993 C4S Electrical problem. Where to start?

[roybite]

I have a 97' 993 C4S with a new electrical problem. I have owned car for 4 years with no previous problems of any type. I noticed first that the stereo( radio or cd) would lose power when driving(usually when shifting)for a second and then regain power. Now when I shut the car off and lock it with my key fob and then try to unlock with the fob I hear a weak click at the door lock (the vacuum? lock does not unlock). When I unlock with the manual key and then try to turn engine on it is as if I have a very weak battery(dash lights weak) and engine won't turn over at all. After a random number of tries turning ignition on and off all of a sudden dash lights are normal brightness and car starts normally. I have replaced the battery and checked the battery terminals. I assume I must have a loose wire somewhere. Any ideas of where to start looking? I didn't know if this could be a fuse problem. Thanks in advance for any suggestions.

[cgfen]

Originally Posted by roybite

I have a 97' 993 C4S with a new electrical problem. I have owned car for 4 years with no previous problems of any type. I noticed first that the stereo( radio or cd) would lose power when driving(usually when shifting)for a second and then regain power. Now when I shut the car off and lock it with my key fob and then try to unlock with the fob I hear a weak click at the door lock (the vacuum? lock does not unlock). When I unlock with the manual key and then try to turn engine on it is as if I have a very weak battery(dash lights weak) and engine won't turn over at all. After a random number of tries turning ignition on and off all of a sudden dash lights are normal brightness and car starts normally. I have replaced the battery and checked the battery terminals. I assume I must have a loose wire somewhere. Any ideas of where to start looking? I didn't know if this could be a fuse problem. Thanks in advance for any suggestions.

1st choices = replace or clean the battery ground strap and the starter to chassis ground strap, (both ends of both straps).

good luck.

Craig

[techman1]

I second the ground strap. Even more, replace. May be connected good, but I have been told that even if it looks good, over time it will build up resistance. As soon as I changed mine my weird dash lights and other problems stopped. The strap I replaced looked almost new!

Neal

[Traveller]

Originally Posted by techman1

I second the ground strap. Even more, replace. May be connected good, but I have been told that even if it looks good, over time it will build up resistance.

A simple voltage drop measurement across the battery ground cable will tell you that.

All he has to do is turn on all high current devices (high beams, rear window defroster, cabin fan on high, etc) and measure the voltage drop across the battery ground cable. It should be in the millivolts at the most.