Remove Alternator

[new yaris owner]

Need to replace alternator on 1999 Yaris GS.

I've looked in the Haynes Manual and looks nasty.

Anyone done this, with any tips please. ?

i.e. is it best moved from the bottom or top of the car ?

[Woody27]

Easy as. Got a guide i can post up later. It is easier from the top. First you disconnect Battery, unplug a plug from alternator and remove a cover and then a larger cable to alternator. Then it the adjustor bolt on top and the mounting for the adjustor arm and then one more bolt at bottom. That is the rough jist of it.

[new yaris owner]

Easy as. Got a guide i can post up later. It is easier from the top. First you disconnect battery, unplug a plug from alternator and remove a cover and then a larger cable to alternator. Then it the adjustor bolt on top and the mounting for the adjustor arm and then one more bolt at bottom. That is the rough jist of it.

Sorry , I forgot to mention it's a 1.0 litre 1999 Yaris with power steering. I think it's different to the 1.3 L

[Woody27]

O right surely still not that hard? basically undo Battery, loosen belt and unplug and unbolt alternator?

[new yaris owner]

O right surely still not that hard? basically undo battery, loosen belt and unplug and unbolt alternator?

I wish.

The alternator is mounted on the rear of the engine so is quite difficult to remove from the car without having to dismantle some parts of the car you really don’t want to.

I've now done the job. So for the benefit of any other poor DIY sole attempting to do it I’ve posted some tips further below.

But first some notes about diagnosing the fault in the first place ! Because it is unusual, and can lead to incorrect diagnosis, resulting in costly/time consuming action.

This is for a 1999 Jap built Yaris 1.0 litre manual, with power steering , no a/c.

From cold start. Engine initially started, but immediately seemed unusual. Seemed to lack power at idle. When I increased throttle, whilst in neutral, engine stalled. Tried to re-start, starter motor cranked really slowly. Similar symptoms to a flat Battery. After many attempts eventually the Battery was flat.

So my immediate thoughts were a flat Battery was the problem. Charged the battery overnight. Went to start. But same problem. Starter cranked really slowly, not enough to fire up the engine. (Thus far the symptoms could point to a faulty battery, starter motor, bad electrical connection.)

I took a look at the engine whilst trying to start it. I noticed that the crankshaft pulley, (the bottom pulley), was rotating slightly but the alternator belt was not moving at all.

Ahah I thought, the alternator belt is slipping. But the belt tension was OK. So this was unlikely.

So, in hindsight, luckily, I decided one of the pulleys that the alternator belt wraps around must be jammed. But which one ?

I decided to slacken the alternator belt so I could identify which one.

This is relatively easy. Has to be loosened from under the car.

Adjusting/Loosening the alternator belt:

1. Raise the vehicle so you can clamber underneath. I used the car jack, or drive the vehicle up onto ramps. But remember to apply the handbrake fully, chock the rear wheels and support the weight of the vehicle independently, best done with axle stands.

2. Remove the plastic left lower cover panel so you can access the left side of the engine from underneath.

3. Loosen the lower alternator lower pivot bolt.

4. From the top of the engine, loosen the lockbolt at the top of the alternator and the bolt supporting the power steering pipe work.

5. Unscrew the adjuster bolt (the very long bolt visible over the top of the alternator)

6. Pull the alternator fully towards the engine, which should slacken the belt, and enable you to remove the belt. Remove the belt from the pulleys noting there original formation.

7. You should now be able to rotate each pulley by hand. And identify if any are jammed or sticking.

This is where I found the alternator was jammed solid.

So how much does a new/reconditioned alternator cost ? Shock horror, I was quoted £180 +vat from several sources. If you can afford it, I’d advise getting it replaced by a reputable garage as replacing it yourself is not for the short tempered ! You will also need a decent set of spanners and sockets, axle stands. And I would strongly recommend getting a Haynes manual.

So, reluctant to support my local garage keep alive fund, who would charge me about £500 for this, I decided to DIY.

I searched on the internet and got about twenty quotes from breakers yards who all came in at about £40 + £10 delivery + VAT obviously for a used alternator. One was local and said it was from a low mileage car.

This is obviously a risk, but considering the fault is rare, and the saving considerable, it was a risk I was happy to take. It was delivered next day.

Replacing the alternator:

Assuming the above steps have been carried out:

8. Disconnect the negative wires from the battery.

9. You need to remove the two cables from the alternator, one is secured with a nut and protected by a plastic cap. I found it easier to remove this one from above. Depends how big you hands are and how long your arms are !. The other cable is plugged in and I found it easier to remove from underneath. One of the cables is tied to the alternator casing. Just cut through the cable tie.

10. Remove the adjuster bolt and assemble from the upper alternator.

11. Remove the lower alternator pivot bolt. (This took me the longest time, as it was extremely tight, so be prepared. I used a hammer and smaller bolt to bash it through the engine mounting lugs.)

