| Author |
Message |
magoo (Magoo)
| | Posted on Wednesday, October 10, 2001 - 11:24 pm: | |
You're right Bill, The origs. are not the best rheostats. That's why I thought it was a better idea to replace it with the proper ohm control. |
Bill Sebestyen (Bill308)
| | Posted on Wednesday, October 10, 2001 - 11:17 pm: | |
Magoo,
If you could find a lower resistance rheostat that could certainly work. Look for one with low resistance setting approaching 0-ohms. You might want to put a good ohmmeter on your existing rheostat and see what the resistance range looks like. Then you could compare it to a replacement rheostat and make a judgement as to how much it would help. The beauty of a resister in parallel is that it'll probably only cost a buck or two and you preserve your original rheostat, unless it's totally flakely. Bill |
magoo (Magoo)
| | Posted on Wednesday, October 10, 2001 - 10:39 pm: | |
Bill, since these rehostats on the older cars are a bit shaky and flicker off and on while you are driving, why not install the proper ohm rehostat, makes the lights brighter and adjustable. I will say one thing though, that bulb modification does "squat" hardly anything to improve illumination. |
Herbert Edward Gault (Irfgt)
| | Posted on Wednesday, October 10, 2001 - 3:33 pm: | |
Evidently this is the case with the Ferrari Resistor, it does not go to zero ohms for full power when turned all the way up. I see no problems with doing it this way as the bulbs are the same as used in a lot of other cars I service that are fully powered and there is plenty of air gap inside the individual gauges for heat dissipation. |
Craig Dewey (Craigfl)
| | Posted on Wednesday, October 10, 2001 - 6:47 am: | |
I've seen high power variable resistors like this not go to zero ohms because the wiper contact stops before the end or it doesn't make good mechanical contact where it's usually positioned(at the end). I've just put an electrical jumper across the last few wires, or made the wiper contact wider so that it makes zero ohms at the end of travel -- assuming you can get inside this one. |
Herbert Edward Gault (Irfgt)
| | Posted on Wednesday, October 10, 2001 - 6:24 am: | |
Jumping the rheostat is what made the biggest difference. I do not care if the rheostat does not work anymore since my object was to make them brighter with no need to ever want to make them dimmer. This modification makes them just right for my use. |
Bill Sebestyen (Bill308)
| | Posted on Tuesday, October 09, 2001 - 8:33 pm: | |
Herbert,
Did you get more benefit replacing the bulbs or jumping the rheostat?
Jumping the rheostat renders the rheostat non-operational. An alternative to a simple wire jumper between the input and output terminals of the rheostat, would be to solder a resister in place of the jumper wire. Sized correctly, you would retain the functionality of the rheostat, yet lower the overall circuit resistance and gain brighter lights. This method would also reduce current through the rheostat and does not preclude use of the brighter (lower resistance) bulbs.
As an example, suppose one measured the resistance of the rheostat and found its resistance varied between 5-20 ohms. Then suppose one wired a 5-ohm resister in parallel with the rheostat. For the minimum resistance case (5-ohms), total resistance is 1/(1/5+1/5)=2.5 ohms. If you run the numbers, or measure the resistance with an ohmmeter, you will find the combined rheostat/resister combination range will give you a total adjustable resistance of 2.5-4 ohms. The overall benefit depends on the overall resistance of the rest of the circuit. If the rest of the circuit resistance is say 50 ohms, the benefit will be small (2.5/(50+2.5)=0.048) or 4.8%. If however, the rest of the circuit resistance is less, say 10 ohms, then (2.5/(10+2.5)=0.20), you will have reduced the overall resistance by 20%. This means 20% more current passes through the light bulbs, which should be noticeably brighter. Similarly if one were to use a simple wire jumper (0-ohms), then if the total circuit resistance was 50 ohms, the reduction in resistance will be (5/(50+5)=0.09) or 9%, for the minimum resistance case, but no adjustability. The reduction in resistance for a 10-ohm circuit will be (5/(10+5)=0.33) or 33% for the minimum resistance case, but again, no adjustability. Bill |
magoo (Magoo)
| | Posted on Tuesday, October 09, 2001 - 6:29 pm: | |
Herbert is right the bulb change is a "little" brighter not much. Either jumping the dash light potentiometer or installing a different potentiometer is the best way to go. Or when you want to read your guages at night just use the flashlight under the seat. |
Herbert Edward Gault (Irfgt)
| | Posted on Tuesday, October 09, 2001 - 4:56 pm: | |
I put the brighter bulbs in mine and it was little help. Jumping the rheostat worked fine and I see no future problems. I have driven for hours at a time with no apparent problems. |
david schirmer (David)
| | Posted on Tuesday, October 09, 2001 - 11:37 am: | |
There is a faq on how to brighten dash lights on the NW region Ferrari Club site. http://www.ferrariclub.com/faq/dashlights.html
I asked the guy at Palo Alto Speedometer about brightening the lights in the speedo and tach and he recommended against it. I mentioned both the higher wattage bulb idea and the potentiometer idea. In both cases more light equals more heat and he said there could be problems with this. So that's what I've heard. YMMV.
