What's the procedure on this? Does this just mean the main ground strap etc. or every ground in the entire car? Are there certain grounds that tend to be troublesome? I am having some erratic gauge readings and other electrical gremlins and thought I would start with the grounds. Any advice?

<img border="0" alt="[byebye]" title="" src="graemlins/wave.gif" />

Thanks!

 

I cleaned the connections on the back of the temp/fuel guage and that seemed to help.

 

There are quite a few grounds to check and clean up but you have an '83. Bad news grounding off the battery after all these years. You want to pull the bare copper straps off, throw them away and replace with the new style ground cables.

In the new style, one insulated ground goes from battery to sheet metal by battery like your original. Another insulated ground follows the starter positive through the firewall and goes down to the bellhousing. Upgrading helps a lot and I have some new ones for $44 plus shipping.

I have also found that adding a supplemental ground from the front of the engine block to the forward frame rail where the lights ground helps quite a bit also. There is a ground bottleneck somewhere that I have never figured out but going to the frame rail seems to solve it. That cable is $20.

After this you have turned your sheet metal into a good grounding surface.

 

Get Iceshark's cable, it will make you wonder what kinda crack they were smoking when they designed the original grounds.

 

Dan, is this a good spot to ground to when going from front of the engine block to the forward frame rail?

Or am I way out to lunch on this?

<img src="http://members.rennlist.com/zehnd/Ground%20Picture.JPG" alt=" - " />

 

Donald, that looks fine as you have a good solid connection into the aluminum engine block.

The only thing I would gig you on is that you used a bare copper terminal rather than tinned copper. Bare copper will oxidize in the wet and heat of the front of the engine bay. So coat the terminal with some dielectric grease to stop the future corrosion. You can find the dielectric at the local auto parts or electronics store. It is usually silicone based and will take the engine heat easy without melting and dripping off.

 

Thanks for the info. I happen to already have a new ground strap to install. Since its a near direct replacement is it going to make a difference at all? If its not worth it maybe I can send it back and get IceShark's kit, let me know.
Also, is there any reason to check the grounds on each piece of equipment or is it going to be just a problem with the main grounds?

 

btw...while you are at it (after all, the car is over 20 years old)...you might want to take the positive battery terminal apart and clean the corrosion off ALL those wires...and the starter motor wires are probably a mess too...use dielectric grease ‘tune-up’ on them to help keep the connections from oxidizing again…lots of other connections/plugs can use some of this attention...many have reported better running engine and lots of flaky electrical problems cured afterwards

they make tools to help do this, such as:

<a href="http://www.performanceproducts.com/ProductPage.aspx?productname=Electrifix&productid=102177&producttype=10" target="_blank">http://www.performanceproducts.com/ProductPage.aspx?productname=Elec trifix&productid=102177&producttype=10</a>

 

Skitch, If you bought the original bare copper strap type grounds that came on your car return it and get your money back. You want the newer style that also has a direct run from the battery to engine block.

The grounds that need the attention are those that are exposed to the elements, i.e. engine bay. The grounds in the cabin are usually OK even after 20 years unless the car has been in very humid/salt water climate.

As Tom noted, at one point you need to address the positives. If you have surface corrosion then scrubbing with wire brushes and applying dielectric grease works fine.

But there can be two problems that usually require replacement of the positive cables. Since Porsche just used crimped bare copper terminals, corrosion can walk up the wire strands inside the terminal, increasing resistance and dropping voltage. You need to cut the terminals off and replace either the terminal or whole wire run.

The other really scary problem is the insulation cracking off due to age and heat cycling. Since the battery to starter and alternator runs are not fused, if you crack off the insulation and short you have a very good chance of starting on fire. Just ask Perry951. A good battery is going to dump over 600 amps into a hard short and you can arc weld with that amount of current. So, at some point you want to replace those cables because the insulation is NOT going to last forever.