12. Have a rest you’re about half way there !

13. You should be able to move the alternator away from the engine, slightly !.

14. The alternator cannot be removed from the top of the car, unless you want to remove the inlet manifold which is not advisable. You may try all sorts of ways to remove it, but you won’t be able to, unless you do some serious dismantling of the car, or buy yourself a Haynes manual, where it tells you how best to do it. !

15. The only way I could remove it was to maneuver it over the top of the exhaust pipe through a tiny gap towards the back of the car. I could only do it with the pulley facing the front and with the alternator upside down. You will need to remove the exhaust sensor in the top of the exhaust pipe just below the handbrake lever to allow the alternator to pass very tightly past the exhaust and away from the car.

16. This was probably the most difficult part of the job. So have a deserved rest.

17. Fitting the replacement alternator is a reversal of the above and I found this quite easy.

The following steps describe how to remove and replace the alternator belt. This only needs to be done if there are visible signs of wear, like cracks in it, or it has done 40,000 miles, the manufacturer’s advised replacement interval.

Obtaining a new alternator belt can be an experience. I phoned two local Toyota franchises and neither could identify the correct part as they had a choice of two to choose from even though they had my vehicle VIN number. So I got the part from a local auto-factors for about £14. The part was a Gates Micro-V XF part No. 4PK1708

18. You will need to support the weight of the engine and remove the engine mounting to do this. But first jack the front of the vehicle up as you may have to lower the car a bit to refit the engine mounting. Use an axle stand or similar, place a thick piece of wood between the stand and the engine sump, so they support the weight of the engine without damaging the sump.

19. Remove the three bolts securing the engine mount to the body work. Remove the mounting center bolt from underneath the car. From the top, remove the three bolts securing the mount to the engine.

20. You should now be able to remove the old belt and replace the new one.

Wrap the new belt around the pulleys loosely. And replace all the engine mounting bolts.

21. Adjust the slack by adjusting the alternator adjuster bolt. And rotate the engine manually by rotating the engine crankshaft pulley with a large spanner or socket set to ensure the belt grooves settle in the pulleys.

22. Adjust the belt tension to the specification. i.e should have about a thumbs thickness of play at the belts longest span between two pulleys. Do not adjust the tension to tight as you will destroy the alternator bearings and have to do the whole job over again ! Better slightly loose than too tight. The belt should be re-tensioned after approx 1000 miles.

And that’s about it. Easy eh !

[ad21ca]

Thanks, very helpful, followed the steps and it worked, but i removed the exhaust, was easier

[overtakinjoe]

sorry mine is a 2003 yaris 1.0L , love all you have wrote , ( woody27 ) , BUT ? my attempt so far ! has ground to a stop .

because my alternator is Original supply ? now ( 152 k Mileage ) bearing seized BUT ( bottom long bolt is seized )

to the engine casting ( middle bit ) the two aluminium outer lug's are free turning on the the long bolt , that is seized to the middle

part of engine casting ? I hope this is understood , now for the problem itself , the large bolt ( head) on O/side has snapped OFF ???

( job done by my very strong SON inlaw ) AS STRONG AS THE HULK ! regular as clockwork he snap's spanners / nuts and other things you would'nt believe ( this is the honest truth )

Any suggestions ( how to get this bolt out ) ?????? because I'm stumped as where to go from here

MAYBE I SHOULD CALL THE AA

[TomdeGuerre]

sorry mine is a 2003 yaris 1.0L , love all you have wrote , ( woody27 ) , BUT ? my attempt so far ! has ground to a stop .

because my alternator is Original supply ? now ( 152 k Mileage ) bearing seized BUT ( bottom long bolt is seized )

to the engine casting ( middle bit ) the two aluminium outer lug's are free turning on the the long bolt , that is seized to the middle

part of engine casting ? I hope this is understood , now for the problem itself , the large bolt ( head) on O/side has snapped OFF ???

( job done by my very strong SON inlaw ) AS STRONG AS THE HULK ! regular as clockwork he snap's spanners / nuts and other things you would'nt believe ( this is the honest truth )

Any suggestions ( how to get this bolt out ) ?????? because I'm stumped as where to go from here

MAYBE I SHOULD CALL THE AA

Seems like you're in a bit of a pickle then John although your son in law sounds like a handy bloke to have in the pub if a few skulls need cracked. If the head has snapped off the long bolt then can you get in to remove the bolts that hold the alternator mounting bracket on to the engine? You might need to get the S-I-L to rip the engine out of its mounts a wee bit to get at them!

Only other thing i can think of would be to get in with a Dremel saw and cut through the bolt in two places to let you get the alternator out and then remove the bracket. If you can't get a saw in can you get in with a drill and drill through the bolt in ever increasing sizes until you can eventually remove it.

I don't know your engine, does it look like the attached? Alternator highlighted by red arrow.

[MEP's Yaris GS]

When our OEM alternator seized on our 1.0 Yaris we had the same issue with the big bolt, was spinning, but couldn't for the life of me get it out. Sent the car to my mechanic, and even with it in the air with easy access it took him about an hour to get it out!!

Luckily when it went a 2nd time it was really easy as was only about 2.5 years down the line.