That was excellent advice!

You can't believe how much brighter my replacement Ebay cluster was after I took a Sanford eraser to the tabs when I got it cleaned up and changed all the bulbs.

A tiny amount of dielectric grease or even Vaseline may help prevent oxidation of the copper foil.

Wish I still had my old cracked cluster.
I would experiment with how much 12V current I could get to flow on the Mylar traces before they cooked or fused.

I'd think the ground trace would go first since all the indicator and illumination current flows through it.

 

I took my cluster out and did some cleaning. All bulbs were good. Removed the bulb-caps and now I can see! Caps popped out easily by just squeezing them. I may change to Red or Green bulbs but no hurry.

 

High resistance ... its a killer.

Think about it ... the electric COMPONETS in a vehicle were designed by engineers who anticipated the loads and mechanical stresses of doing a JOB ... and 98 almost 99% of the time these engineers do a REAL good job designing electrical parts for vehicles.

Where they fall down is CONNECTORS especially in vehicles from the 1970's to the 1990's. It was this time period that more and more automotive devices were becoming more ELECTRICAL then mechanical. Most of the components and parts were pretty good quality ... the CONNECTORS, however, stunk on ice.

Once you get high resistance in a circuit ... especially on the ground side ... you create HEAT ... heat that the system just wasn't designed to carry.

And then *poof* you burn out a Dura Spark module (or 3 or 4) ... and you blame the spark boxes. But what you really had was high resistance, green corroded connections building up HEAT in that box that it was never designed to handle.

Whenever I come across a failed electrical device ... a window motor, heater switch, heat light dimmer switch ... anything ... I ALWAYS check the connectors in the circuit AND ANY GROUNDS. In better then 75% of the stuff I've replaced ... I found that that there was a high resistance connection in the circuit, rather than a short to ground or a short to power that caused the failure.

 

agreed. connections always a toublespot. a big problem with the modules was the way they were mounted on the inner fender cover....no air circulation underneath. I remounted using 4 washers under and solved heat problem with air moving under the module. lotsa stories about melting epoxy is why I did that.

 

I wonder if anyone out there is using ultra bright LED's with the 194's T-10 wedge base?
These would draw less power and emit more light and less heat than any incandescent bulb while having a life of 10k+ hours.
They can be had in white, red, yellow/amber, green or blue.
http://cgi.ebay.com/ebaymotors/Wide-...item2ea2ee6ed7

These are the same guys that sell all the Ford parts manuals on CD recommended by NumberDummy (Bill).

 

Good to know this type of bulb is available. Thanks for the post.

 

LEDs are non dimmable if I remember correctly.

 

I was able to somewhat dim a few LEDs I had in my Autometer gauges, but they only dimmed a little. Nowhere near what the incandescent bulbs do.

 

HiPoParts just replied that these LED's draw about 1/10 of a watt

SOooooo, you could have FIFTY of these LED's for the draw of ONE #168 bulb.

 

I removed the old, brittle blue plastic covers and...voila now I've got great cluster lights. Thanks again to Franklin.