Opelotus

I've been thinking about converting my cluster to solid wires and replacing all the bulbs with LEDs for some time now. I got this idea from a thread on the Pelican Parts Forum, credit goes out to whoever has already done this. I have started to collect some parts: wire, ring tongue crimp connectors, d-sub connectors, 5v regulators. I still need red LEDs and a couple misc. pieces.

I think this is a worthwhile project for several reasons;
-IIRC the flexible plastic conductor is NLA and can be a pain to repair. Solid wires eliminate the plastic conductor.
-converting to LEDs will provide better lighting + less current draw
-LEDs can be controlled powered by a 5v regulator = no dimming of lights while cranking and no change in brightness from key on engine off to engine running

I have a few questions though before I can get busy rewiring:
-can I use a 12v regulator for the gauges (except volt gauge) to try and stabilize/increase their accuracy? I have a few minor issues where the gauge readings will change when I turn the parking lights, or hazards on. Also if working at a fixed voltage, the gauges could be calibrated more accurately.
Please correct me if I am wrong.
-I bought three sets of 15 pin high density d-sub connectors at Radioshack (one to replace each of the 14 pin plastic connectors), but I am worried that the pins are too close to reliably solder. This is the only 15 pin connector that Radioshack sells, I do not want to use a 25 pin if I can help it.
http://www.radioshack.com/product/in...ductId=2102601

Finally, I touched up the wiring diagram for the cluster so it is readable, I still have to label it (MY '84).

If anyone has suggestions or additional modifications please post!

Opelotus

here is the wiring diagram so far:

WallyP

The MY84 wiring diagram is awful. I usually look at the MY83 and the MY85 diagrams in conjunction with the MY84 to help solve electrical problems.

Ducman82

i have always wanted to re do the dash wiring like that. have 3 custom connectors to the rest of the car, and a nice wire job.

tlsmith1999

For which years is the foil NLA? I had thought only the 78 foil was NLA.

soontobered84

Tim,
'84 foil is NLA

tlsmith1999

Note to self: Next 928 will not be an 84. I have had to replace the foil in my 79, and have a NOS 78 foil squirreled away in case that one gets any worst than it already is.

Opelotus

yes the '84 wiring diagram is a mess. I erased all the connections that are not present on my car (ABS light, belt tension light, etc) and added some color: it is much easier to read now. I think once I have all the parts and a good idea of how I want everything to work, it will be easiest to start with the devices that have common power, then everything that has common ground, then wire up the individual grounds for the warning lights and the signal wires for the gauges. Still not sure how I want to incorporate voltage regulators for the LEDs, I have one that is adjustable so I wouldn't have to use resistors for each individual LED, but the gauges get power from the same wires as the lights so I would need to split up the circuit (maybe put the regulator right on the back of the cluster?)

ROG100

928 641 923 00 - 78 Out of Stock
928 641 939 00 Late 78 to 81 available - $278.34 - 52 available
928 641 973 01 82 to 84 Out of stock
928 641 973 02 85 to 88 available - $118.76 - 35 available

jpNcos

Wow. No 82-84. I'm glad I have stashed a couple away.

Steve944

there was a post on here where someone soldered wires to the thin strips of copper and replaced the plugs on both dash circuit and harness and solved all his problems with the connection at the plugs, i have a 82 928s euro, and i do not think my printed curcuit will last thru another dash removal, so i was thinking of doing it his way, but if you get yours done up, you could probably start a reproduction on this because a lot of people are having problems with this

txhokie4life

Since I just picked up an '82 Euro --

is the 82-84 the same -- if so I'd love to have a kit for your
gauge project.

While I have no experience with doing such a project -- I think your
idea of locally regulating to 12V is a great idea.

Also -- are all the LEDs 5v? I live in the world of 1v (design computer chips)

I haven't seen more than 3.3v in 20 years and more than 1.8v in probably 15 :-)

How much is an instrument cluster -- I'd love to work on it in
outside of having to pull mine out - then just do a complete swap when
I get it wired up and get it right :-)

mike


Mike

soontobered84

Roger,
Does the '84 Euro use the '82-'84 circuit foil or does it use the '85? The Stepson's circuit foil is getting really bad.

tmpusfugit

As an ex electronics tech may I recommend using multi-colored wire in the rewire effort? The last effort on this was all done in black wire, an excellent effort but for the single wire color. As in the above drawing (nice work Opelotus) Red for positive, brown for negative, and other mixed colors for the various crcuits will make wiring and troubleshooting much easier.

IMO the circuit board connectors are the weakest link and the root of many panel problems. The standard connectors tend to not connect well under repeated use. 37 pin connectors are available, one of which could handle the entire cluster needs.....

Opelotus

The LEDs I plan on using will work on ~3.2 volts. There are several ways to go about incorporating them into the cluster along with voltage regulators. I could use a 12v regulator for all the power going into the cluster, but there wouldn't be much of an upside because to stay @ 12v the regulator needs something like 13.5V input. Anything below that and the regulator's output drops below 12v. Thats why I want to use 5v regulators, because their input voltage can drop to ~7v before the output voltage drops too. Therefore no dimming of LEDs when cranking, or with engine off/engine running. Of course the gauges would need to be @ 12v+ to function properly, I still have alot of testing to do to see if a constant 12v source will increase accuracy, if not they will not be used.

So I have several options:
5v reg for LEDs and 12v for gauges (preferred)
5v reg for LEDs and no reg for gauges
12v reg for LEDs and gauges (assures LEDs operating voltage never goes above 12v, but will not prevent dimming)

As of right now I have red, black, and green wire from Radioshack, but would like to find more colors so the above picture can be used for diagnosis/simplicity of wire and connection identification.

Another issue is finding suitable LEDs to use for the cluster lighting. I tried some 5mm 20K mcd white LEDs and they are not nearly bright enough to illuminate the cluster. Also their visibility angle is limited, unlike an incandescent bulb which is visible from all angles. I know this has been discussed on other threads and it may just be easier to go with pre-made plug in units from SuperbrightLEDs.

I had an idea to use tri-color LEDs for the cluster lights so the color can be changed at the push of a button, but I'm not sure they are bright enough. Also not sure if colors besides white will look any good.

The final version of the wiring diagram is almost finished, just need some additional labeling, will post when it is ready.