johna's automotive blog

Testing and repairing the Holden Commodore VT, VX, VY climate control fan amplifier

2026-06-19T12:00:00+10:00

This advice is for Holden Commodore VT, VX and VY models with climate control and this specific module in my photos, called an amplifier, or often called a fan resistor.

Common faults include the interior fan not working at all, not working except at the highest speed, or the fan running flat out even with the key out.

Before you can test this part you need to get it out. There are probably better instructions online and videos on YouTube, but the basic instructions are as follows:

1. Open the glove box and pull out the plastic piece that acts as the hinge on the right (driver's ) side of the inside of the glove box.
2. The globe box should now come out. You may need to bend in the right hand piece that stops the glove box from opening too far.
3. There are around 15 screws around the outside of the glove box opening. There are two types of screws so remember where they go.
4. The piece on the left side of the glove box will now come off.
5. The horizontal piece underneath the glove box area is held on by a couple of clips and can pull off downwards.
6. The plastic on the side of the centre console can be maneuvered downwards and out of the way.
7. The amplifier is located behind the glovebox opening on the right side. You should be able to see the electrical plug and the white part of it.
8. You now have access to one of the two screws that holds on the amplifier -- the lower one. Unscrew that.
9. Now pull out the plastic piece that forms the back of the glovebox opening.
10. The amplifier can be unplugged and the top screw removed and then it can be maneuvered out.

Once you have the amplifier out, confirm that it looks the same as my photos otherwise this advice won't be of help to you.

You are likely to have one of two problems (or both): bad solder joints or a bad transistor.

If you have a multimeter you can test the transistor. Set it to continuity mode where it beeps when the probes touch each other. This is a very basic test but usually enough to identify a bad transistor. On the side of the electrical connector with the two pins, touch the leads on these two pins. It doesn't matter which is positive and which is negative. If you hear a beep then your transistor is faulty.

To check for bad solder joints you need to pull the amplifier apart. The white plastic part is clipped to the metal heatsink. You need to unclip both sides -- a small flat screwdriver can lever it out on both sides. See my photo. Make note of which way it was attached.

Now you can see the circuit board and you will more than likely see that some of the solder joints look not so good due to years of heat and usage. The two transistor pins are the most likely ones to need work.

These amplifiers are usually at least $50 second hand, or you can but after market new ones for $120 or much more. The new ones look different and I have no experience with them. You should also be able to repair yours inexpensively if you have a soldering iron and some time.

If your transistor measured okay then you can resolder any suspicious solder joints. You may find that it's not so easy to resolder unless you use a lot of heat, add some fresh solder and flux if you have it.

If your transistor is bad then you have a choice to make. Replace the transistor or replace the whole amplifier. If you buy a transistor locally you may need to spend $20 or $30 or more for a new transistor and you will probably need a new insulator pad as it will likely tear apart when the transistor is removed. If you can wait two weeks you can buy a couple of transistors and lots of insulators on Aliexpress.com for less than $10.

To replace the transistor you will need to do some more disassembly. First unscrew the two screws on each side of the heatsink and remove the centre heatsink part. Then you can unscrew the transistor from the top and then desolder and remove it. Note that early models use one of the screws to electrically connect the top of the transistor to the circuit board and later models have a extra copper piece for this purpose. For early models you need to resolder the screw to the board (requires lots of heat).

Part numbers you might need:

• The original Holden part number is 92162703 (may vary)
• They are sometimes labelled 06-1373 or 06-21373 (may vary)
• The transistor is MJ11032 or MJ11032G, TO-3 package
• The insulator pad is a TO-3 type, usually silicon or mica

What to do if your Commodore VT/VX/VY door won't open

2025-03-17T12:00:00+10:00

On our 2002 VX Berlina, we were recently stuck in the driver's seat because the door would not open. If you are able-bodied this isn't a big problem as you can climb out another way, but that might not be possible for some people.

This is the scenario we faced. The door can not be opened using the inside or the outside handles. The doors appear to lock and unlock normally and the other doors work as usual. Both the inside and outside handles feel to be connected and operating (they are not loose and floppy), but the door just won't open.

After some investigation, I believe the problem here is that part of the door latch mechanism has worn out and won't move in to the position it needs to for either of the handles to work.

Here's what we did to open the driver's door, although this should also apply to the front passenger door.

You need to get access to the door latch mechanism which is inside the door, of course, and behind the door card which is almost impossible to remove with the door stuck closed.

However it is possible to gain a little access by removing a few of the screws.

Remove the lower B-pillar trim by prying out from the top. This gives just enough access to remove one screw at the rear of the door card.

Remove the lock knob by first prying out the red locking piece. Undo the screw behind it.

Remove the decorative cover from the inside door handle and remove the screw. Then there is another screw behind the door handle that should be removed.

Remove the inside mirror cover by pulling it straight out.

Now with a certain level of violence you can pull up and outward the rear top of the door card.

Then you can separate the plastic seal and gain access to the door latch mechanism and actuator.

The only way we could get the door open was to feel where the outside door handle rod connects to the mechanism and pull this upward (part A in the picture below). That was enough for it to get in a position where it could activate the door latch. This is not as easy as it sounds as you can't see that far inside the door and there is a plastic cover on the top of the door lock mechanism. You may find it easier if you pull this cover off (requires force and you will likely break it but you will probably be replacing the whole unit anyway).

The other option is to rotate part of the mechanism anti-clockwise, if you can reach it (part D in the picture).

