and heater on. Have looked on net and could be belt slipping so can order on of them. The belt is old. Did rev it to 2000rpm and it did give 13.9v unloaded. Not sure if there is a regulator on it or built into the alternator?


Super Moderator
Staff member
The Alternator is internally regulated.

If you have 13.9v when running it sounds like it's not the alternator.

The voltages you provide sound like they with the engine running.

What it the battery's resting (engine off) voltage?

A simple check would be to swap the battery for a known good one and see how it goes.
Thanks for the reply.
I think the voltage was 13v on the battery with engine switched off. I will swap the batteries.
I got a vvti I am taking the engine out of and the car came without a battery. I got a new one and put that in the surf and old battery in the donar car while I was striping it out to check it still cranked over etc.
I will put the old battery back in the surf and the new on in the donar car and see if that sorts the problem out.
Just something else to add to the mix. Swapped the battery over and the battery finds it a lot harder to crank the 1st gen uzfe in the surf than the vvti. It just about cranked over the surf uzfe but the vvti engine it had no problem like the battery was new. Both batteries on the surf uzfe is about 13.9v when engine on and 12.6v when engine off.