Regarding my 1982 928s....I recently pulled the pod and gauge cluster to get to and replace my ignition switch. While it was out I cleaned as many contacts as I saw, replaced all of the backlight bulbs and cleaned up the pod itself.I put it all back in the car yesterday and now my tach and water temp gauges are not working. Before I pull it all back out,is there something obvious I may have missed? Do these gauges run off the same multi pin connection and I just didnt seat it properly? If so,which connector is it?

and a side question... it appears that the only lights working on the dash are the 3 front facing bulbs and the parking light warning. Arent the gauges supposed to be backlit,the dials and the numbers? I replaced all 20 of the back bulbs and I assumed they backlit the gauges. on the positive side,the ignition switch works as it should and I also have high beams which I didnt beforehand.
Chuck

 

Most of those bulbs in the back are for warning lights. Also turn signals, high beam indicators, etc. The "backlight" isn't really that...there are three or four bulbs along the base of the gauges that illuminate the gauge faces from the front, via some sort of prism or reflective thing, I don't know what to call it.

They will also be dimmed by the dimmer wheel under the pod, so make sure that isn't the problem...

 

this link will likely help you de-bug things... Good luck!

https://rennlist.com/forums/928-foru...lor-wires.html

 

Jeff,thanks for the light info. I was thinking that there would be more light coming from behind. My 3 front bulbs are working,along with the dimmer, I was just expecting a little more.

 

Monkez...great link! thats what I was looking for.Thanks!

 

Those incandescent bulbs are really dim compared to modern LED dashes. Also, the gauge illumination bits that I don't know what to call have reflective surfaces that apparently wear off or become less reflective perhaps...reducing the effectiveness of those bulbs over time.

I replaced all the bulbs in there with LEDs and I've been very happy with the improvement, not that you likely want to go back in there and replace them all again...

 

FWIW the original bulbs are quite brite for night time,
whats missing is the currrent to make them that way.

You know the drill Deoxit 100 the light connections and the potentiometer or fit a new part.

NOTE Putting in LEDS and then driving car at night will give some of the brightest lighting conditions you could ask for.

NOTE whats really needed is subdued lighting so your night time vision will be at its max,

NOTE bright LEDs will not permit max night time vision

 

Well, the gauge lighting via LED I find is much better, and doesn't impact my night vision at all. The warning lights can be bright, but hopefully you're not all lit up with them :-) The one that I do think is a bit too bright, in my car, is the green turn signal indicator. For whatever reason, that one IS too bright, and if I'm every back in there I might consider trying to find something a little bit dimmer.

That being said, I've never seen the gauges lit up in a "new" 928. I've done the deoxit and cleaning and all, but those incandescent bulbs were also 30+ years old, so it's possible they're not exactly at peak performance either.

The 924 I just picked up is far worse than my 928 ever was for dim gauge lighting, fwiw...

 

make sure you did not swap the connectors on the back. it will cause the gauges to not work correctly. (happens more than you would think)

 

My dash lights were awfully dim when my alternator was going bad. Newly rebuilt alternator made them a little *too* bright. The shift indicator is actually a little annoying now, and even passengers notice it.

 

The gauge clusters are quite fussy. Putting in new bulbs with new bulb holders doesn't mean that they'll come on. The foil circuit was pretty cool in 1978 but they don't age well. The connections to the harnesses can be tricky, too.

Check out the wiring diagram and see which connector has those gauge signals on it. You may get lucky by wiggling it from below.

I expect it'll need to come out. I always give the pod a trial check by connecting the cluster up without mounting it to the pod. It's just sitting on the steering column. Turning on the car lights all the warnings. Then idle it a bit to see if the gauges work.

 

Looks like I,ll be taking it back out to see whats going on. Once you do it,it really isnt that bad,you just need a little patience. I should have checked the gauges beforehand,this time I will. As far as the LEDs....... are there direct replacements for the 3 bulbs that illuminate the front? My warning lites are looking bright enough,as are the clock and heating/cooling lites. Maybe I,m getting old,but I think I would like the front lit a little better!

as a side note..this car is a pain in the ***...1 step forward..2 steps back....

 

There were direct replacements available for my '86.5. Different years had different lamp base sizes, etc so I'm not sure how your car might differ, but there are a couple really good threads on this topic, all the info I needed was buried in them.

 

Trust me, at night time LED dash lights are really too bright,
and they are not dimmable.

Listen to me now hear me later

 

You can get Ed's dimmer box to dim the gauge and switch lights, if you really feel that they are that bright. I don't, and I have them turned all the way up, so ¯\_(ツ)_/¯