digital dash in a 1990 Beretta problems

whitetalonb16g · Post by **whitetalonb16g** » Sat Jul 15, 2006 4:55 pm

Hey can anyone give me a heads up on whats going on with my digital dash swap. My old analog cluster was on the brink and so I decided to replace it with a digital one from a 1988/89 Beretta GTU 2.8L I found in the junkyard.

I took the dash and the entire interior wiring harness from the donor car and installed it into my car which is a 1990 Beretta GT 3.1L.

I plugged in all the connectors and everything is working except for my fuel gauge and the lights on the right hand side of the cluster that shows the trip, odometer, temp, etc etc. I can see the numbers but its not lit up, Im beleiving that to be a burnt out bulb on the bottom, BUT needless to say that isn't bothering me.

WHAT is really annoying me is that I have no idea what my gas gauge is reading. Prior to installing the digital dash I filled up my gas tank to the max and it is still reading EMPTY.

Is there something I did wrong or something that I need to fix. Any help appreciated ASAP since my car is apart for 1day now and I need it for work everyday.

Thanks in advance!

1988GTU · Post by **1988GTU** » Sat Jul 15, 2006 7:26 pm

So your fuel guage didn't work before or after the install of the replacement cluster?

If this is correct, then your float in the tank is on the brink.

whitetalonb16g · Post by **whitetalonb16g** » Sat Jul 15, 2006 11:48 pm

no maybe i worded it wrong, My fuel worked properly on the old setup, the only thing wrong with the old cluster was the tach and mph reading abnormally incorrect.

The no gas situation started to occur once i swapped the digital dash in. If I took the old harness (which I've done) and reconnected the old cluster (done) fuel gauge works.

Thanks for the help.

1988GTU · Post by **1988GTU** » Sun Jul 16, 2006 12:39 am

I would suspect a faulty replacement cluster...
If you could find another one to try I'd rec. to do so.
Taking it (the clusters) apart to swap stuff is out of the question.

whitetalonb16g · Post by **whitetalonb16g** » Sun Jul 16, 2006 12:54 am

there is another in the yard that I will grab and see if it works , I will update if It does or not.

But other than that I'm open to any other suggestions.

gtuturbo · Post by **gtuturbo** » Tue Jul 18, 2006 3:25 am

(whitetalonb16g @ Jul. 15 2006,16:55)Q
U
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EWHAT is really annoying me is that I have no idea what my gas gauge is reading. Prior to installing the digital dash I filled up my gas tank to the max and it is still reading EMPTY.
That's because the fuel level sending units are different between the digital and analog dash.
You are going to have to put the correct unit in your tank or find a way to compensate for the resistive differences.

Is your coolant temp gauge accurate by chance?

whitetalonb16g · Post by **whitetalonb16g** » Wed Jul 19, 2006 7:19 am

Ok, I just put the new dash in yesterday and the fuel guage is reading full like it should. Also I must of overlooked the trim piece that has the switches that control the odometer, mpg, trip, tach, etc... on the right side because I also grabbed that and my right side of the cluster is working now. The FAQ never mentioned that you needed that trim piece around the dash and the donor car I pulled it from didn't have it. The second car I grabbed it from did.

So all is fixed and I will see in a day or two if the fuel gauge is accurate and moves.

Again thanks for the help guys. Hopefully my dilemma will help anyone down the road who has the same problem and they come across my post.

whitetalonb16g · Post by **whitetalonb16g** » Fri Jul 28, 2006 5:52 pm

(bereta1 @ Jul. 18 2006,02:25)Q
U
O
T
E(whitetalonb16g @ Jul. 15 2006,16:55)Q
U
O
T
EWHAT is really annoying me is that I have no idea what my gas gauge is reading. Prior to installing the digital dash I filled up my gas tank to the max and it is still reading EMPTY.
That's because the fuel level sending units are different between the digital and analog dash.
You are going to have to put the correct unit in your tank or find a way to compensate for the resistive differences.

Is your coolant temp gauge accurate by chance?
Well I think you might be correct on this one. Ever since my last post my gas gauge worked fine and it hit about 1/4 full untill I decided to fill it up. I put 12 gallons in the tank (really full) and left the gas station as normal and the freeking fuel gauge is not reading again now.

I will update in a day or two to see if the gauge starts reading again. I think what is happening is the sending unit is sending a certian "ohm" or "resistance" to the digital dash and the dash does not recognize it and it just goes blank untill it gets in the range on the analog resistance settings.

If it starts reading again, I guess I'm going back to the yard and grabbing the fuel sending unit and dropping my tank.

Bleh, and the FAQ said the digital dash swap was easy and never mentioned any of this.