Familiarise yourself with the photos to see where these parts are and what you are feeling inside the door for. They will also help to show where the various rods attach when replacing the lock mechanism and actuator.

Hopefully you can then pull the outer handle and open the door.

The part that caused this problem for us was the rotating part. It appears that it wore out enough that it either could rotate further than it should, or maybe the spring that returns it to the correct position was no longer strong enough. It was very loose on the shaft compared to the replacement part.

The solution here is to replace the whole mechanism. A new one is around A$300 or second hand ones can be bought for under A$100 on eBay.

PS. We had called out the NRMA hoping they would know a trick to get the door open but they couldn't get it open.

A - Outer door handle rod sits in here. This is the part you can pull upwards to get it back in position. When installing, you need to make sure the rod aligns to this hole first.

B - Inside door handle rod attaches here.

C - Outside door key lock rod attaches here.

D - The cause of this problem. When worn out, this can rotate too far clockwise.

E - Inside door lock. No need to remove this, but take note of how it is routed and it can be a pain to line back up when installing.

(Actuator solenoid removed for photos but does not need to be removed)

My first car

2024-03-11T12:00:00+10:00

Although I had been very interested in cars in my early teens, I wasn't a car enthusiast when it came time to buy my first car, and I didn't know much about cars.

I got my license on a weekday and went car shopping that weekend. I had only driven cars with an automatic transmission so that's what I planned to buy.

I can't remember all the cars that I looked at that weekend with my father and sister, but I remember a yellow 1970's "Mustang-style" Toyota Celica which ended up having a bit of rust. Then at some point I looked at a VC Holden Commodore.

As I said, I didn't know much about cars and just wanted to buy one straight away so that I didn't have to rely on borrowing a car. I probably didn't fully understand the difference between a four-cylinder and a six-cylinder Commodore.

The VC seemed okay to us non-car people, so I bought it. I remember it being somewhere around $5,000. Surprisingly they took a cheque and I was able to drive it away that weekend. Times were different then.

So the beige-coloured Commodore was a 1.9-litre four-cylinder with automatic transmission. These are known for being painfully slow. Not that 58 kW stopped me from driving fast. I remember driving plenty fast at every opportunity. Does 140 km/h counts as being fast? It probably does if it's in a 60 km/h zone.

Together, the Commodore and I explored the world, transported friends, and introduced me to fast night drives on twisty desolate roads through bushland. I remember more than once understeering off the road, not that I knew what it was called at the time.

Aside from constant alternator problems, the car was reliable. At some point the car needed an automatic transmission service and I remember the mechanic warning me how much faster and more dangerous it was going to be after the service as he had found some issues preventing it from delivering full power to the back wheel. I doubt this has ever been said of a four-cylinder Commodore before, and although I was excited at the thought or more performance, I don't think I noticed any difference at all.

Now that I had a car, I was becoming more interested in cars, and after about a year of ownership I traded the Commodore in on a first-generation Honda Prelude -- a car with similar performance, but one which had many "quirks and features".

Holden Commodore (VE) 2006-2013 Review

2021-03-27T12:00:00+10:00

The Alloytech V6 engine can suffer from timing chain problems that requires costly replacement.

Image credit: OSX, Public domain, via Wikimedia Commons

Holden Commodore (VT/VX/VY/VZ) 1997-2007 Review

2021-03-27T12:00:00+10:00

Although build quality is not great and these models are not without common problems, parts are plentiful and cheap.

The old-tech Ecotec V6 engine fitted to the VT, VX and VY is strong and long-lived, and can survive poor maintenance better than most. Fuel economy is not great.

The Alloytech V6 engine replaced the Ecotec for the VZ series. The new engine can suffer from timing chain problems that requires costly replacement.

The long-lived 5.0-litre Holden V8 was replaced with a larger 5.7-litre Chevrolet-sourced V8 when the VT series II model was introduced. The new engine had issues with oil consumption and other problems.

Image credit: OSX, Public domain, via Wikimedia Commons

Holden Commodore VT V6 fuel filter replacement

2015-06-17T12:00:00+10:00

I recently replaced the fuel filter on our 1998 Holden Commodore Acclaim with the 3.8 litre V6 engine. I found that the instructions I had found online for how to remove the fuel pipes did not work for me so here are some instructions for how I did it.

Before you start on this job you should relieve fuel pressure. I did this by leaving the car running and then pulling out the fuel pump fuse.

Firstly, if you aren't sure where the fuel filter is located, it is accessible from underneath and behind the car, just next to the differential and on the right side of the car.

I backed the car up on to ramps so that there was plenty of room to work in, but you don't necessarily need to lift the car at all.

The filter is held in place with a plastic clip which is easy to remove, but you are probably best leaving that until after the hoses have been removed.

To remove the hoses some people say to squeeze them, possibly using pliers, and that they break easy. I found that no amount of squeezing would release them.

Instead I used two small flat screwdrivers and inserted them into the two larger holes on each side of the hose-end clip. I inserted them in the direction of the filter end of the hose/clip. With just a little levering of both screwdrivers and a push towards the filter then pull back from the filter action they came out very easily and without breakage.

Before you take it out make note of which direction the filter is installed.

To avoid as much fuel leakage as possible, on the new filter leave one of the plugs on and as you take off one end of the hose plug it straight into the new filter, then put the plug that came with the new filter on the old filter. Then take off the other hose end and connect to the new filter and re-clip it to the car.

It's a simple job that should take only a few minutes, depending on how long it takes you to work out the clips.