Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Dec 2015
Location: Pound, VA
Posts: 994
Garage
LED instrument illumination pulsing.....

Got the tail lights sorted out with the resistors and they were great. I had converted my instrument illumination lights to cooler LED's (the incandescents simply are too hot and melt the damned bulb shrouds over time) and while doing yet another coolant bleed procedure in this damned 88S, it starts to get dark. So I turn on the lights. Damned LEDs in the instrument panel are pulsing. Noticeably. The hell? Anybody figure out how to shut these damned things up?

__________________
87 944N/A since 1992
87 944S - Near Future Engine Project Car
88 944S - Current Project
84 928S - Restoration Project
Old 06-12-2017, 05:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: May 2017
Posts: 181
Had the same problem once when trying to change over to the LED's for the first time. Aparently you have to buy the LED's with a built in resistor or else they will flicker, don't know if this is what your experiencing but hope this helps
Old 06-12-2017, 07:02 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Oct 2002
Location: Boulder, CO
Posts: 843
If you are melting stuff with the cluster lamps you may be using higher wattage than stock bulbs in there. There is no need for this, stock wattage is fine if the light directors are repainted. The gauges should not be super bright, that just makes it harder to see the road.

If you got LED replacements for these lamps like off ebay or whatever they may be sensitive to electrical noise. More likely, you may have a bad dimmer, it may have gotten a workout if you put in overwattage bulbs before.

The dimmers do not work properly with LEDs, ideally you put in a proper driver circuit. IMO it's better just to make the stock setup work properly. If you cannot dim the panel illumination that's bad news in bad weather.
__________________
1987 928S4
1992 968 cabrio
1994 968 cabrio - Supercharged
Old 06-13-2017, 03:57 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Dec 2015
Location: Pound, VA
Posts: 994
Garage
These actually will dim. I think I'm going to have to go with the LED's with a built in resistor.

The stock bulbs in the cluster were the original bulbs. After 30 years of heat from the bulbs, they will distort regardless. I've not pulled a cluster yet that didn't exhibit some signs of heat damage from the larger 3 illumination bulbs.

The rear tail lights are cooperating like a champ, just these instrument cluster lights are giving me a fit now.
__________________
87 944N/A since 1992
87 944S - Near Future Engine Project Car
88 944S - Current Project
84 928S - Restoration Project
Old 06-13-2017, 04:34 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Join Date: Oct 2002
Location: Boulder, CO
Posts: 843
I've had the cluster out in a half a dozen 944s and no heat damage found. The silvering comes off the light tunnels but otherwise I have not seen a problem. Some goober probably put w5w bulbs in from the auto parts store.
__________________
1987 928S4
1992 968 cabrio
1994 968 cabrio - Supercharged
Old 06-13-2017, 06:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Dec 2015
Location: Pound, VA
Posts: 994
Garage
On the last one I did, the silvering had degraded on the light tunnels. I tried to recoat them with a couple different methods. Both failed miserably. Finally, I stripped them again and polished them up with Blue Coral Metal Polish (works great on plastic) and left them alone. They reflect the light even better without anything on them.

__________________
87 944N/A since 1992
87 944S - Near Future Engine Project Car
88 944S - Current Project
84 928S - Restoration Project
Old 06-14-2017, 05:05 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 12:37 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.