BTW I think this thread started out as a question on how to remove the binnacle without removing the instrument panel so I don't quite know how we got here... |
Bob Campen (Bob308gts)
| | Posted on Tuesday, October 09, 2001 - 10:50 am: | |
I just installed the light upgrade from Italian Car Parts, and it is brighter at anything above idle. $26 for bulbs is a bit much. |
Charles Gault (Knox_Charles)
| | Posted on Tuesday, October 09, 2001 - 10:17 am: | |
Herb, Magoo,
Does the 328 insrument cluster detach the same way as the 308's? I would sure like to make my dash lights brighter. Also are the wires to the dimmer in the cluster or are they under the dash? |
magoo (Magoo)
| | Posted on Monday, October 08, 2001 - 10:45 pm: | |
Herb, makes a good point about brighter dash lights. Since they are brighter bypassing the potentiometer then one should be able to replace the existing potentiometer with another that will give brighter dash lights. |
Herbert Edward Gault (Irfgt)
| | Posted on Monday, October 08, 2001 - 9:14 pm: | |
If you want to make your bulbs brighter while you are in there, you can remove the two wires from the dimmer potentiometer and jump them together eliminating the dimmer and you will have beautiful bright dash lights. |
magoo (Magoo)
| | Posted on Monday, October 08, 2001 - 4:35 pm: | |
That is correct Greg. |
Greg Owens (Owens84qv)
| | Posted on Monday, October 08, 2001 - 3:45 pm: | |
If you want to change the light bulbs for the instrument cluster, I would assume that you also need to remove the four screws for the instrument cluster and pull the cluster forward? |
magoo (Magoo)
| | Posted on Monday, October 08, 2001 - 2:11 pm: | |
Stacy, Andy is correct. Take out the 4 colored lens in each corner of the instrument cluster and remove the screws recessed back in the holes. The cluster will come forward. Then disconnect the various wire harnesses. Remove the cluster and there will be 4 nuts securing the cluster cover to the dash. Remove those and the cover pulls off. |
Andrew Chapman (Xx7xx)
| | Posted on Monday, October 08, 2001 - 12:49 pm: | |
You do not need to remove the instrument pannel to remove the dash pod. I believe that there are 4 nuts that hold the pod to the dash. All four can be accessed from under the dash with a socket wrench with a 6" extension. I took of mine in about 5 minutes, however getting those nut back on was a little bit of a challenge.
Andy |
stacy o'blenes (Stacy)
| | Posted on Monday, October 08, 2001 - 11:16 am: | |
Does anyone know what is involved to remove the vinyl part of the instrument pod on a 308. The edge near the steering wheel is worn from contact with fingernails. The rest of the dash is like new so if it is not too tough I am considering removing that part and having it recovered. My guess is that if I remove the instrument panel I will be able to remove the pod from tha main part of the dash.
Thanks in advance for any tips.
Stacy |