911 Dash Electrical Fire Prevention - Cheap Insurance

[RickS]

More great tech articles to be found on Dieter's site - but this is quick and easy and may save your car...

http://www.dietersmotorsports.com/tech/1998/12-98a.html

[fourteenten]

Great article Rick!

It happened indeed in my car, a live wire got damaged by the speedometer cable and fried the headlight switch plus some wires of the connector. Luckily I saw it happening and turned of the main switch quickly.

Cees

[hdavis]

Seems like a great piece of advise, and looks like something even I could do myself.

Thanks

[RickS]

Even though I posted this advice, I did not heed it on the 914. After replacing a couple of bulbs in the speedo, I breifly turned on the lights to test, before situating back in the dash and I heard fssssssssssssst and then smoke.

I am now installing 3 amp fuses in my cars and then track down the fried wires

[68911+1]

Once was enough for me.

[RickS]

Just finished installing 'the insurance' tonight. Total cost $3.75. Total time, 15 mins. The picture you posted made it so simple. Thanks!

[TrackRat]

I had a short in the headlamp switch of my '73 last fall, but fortunately saw the "mushroom cloud" and smelled the burning and quickly shut the lights off before incinerating the harness... or the entire car. I'll be doing the fuse upgrade to the replacement switch during this winter's "down time" . Thanks for posting the "cure" and the detailed pictures of the fix.

[RickS]

Updated: Thought I would have to take the 914 to an electrical shop, but luckily the wiring for this style of car is relatively straightforward.

I was able to isolate the fried wire (after the requisite amount of time for removing all the stuff in the way and unwrapping the black sticky old cloth tape around the harness) and determine the others in the vicinity looked fine. Side note: It's always interesting working in unchartered territory, the stuff you learn, and some stuff you rather you hadn't, like a previous owner's highly unothodox attempt at wiring. Anyway, a fused bypass wire was installed- much heavier gauge - with 3 amp fuse. Then I tested everything and low and behold the fogs would not light. I just about flipped. Then I thought that perhaps the wire I perfomed my by-pass must have split to a relay, but I certianly saw no evidence of such (hrumph!). Back to the wiring diagram and did not find a relay but found that the light switch has two identical wires on opposite sides of the switch, and that I had merely used the wrong side (Whew!). Buttoned everything back up again and after a mere 2 beers, 4 hours(a trained monkey would have been able to probably do it in 2, with 4 beers) everything was operational and I was at peace with the world with the $250+ still secure in my billfold.

I slept well that night.

[Joe Minor]

I wanted to give this thread a "Bump."

I completed the simple project yesterday, but only after nearly $1000 labor to my mechanic to repair an electrical dash fire from this past summer. We're still not sure the exact cause of that fire, but from what I've read the dash lights are usually the culprit.

Thanks to the guys who originally posted this thread and the picture.

Hopefully someone will read this and apply the fix before they have a fire and not after the fact like most seem to.

[RickS]

I think I once met the guy who placed the original post, but am not quite sure. One thing I can remember is that I really didn't care for him much.

Joe, sorry to hear about the mishap. Its frightening how such a seemingly trivial short can cause such grief. Glad you got it sorted out.

I am not into self-promotion, but am into helping spare others from "the senseless tragedy and unnecessary spread of dash fires". It might be worthwhile to tuck this thread with the Best of Technical Info, or perhaps the "Second-best of" thread. Just a thought.