vdo tach repair

[BrendAn]

i have a vdo tacho that is not working in the jabiru. it runs off a sensor on the flywheel.

it has the inbuilt hour meter as well.

Can anyone tell me if it can be repaired. it doesn't power up.

i  would hate to throw it out if its just a dry solder joint or something simple.

a new one is $440 which does not bother me. its the loss of the recorded hours i would like to save.

[T510]

I have used Howard Instruments for VDO gauge repairs in the past. 

 

They can be a little caustic and I know a few people who have had personality clashes with them but in my experience they do good work at a fair price.

[onetrack]

There was a previous discussion around this same problem. The OP found a repairer in Adelaide.

 

https://www.aircraftpilots.com/forums/topic/38510-vdo-rev-counter-hour-meter/#comment-531538

 

[BrendAn]

57 minutes ago, T510 said:

I have used Howard Instruments for VDO gauge repairs in the past. 

 

They can be a little caustic and I know a few people who have had personality clashes with them but in my experience they do good work at a fair price.

i notice on this one the needle will flick up for a second when you apply power then its dead. and the hours don't come on. do think it might be just a power problem.

[skippydiesel]

2 hours ago, BrendAn said:

i notice on this one the needle will flick up for a second when you apply power then its dead. and the hours don't come on. do think it might be just a power problem.

First off - Check cables for continuity and the that all joins are clean & secure . Pay special attention to the earth (-) return.

 

After the above, if it's still dead,  you may need an electronics technician. Good luck! 😈

 

[Thruster88]

A Jab 55 here is having electrical issues, has been diagnosed as a bad fuse block. Tests fine until put under load.

[BrendAn]

I have the tacho on the bench. I get nothing when I put power direct to the terminals. The problem is in the tacho itself.

[Neil_S]

20 hours ago, T510 said:

I have used Howard Instruments for VDO gauge repairs in the past. 

 

 

I have used Howard Instruments for VDO tacho repairs too. They did a good job and charged a reasonable price.

(Their shop is an Aladdin's Cave of instruments old and new!)

 

Cheers,

Neil

[BrendAn]

36 minutes ago, Neil_S said:

I have used Howard Instruments for VDO tacho repairs too. They did a good job and charged a reasonable price.

(Their shop is an Aladdin's Cave of instruments old and new!)

 

Cheers,

Neil

Thanks niel

[skippydiesel]

On 14/06/2026 at 5:19 PM, BrendAn said:

I have the tacho on the bench. I get nothing when I put power direct to the terminals. The problem is in the tacho itself.

Not an electronics person;

My gut feeling is that just connecting the tacho to power, on the bench, is not a diagnostic action.

To find out if the tacho is working you will need to send a pulse/signal (as from the flywheel sensor). 

You will first have to assertion that the sensor (Hall Effect/Photo/Lazer) is working as expected - probably the easiest way is to temporarily wire in a "know to be working" tacho.

If the loner tacho works, then suspect your tacho but first follow my advice (above) on making sure you have good connections😈

[BrendAn]

10 minutes ago, skippydiesel said:

Not an electronics person;

My gut feeling is that just connecting the tacho to power, on the bench, is not a diagnostic action.

To find out if the tacho is working you will need to send a pulse/signal (as from the flywheel sensor). 

You will first have to assertion that the sensor (Hall Effect/Photo/Lazer) is working as expected - probably the easiest way is to temporarily wire in a "know to be working" tacho.

If the loner tacho works, then suspect your tacho but first follow my advice (above) on making sure you have good connections😈

yes. but i thought putting power and earth to it should light up the hour meter. maybe not. i don't know anything about it.

i think i will send it off and get it looked at. 

[facthunter]

Some work off an ignition lead by inductance. I doubt that would take kindly to a direct electrical source. Some Hobbs Meters work on electric power put through a U/C micro switch to Just measure AIR time. I have a good one IF anyone wants it.  Nev

[skippydiesel]

2 hours ago, BrendAn said:

yes. but i thought putting power and earth to it should light up the hour meter. maybe not. i don't know anything about it.

i think i will send it off and get it looked at. 

Give yourself the potential to save a few $$ - Check your sensor is working before, sending the Tacho for an  expensive assessment😈

[BrendAn]

23 hours ago, facthunter said:

Some work off an ignition lead by inductance. I doubt that would take kindly to a direct electrical source. Some Hobbs Meters work on electric power put through a U/C micro switch to Just measure AIR time. I have a good one IF anyone wants it.  Nev

the vdo tach has a hall effect type pickup.  the tach itself has pos and neg terminals and a sensor terminal. i would have thought putting power and earth to it would light up the hourmeter but as i said, i know nothing.

[BrendAn]

i just found howard instruments right here in Hiedleberg. i will take it to them.

[skippydiesel]

2 hours ago, BrendAn said:

i just found howard instruments right here in Hiedleberg. i will take it to them.

Let us know how things "pan out"😈

[BrendAn]

Just now, skippydiesel said:

Let us know how things "pan out"😈

will do

[BrendAn]

On 16/06/2026 at 8:39 PM, skippydiesel said:

Let us know how things "pan out"😈

spoke to howards yesterday.  they are in the midst of moving to another building in Heidelberg hgts .

the lady said bring the tacho in in 2weeks and they should be able to fix it. she also thinks its just a power issue because the hourmeter doesn't come on.

[BurnieM]

Unless you let the smoke out of the box.

 

[T510]

On 23/06/2026 at 8:51 PM, BrendAn said:

spoke to howards yesterday.  they are in the midst of moving to another building in Heidelberg hgts .

the lady said bring the tacho in in 2weeks and they should be able to fix it. she also thinks its just a power issue because the hourmeter doesn't come on.

How did you go with this Brendan?

[BrendAn]

2 hours ago, T510 said:

How did you go with this Brendan?

hi mate. no good so far. i rang yesterday and they said they couldn't possibly look at it til after the end of the month, after she had already told me they would look at it after 2 weeks.

i decided to just get a new one from jabiru rather than wait and be told the same thing again.  they are swamped with work at howards.

jabiru can now get the hours programmed into the new tacho too which is something i wanted to do as well.

 

 

 

[T510]

That's disappointing, It's understandable that they are busy but they could at least give you an accurate timeframe.

 

 

[facthunter]

How could you do that with a large backlog of work and not being sure till you start on each job how much work is involved or what parts are required and what can be repaired and can't be. ?  The fact they have a lot of work means they are trusted. You're lucky to get people who are still doing this stuff at all.  It's probably Not the way to make Millions either.  In this world the retailer often makes more money per Item /article than the Manufacturer does.  Nev

[BrendAn]

2 hours ago, facthunter said:

How could you do that with a large backlog of work and not being sure till you start on each job how much work is involved or what parts are required and what can be repaired and can't be. ?  The fact they have a lot of work means they are trusted. You're lucky to get people who are still doing this stuff at all.  It's probably Not the way to make Millions either.  In this world the retailer often makes more money per Item /article than the Manufacturer does.  Nev

they are the vdo repair agents.

you don't tell someone to come back in 2 weeks then in 2 weeks tell them the end of the month.

i will buy a new tacho but i think i will still drop the old one off . see if they can fix that one so i have a spare.

 

[facthunter]

 I did explain the circumstances as I  see them.  I've run repair Businesses and know of many others where there Has been a  waiting list or indefinite  deferment. There is a limited capacity to handle stuff sitting around and keeping track of it. That all detracts from getting on with what you already have there already.  No small business can be expected to cope with an unanticipated rush. Nev