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Old 02-18-2013, 11:57 PM   #1
themb2g
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LSX questions

I have a 1972 Blazer and a 6.0 lq4. We are putting the wiring harness together and i have a cuople of questions.

1. Can we eliminate the oil pressure wire to the PCM and use the old hard line straight to the gauge cluster, or will it mess up the computer somehow? Same question for water temp.

2. We have a one wire alternator from a vintage air front runner system. Do we need to run the alternator to the PCM or can we just bypass the PCM and run direct to the gauge?

3. Has anyone else used the Vintage Air Front runner on here for an Lq4? The alternator looks like it has a plug port, but there is a cap that wont come off.

Thanks!

MB
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Old 02-19-2013, 01:26 AM   #2
71chevystep4x4
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Re: LSX questions

As far as the oil pressure goes, you can just remove the pins and wires from the PCM plug and run the hardline to the cluster. Keep the temp hooked up because the pcm needs to know the temps the engine is running. Not sure about the alternator, I was wandering that myself. So far, mines not hooked up to the pcm, and everything seems to be working fine.
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Old 02-19-2013, 03:51 AM   #3
ls1nova71
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Re: LSX questions

As stated, you don't need the oil pressure sender. I usually break the plastic part of it off and drill and tap the aluminum base to accept the fitting for the line.

On the alternator, if it's.a 1 wire alternator then it's self exciting and nothing needs to be hooked up. That plug is where the wires would plug into a regular alternator but there isn't anything to hook up on a one wire so they put that plug in them.
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Old 02-20-2013, 02:16 AM   #4
BR3W CITY
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Re: LSX questions

Just to add, all the oil pressure wire does is tell the pcm that there is oil pressure...thats really it...and the pcm doesn't care what the answer is. I think its just used to trigger the idiot light if there is a complete loss of oil pressure. Some late model cars and trucks can get an oil pressure reading through the pcm, but these trucks do not.
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