rev counter problem

[knighttemplar]

Can anybody offer a newbie some assitance please? I recently had a 123 ignition fitted by a local mechanic but for some reason my rev counter doesn't work now. Is it down to one of the wires not being connected properly, even though I don't have a problem with the running of the car?

Can somebody also tell me if I have to replace the whole of the driver's window body, if I've found that some of the teeth inside the drivers door have broken away. At the moment I am having difficulty winding the door window to it's full position. Any help guys would be greatly appreciated.

[capt jack]

123 Ignition and older rev counters are not compatible, and I'm surprised the guy who fitted the igniton didn't warn you.

It's possible to have the rev counter upgraded, and there are specialists who can do this for you.

A web search should turn this up. Suggest you start at the 123 web site.

The window mechanism can be removed from the door, and repaired. Knuckle grazing but not too difficult.

Is the window difficult to get up or down?

Cheers

Jack

[Ron Kwas]

Guys;

The " aren't compatible" answer is akin to "impossible", and without further info or an explaination, I just cant accept that...maybe some qualified individual or 123 will chime in with details and we can work out a way to get the tach operational...I bet a solution could be engineered...

...no such thing as can't do...!

[capt jack]

Hi Guys

Quote from my original answer:

It's possible to have the rev counter upgraded, and there are specialists who can do this for you.

Quote from FAQ on 123 website

My tachometer /rev counter is driven directly from my mechanical distributor, so I cannot use a 123?

Sure you can! JDO-instruments ( www.jdo1.com ) and CASU ( www.casu.nl ) are specialists in the repair of classic car instruments. When you replace your distributor, you can send your mechanical rev,counter to these guys, for conversion to an all-electronic instrument keeping the classic look

As you say Ron, there's no such thing as can't!

Cheers

Jack

[asneddon]

What type of rev counter are we talking about? There are three different ones.

Rev1: which is early Jensen, black box in front of the radiator.
Rev2: about '63 until the fake wood dash came out. Takes a coil off the negative feed from the coil under a clamp on the back.
Rev3: Fake wood dash type. Bullet connectors on the back to pretty much replicate the Rev2 type. Cheaper for Smiths to make.

If its Rev1, then I think its current sensing, and you may as well look for a second hand one. If its rev2 or 3 then you should just be able to hook up the induction loop around the positive side of the coil rather than the negative (I guess). That would involve cutting off the armoured shielding from the coil to the ignition switch though.

I still dont have a working rev counter, so you might want to ignore me. There is a bit of a thread on the Wants forum about all this though:

http://www.volvoforums.org.uk/showthread.php?t=71889

[ClassicVolvoShop]

I do not at all see, why it shouldn't work just as usual.. ??

I admit that I have only looked on the 123ignition website for the first time today - and found the installation PDF for the B18/20 unit.

In the manual - there's a BLACK wire that's surposed to go on the - (minus/ground) terminal on the coil.

The accessorie rev. counters uses this ground connection to count - so why not just cut the BLACK wire and throw in between the rev. counter (usually WHITE) wires??..

Have I missed something?

Added:
According to wirring diagrams for the 1800 series - the rev. counter is put in between the WHITE cable from "-" (ground/minus) to the distributor.
According to the 123ignition manual, the 123ignition distributor and the coil is to be connected by a BLACK cable/wire.

As far as I see, the 123ignition does not require any special "terms" for the BLACK wire - so solution is simple: Cut the BLACK wire - and reconnect it with the "old" WHITE wires (going in/out and through firewall).

I see no reason for any "modifications"??..


Final edit:

Search for 1800S on the 123igitinion's own forum (!!)

http://www.123ignition.nl/forum/read.php?f=3&i=740&t=740#reply_740

As said - loop the BLACK wire with the "old" WHITE wires.

http://i97.photobucket.com/albums/l236/taffy1967/Mini%20Stuff/modules.jpg

[knighttemplar]

Thanks guys for the information. The mechanic has since retired, and now works from home. He simply followed the instructions to its fitting I'm afraid. I went back to him to say my rev counter doesn't work but he tried to tell me it wasn't working when he got it which it was. I tried playing with the wires myself, but wondered if I may damage the 123 in the process. The car is a 1971 1800E.

[JP 1800]

I had a problem with my tachometer too, so I made a electronic box to replace the internal circuits which are prone to failure. So my new system is voltage sensing and also adjustable for calibration

[asneddon]

Was that a kit? I've been trying to sort mine out fir a while.

[Mike Arnold]

I fitted a Smiths rev counter to my 122 and then put electronic ignition on it. Rev counter stopped working (and massive radio interference). After much head scratching I realised that the current kick that an electonic ignition provides was not enough to activate the rev counter. I built a small electronic unit to turn a voltage spike (from the coil primary) into a current pulse for the rev counter.

If you are confident with electronic components it is not a problem but most people are not.

[JP 1800]

I bought a modern small tachometer ( voltage sensing type ) and I took the circuit board from inside it. I opened the smiths tach ( A right PITA ) and bypassed the old electronics and wired up the new circuit board. It is quite simple to do.

[asneddon]

Thanks. I just bought a small (52mm) one today. A previous owner has already cut a hole in the dash in front of the passenger so I will stick it there for a while. I'm not sure if its going to be adjustable to take into account the difference in friction / different degrees between rpms etc. I guess once I get sick of it I can pull it apart and see how it looks (Ive already disected 3 volvo rev counters and no luck so far).

[JP 1800]

Thanks. I just bought a small (52mm) one today. A previous owner has already cut a hole in the dash in front of the passenger so I will stick it there for a while. I'm not sure if its going to be adjustable to take into account the difference in friction / different degrees between rpms etc. I guess once I get sick of it I can pull it apart and see how it looks (Ive already disected 3 volvo rev counters and no luck so far).

Do you have a spare "glass" for the rev counter as I cracked mine, I can then have an excuse to open mine again and take some photos to show you how i repaird mine.

[asneddon]

The non-working rev 2 in the car at the moment has a small craze, the rev 1 on my shelf has a good glass, but the chrome surround is all scratched up. the other one I have is a rev 3 (black surround/wooden dash type) which is probably no good to you.

I figured when I pull mine apart I would use the good chrome from the rev2 and the good glass from the rev1. I've also painted up the rev1 so it looks as good as new (except for the chrome of course). That might be some time off though. I spent weeks fiddling with bloody rev counters and Im a bit sick of them at the moment. The thread is in the Wanted forum for some reason.

I do know that Charlie at classic volvos (Oxford) has at least one more rev1 in his shed though. From memory it was a bit rusty, but the glass might still be in good condition. if you want I can pop in there sometime next week to have a look. I need to get some other bits off him soon anyway.

[JP 1800]

That would be great, thanks