944Hybrids: 924/944/968 and 928 V8 Conversions
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HOW TO DO AN ADVANCED SEARCH.

Mon Jul 08, 2013 3:56 pm by Admin


For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

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A couple engine wiring harness questions

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A couple engine wiring harness questions Empty A couple engine wiring harness questions

Post  lsporsche Sun Sep 20, 2015 9:55 am

I'm currently working on my wiring harness and have a few questions. I'm following lt1swap.com instructions, but I'm thinking I jumped into this too quick and may have removed wiring I shouldn't have.

1. I kept 2 wires coming out of the pcm for fan relays 1 and 2. Are these necessary? I was under the impression the fans were in a separate harness from the engine and would remain intact during this swap.

2. Following lt1swap instructions, I removed the three connectors near the C2 connector. I believe now that these were my wires for my gauges? I'm debating making my engine harness completely standalone and then running the 2.5 water temp, voltage, and oil pressure sensors on the 5.3 as well so they read accurately and run straight to the firewall plugin. Would this work? The instructions did have me keep a white "engine speed signal" wire, which I believe will be for my tach.

3. After following the website instructions, I'm left with several extra plugs in the harness. I believe the VSS will hook up with the VSS that TPC sells, however I have two range sensor plugs that each have one wire left. Are these necessary? I don't know if maybe this pcm has a neutral safety switch or something that I need to bypass.

Sorry if these are dumb questions. I've looked around for that 948 conversion manual and found nothing. Even emailed the guy that used to sell them with no reply. Some sort of basic install manual would be nice.

Thank you in advance for any help

lsporsche

Posts : 72
Join date : 2015-08-26

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Post  Rich L. Sun Sep 20, 2015 11:04 am

On your #1, both are options. Some guys rewire the fan trigger to the LS PCM. But I left the 944 thermostat, relays and wiring as original.

I can't really help with #s 2 and 3 as I bought a stand-alone harness from Painless Wiring. It was pretty straight-forward to hook into the car at the fuse box and behind the glove box. Gauge senders hooked into the connector on the firewall driver's side. All these connections are documented here in the "Wiki" link top left of the page.

Good luck,
Rich
Rich L.
Rich L.

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Post  lsporsche Sun Sep 20, 2015 11:35 am

Thank you! I saw several references to a "wiki" section but didn't know where that was. Lots of good information there.

lsporsche

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Post  Arthropraxis Sun Sep 20, 2015 9:26 pm

I did my own harness. I got an alldata subscription for the model of car that the engine came from, used the site you are and info from Xschop on how to make a fuseblock. He made a diagram, if you search for fuse block it can be found. Use the electrical diagrams for the wiring and remove all the wires that don't go to anything anymore and you will have a stand alone wiring harness. I used my fan wires to hook into the Porsche system so the GM ECU triggers the fans. It should not be hard to hook them back into your ECU.
Arthropraxis
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Post  lsporsche Mon Sep 21, 2015 7:33 am

Thanks man. I think I have the harness right at this point, I'm waiting on parts to build the fuse block, obd2 port, and cel. The only thing I'm not sure about is a neutral safety switch. From what I've read it can be programmed out of the ls pcm, but does that mean I wont be able to start it until I've had the pcm reprogrammed? Surely there are 2 wires that can be jumped to bypass it.. I'll do some more researching. I have two wires left over from the range sensors (one on each plug) that I need to figure out if I need or not as well.

lsporsche

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Post  Arthropraxis Mon Sep 21, 2015 8:12 pm

I know I could not start mine for more that 3 seconds until it was programmed, some kind of security feature had to be programmed out.
Arthropraxis
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Post  sharkey Tue Sep 22, 2015 1:37 am

it depends on how you wire the starter. if you have the key hooked to the starter it will crank, if the key is triggering the pcm and the pcm is hooked to the starter solenoid, then it likely wont crank. as for the security stuff, unless you have the pcm reflashed it wont run for more than 2 or 3 seconds. vats needs to be turned off as the pcm doesnt have everything else it needs for the vats to function (gm ignition switch with encoded key, bcm, etc).

sharkey

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Post  lsporsche Tue Sep 22, 2015 7:36 am

Thanks for the replies guys. I'm going to have the key wired to the starter, not run through the pcm. I may send my computer off to lt1swap to have it reprogrammed beforehand though, so it'll actually run. Then I'll take it to get dyno tuned after it's all together.

lsporsche

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