328 Tach Reads Low Sometimes

Sometimes erratic gauages are a symptom of a bad electrical ground on the gauge itself.

 

I have the exact same problem on my 89 328 but, mine always reads low. The highest it will register is about 4000 rpm when its at 7000. I sent the tach off and had it checked, it came back good. I've also changed my digiplex unit, cleaned the tack sensor, and switched it with the TDC sensor (same sensor), none of this had any effect. I think i've checked the ground, but I can check again. PLEASE LET ME KN0W IF YOU FIND THE ANSWER.

 

Mine did the exact same thing. It's a common defect. Sent the tach to Palo Alto Speedometer and they fixed it for $159.00 with a 1 day turnaround. They have a website but I don't have the link. Sorry.

 

My car does exactly the same, a technician guaranteed to me that everything is well.


Take out the rev counter is very easy.
Removes the 4 lamps with care, and inside you see 4 screws, but I recommend to you that before you make a simple test: disassembles the battery and recharge, it reviews the front electrical ground connector, and the tips of connection of the battery, verifies that it is clean and strong.
Whenever I do this, my rev counter returns to work well.

Attached photo copied of http://parts.ferrari.co.uk

I request excuses by my badly writing English.

Greetings

Alfredo.

 

This is a very common problem with the 3.2 motor cars. I'm 99 percent sure you need your tach repaired. Follow the removal instructions provided by others, and you should be good to go. I also sent mine to Palo Alto Speedometer. Around $150 and four day turn around...

Dave

 

You might want to get a second opinion, and have another shop test your tach. Only because this is such a common problem on the 3.2 cars...

 

Another thing: the mechanism of 328 tach is just as the one that takes the Alfa Romeo 75, such component.

Alfredo

 

Good point here; do check and clean all the connections, and ensure the grounds are good. I have heard others say (these were 308's I think) that they were able to fix their tachs by cleaning or adding a new ground wire. I checked and cleaned mine, and even tried adding an additional ground, but it was no help. Having it repaired was the only proper fix for me.[/QUOTE]

.
Are we referring to the battery earth or the earth wire on the tach itself ?

Skin

 

Hi.

We have NOS tachos in stock, #125947, retail $322.76. Orders placed thru the Ferrari Owners' Site, www.owners.ferrari.com will receive 50% discount on this unit (not shipping & duty of course) if ordered on the website between now and Monday morning !

Any good ?

 

i have had this same problem since i got my '87 328 gts
9/2003. tach reads less than or approx = to 1/2 the engine
speed. sometimes. a few times it has shown 6-7000rpm,
but mostly 1/2 that amount. WHY? these cars are almost 20 years
old. does no one know why? there must be a known fix. please share.

bob

 

Jeff, I just ordered 125947 from ferrari uk, it did not show the discounted price. Will it be billed at the discounted price? Also on the web site it showed a revcounter head part, do I need this to replace the tach?
Thanks, Chuck

 

Bob,
You must have missed my previous post in this thread. It is a VERY common problem, and easily repaired at Palo Alto Speedometer http://www.paspeedo.com/

They tell me that there is a component on the circuit board that fails. They will replace it, test and warranty for one year for around $150 plus shipping. Mine was fixed a little over one year ago. Continues to work fine.

That or get the brand new one from Ferrari UK. Either way, this will correct the problem. I tried cleaning grounds, and putting contact enhancer on all the connections, and this improved things, but never fixed it. Having the tach repaired, fixed it for good.

Regards,
Dave

 

Hi Chuck.

We will discount the order when we recieve it our end, no worries.

The only part you need is #125947.

Regards.

 

Thanks Jeff, I ordered that part and a oil rad from the owners site on sat night. I suppose I will get confirmation and delivery info on Monday, is this correct?
Thanks again
Chuck

 

Chuck, the next thing you'll hear will be a total and a request to charge your card.

Best regards.

JH

 

Jeff,

your great supply has convinced to me,

I also I have ordered one.


Regards.


Alfredo

 

I hope that you guys that have ordered new tachs from the fine folks at Ferrari UK will report back on whether this fixes your problem. I am confidently betting that all will be well shortly!

Regards,
Dave

 

Count me in, too, on the Tach! I hope 11:48am Monday Morning US Mountain Time still counts as "Monday Morning!"


--Mike

 

Ordered mine from Ferrari UK this morning as well. I'm hoping that I made the Monday morning cut. It was definitely still morning here.

 

I was wondering if anyone had received confirmation from ferrari UK yet? I have never ordered from them before and I am not sure of the normal wait time on confirmation emails or delivery dates. Thanks, Chuck

 

Got my email confirmation from Jeff Howe yesterday. The shipping is always surprisingly rapid as well.