Davies

After conducting the requisite search, I found a handful of posts pertaining to my problem, but much to my frustration, none reached any type of satisfactory conclusion...
As the title suggests, my radio is intermittently cutting out while driving (but immediately comes back on again). If I'm driving at night, when the headlights are on, I'll see them momentarily flicker when the radio goes out. Also, when the car is idling, there is the faintest hint of fluctuating/pulsating in the headlights...I've also noticed that my alternator bearing is starting to squeak. Assuming I must replace the bearing, would this affect the voltage produced by the alternator (with the canary in the voltage coalmine being the radio)? I'm thinking it probably would.

If that doesn't do it, I'm thinking it could also be:
- battery (mine's 3 1/2 years old)
- bad ground
- the alternator itself (replaced two years ago, so unlikely?)
- voltage regulator?
- radio wire connection issue (Also unlikely, I think)
- Alternator belt tension (it appears to be sufficiently tight, but can a belt harden over two years and slip, even when tightened?)

If there's anything I missed, please chime in...I was also curious what others who have experienced this symptom ultimately found to be the culprit. (Strangely, I have a friend who also has a '96 993 which is having the exact same problem...)

viperbob

Bad Battery most likely. Had the same thing happen to my car when I first bought it.

Davies

That's music to my ears Bob...Thanks!!

993C4Smontreal

I've had this problem. I press some button my mistake, and I lose all my preset stations. Any advise?

cesar

Our cars have radios?

Hardly every turn mine on. The real music is behind my ears.

Davies

I fixed the problem. It was the ground strap to the battery. When I wiggled the old one, the trunk light went off and on! It was tight, so apparently there was enough corrosion to affect the grounding process - Though to be honest, the lead looked fine except the copper brading had separated a little where it was bent. Anyway, for the sake of the archives, it worked!

RallyJon

Hmm, don't know how I missed this. Had a similar problem: https://rennlist.com/forums/993-forum/320773-sudden-brief-loss-of-electrical-power.html

My ground strap looks fine, but it's a cheap replacement, so what the heck...

Davies

Like ships in the night...I don't know how I missed your thread either, rallyjon!
Mine didn't look bad either...But it was definitely faulty. I replaced the negative battery strap this past weekend ($18), have driven every day, and the problem is gone.
Most time consuming part is wrestling with the damn collapsible spare...

INTMD8

Bringing this back from the dead to say I had the same issue and resolution. (radio cutting out intermittently).

I didn't replace the ground strap, just soldered the ends where the cable entered the lug. So far so good.

orangecurry

Change the strap anyway.

92% of all electrical faults are due to bad earthing. The resistance increases in any earth strap over the years, so the slightest hint of any electrical issue is the cue to fit a new strap with very clean connection points.

kjr914

I'm with orange curry on this... Soldering it probably created a surface fix. Did you saturate the joint in liquid flux and heat it with an oversized soldering gun (an iron probably won't generate enough heat for the size wire we are talking), then load it up with solder to saturate it into the cable core? On top of that, once soldered, the cable isn't flexible like the cable is supposed to be, so it will eventually crack.

OH, AND...
Its an $18.25 part from pelican....

INTMD8

The entire length of the copper strand cable was not saturated in solder so other than about a millimeter out of the lug it is flexible. Might crack in a few hundred years especially considering there is nearly zero relative movement between the battery and body.

And no, I used a torch and flux. I am unaware of a soldering gun capable of this.

This was done so I could find out in 5 minutes if this would help the issue, not because I'm trying to save $18.25.

kjr914

Ah, good call! The torch is an awesome idea!

Opps, didn't mean to suggest you were being cheap. It was merely I was shocked finding a sub-$20 Porsche 993 part (that isn't just a plastic nut).

pp000830

Consider topping off the fluid
In the battery with distilled water first and disconnect clean and reconnect the battery terminals, may save you the $100 battery cost.

Alfa40

For anyone with the similar problem, I just want to confirm that the ground strap was the culprit for me, too. I had cleaned the contacts obsessively which didn't help at all. Eventually, after replacing the DME relay and double checking that the wiring harness recall was performed, I decided to replace the strap for good measure and have not experienced the issue since.