JohnCA58

When I bought this car, I had hot start issues when the weather was hot, even when cold, the starter had to much drag to start... so I replace the battery from a H7 battery to a H8 battery and replace the starter. the Y cable looked great, it started better when cold but when it was hot outside and your were making a short stop like fueling, I did not shut off the engine otherwise i would be waiting to start the car again when if finally cooled down. I finally got the car on the lift and decided i was going to replace the Y cable but did a voltage drop test on the ground cable first, it was ok at .01 drop. I removed the Y cable and save the junction box by heating it up with boiling water to be able to reuse it again, I did not want to replace it with Porsche OEM Y cable, I didn't care for the size cable used by the OEM, I went online to Battery Cable USA and ordered the 1/0 cable with 5/16 hole ends on each end and 30 inches long, I also ordered the 4 gauge cable with 5/16 hole ends for the alternator charging wire at 30 inches long, the total bill came out to 24 dollars and was at my house within 3 days across the country. I took the old Y cable and took the end that goes into the junction box and cut the cable off and installed a longer bolt 1 1/4 long and trimmed so I could close the cover again, I ran the alternator charge wire to the junction box instead of the starter, and installed the starter cable from junction box to the starter. amazing the difference in performance, now it starts like the spark plugs are not even installed, took it on 500 mile trip this weekend in up to 88 degree weather and no worries about shutting down the engine to fuel the car up, it turned over like it has no compression and of course it instant start up now. great company to deal with and the cable are flexible. i did cover them in wire loom to protect them.

Here is a link to the cable site
https://www.batterycablesusa.com/1-0...les-0-awg.html

Porschetech3

I did something very similar on my 99 Cab when my Y cable went bad. I have replace many Y cables when I worked at the dealership before I retired, and I'm no fan of the OEM Y design.

roadseeker

Apologies for reviving this older thread, but JohnCA58, I have a question about what you did. I'm about to replace my cable as well as have both the alternator and starter rebuilt as a precautionary measure as both are the original from a 2003. I have a few questions just for clarification.
1. You ordered both cables and ran both directly to the junction box? So there is no need for a cable to run from the alternator to the starter?
2. In regards to this quote "I took the old Y cable and took the end that goes into the junction box and cut the cable off and installed a longer bolt 1 1/4 long and trimmed so I could close the cover again", why did you need to cut the cable if you had already taken it off using the hot water method? Did you reuse a portion of the cable other than the box?
3. Since doing this almost 2 years ago, any degradation in starting power related to the cables?

Thanks so much for posting this alternative.

JohnCA58

1. No, no need to run a cable from the Alternator to the starter. Starter only needs battery power from the junction box and alternator supplies voltage back to the battery thru the junction box.
2. I only wanted to save the junction box (plastic) to reuse with new bolt and cables.
3. Still working great

Don't forget to get a 1 foot long 1/0 cable with 5/16 hole lug ends for your ground also.

roadseeker

JohnCA58,

Thank you very much for the clarification and the additional tip for the ground wire.

Emefef

When I first had the hot start problem, I of course thought it was the battery. The car was new to me, and I had a connection - so I had the battery replaced under warranty. It happened again 3 days later. Even though my Y cable looked great, a ran the extra wire to the (charge? boost?) terminal in the engine bay. It seemed to make a difference, but one day when the conditions were right (wrong?) it was really sluggish on a hot start. I found another post about the starter essentially having the same issues as a bad Y cable - increased resistance when hot. I replaced the starter and the difference cold and hot was amazing.

While I was recently replacing my broken oil fill tube, I removed the extra wire I previously added, because I'm certain with the noticeable difference in the starter, that it was the root of the problem. Of course - I'm not driving it enough right now to be able to test it. I removed that wired just to have it back to stock - but if I need it, I'll put it back in. I so look forward to removing the alternator again. It's funny, when I first did the wire, the alternator slid right out (full disclosure, it was recently replaced by the PO, to fix the hot-starting issue). That was in November. I was amazed at the number of YouTube videos on how to get the alternator out. I was like "seriously? take out the bolts, rotate it, tip it out. When I took it out last week, it took a hell of a lot of tapping and twisting....so I must have been really lucky the first time.