If anyone else has done the swap let me know if this ever was a problem to you or not.

oh and beretta1 - my coolant gauge seems to be reading alright it is 1/4 way up and seems to reading correctly. The only thing I found out wierd about the dash after I put in the trim plate is on one of the buttons it has a TEMP setting. Is that setting for engine temp or is that for outside temp ? The reason I am asking it is reading -38 degrees or Fareheight (don't remeber, but i can switch it)so I'm thinking I'm missing something or something is working right.

Thanks in advance.

31beretta · Post by **31beretta** » Fri Jul 28, 2006 8:32 pm

I always thought and I believe I read that the temp button on the right side (with all the other buttons) is outside temp. Most times mine seems accurate, but other times it can be off like you said it read -38

gtuturbo · Post by **gtuturbo** » Sat Jul 29, 2006 12:42 am

(whitetalonb16g @ Jul. 28 2006,17:52)Q
U
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Eoh and beretta1 - my coolant gauge seems to be reading alright it is 1/4 way up and seems to reading correctly. The only thing I found out wierd about the dash after I put in the trim plate is on one of the buttons it has a TEMP setting. Is that setting for engine temp or is that for outside temp ? The reason I am asking it is reading -38 degrees or Fareheight (don't remeber, but i can switch it)so I'm thinking I'm missing something or something is working right.
You need to retrieve the outside air temperature sensor mounted in front of the radiator, that is if it still on the donor car.
If I remember right, it was 20-25 dollars at the dealer. They still have them.

whitetalonb16g · Post by **whitetalonb16g** » Sat Jul 29, 2006 4:47 pm

ok, im not too too worried about the air temp, I was just wondering.

As I was driving home today from work I noticed the gauge slowly going up towards Full. So now its reading normal again.

There is alot of the same issues on Bstuff.net about the digital dash and the fuel gauge that I found out last night. I might just deal with it for now, but I want to test to see if "E" is empty but I need to start carrying a full gas can in the trunk

1988GTU · Post by **1988GTU** » Sun Jul 30, 2006 12:46 am

I know if I over filled my GTU, the digi would read empty and blink at me. Once it got within "range" it started to read again.

Post by **Cliff8928** » Fri Aug 04, 2006 3:24 am

The coolant temp sensors are the same between digital and non-digital cars. The analog cars just get their temp reading on the dash from a different sensor in the cylinder head (which is no longer being used). The fuel level sender in the tank IS in fact different, but not in resistance, but in that there is a separate ground for the pump and sender, where they share it in an analog car. The Digital sender has a 4-wire weatherpak plug, the analong has only 3. You should be able to mount a resistor inline the fuel sending unit wire to correct for the gauge going out when it's full, I remember there being a TSB about that.

whitetalonb16g · Post by **whitetalonb16g** » Fri Aug 04, 2006 9:25 pm

(Cliff8928 @ Aug. 04 2006,02:24)Q
U
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EThe coolant temp sensors are the same between digital and non-digital cars. The analog cars just get their temp reading on the dash from a different sensor in the cylinder head (which is no longer being used). The fuel level sender in the tank IS in fact different, but not in resistance, but in that there is a separate ground for the pump and sender, where they share it in an analog car. The Digital sender has a 4-wire weatherpak plug, the analong has only 3. You should be able to mount a resistor inline the fuel sending unit wire to correct for the gauge going out when it's full, I remember there being a TSB about that.
hmmm the resistor idea sounds good, any idea on what size or more info on this TSB ? I will do some searching to see what I can dig up.

Thanks for the info

Scanman88GT · Post by **Scanman88GT** » Sat Aug 05, 2006 11:41 am

I used to have the actual service bulletin listed on a Popular Mechanics auto CD Repair cd-rom specifically for Beretta's, but can't access it anymore for some reason.

It had something to do with the fuel tank sending unit being a little too sensitive for the gauge circuitry in the digital dash. From what I remember, the fix involved using a 2000 ohm resistor (either half-watt or one watt size). That's not a commonly stocked value, but 2.2K or 2200 ohms is,and should still work fine. You can get them at Radio Shack.

From what I remember, you had to solder this resistor between the wire having the pink stripe in the harness running along the floor under the driver's side rear seat and a black ground wire. The bulletin suggested removing a small section of the wire's insulation and actually soldering the resistor lead to each wire, then covering up each end with electrical tape. I would suggest "tinning" the bare spots on each wire with a little solder before attempting to solder the resistor leads. If you lightly "tin" each end of the resistor leads before attempting this it will make a much better connection and should only take a couple of seconds to get a decent solder joint.

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