almost running need help
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almost running need help rebuilt motor installed somehow the alternator batt wire got mixed up and bolted to grounds on frame by abs installed batt cable sparks so i took it off . My main problem is now thats (fixed all grounds have been checked relays all in working order ) i get no fuel pump prime at fuel relay get my constant 12v then key in run get 12v but no 2-3 sec 12v for prime other issue starter will not turn over im getting no voltage to purple wire have 12v out of big red wire at batt couldim leaning towards a fried pcm due to the 12v alt wire to ground but not sure as i know vats is working ohmed key and checked plug under column both match just need help im new to ls game car iss 99 z/28 also speedo is pegged out all interior dash lights work horn blinkers
I suggest you search for schematics and figure out which wire coming right out of the PCM plug is responsible for triggering the fuel pump. Check for 12v right as it comes out and you eliminate all the relays and such. No voltage, could be a PCM issue. Lots of body control modules seem to be going out in F-bodies at this age and you might have helped that along so you might want to check that too.
Do you have all of your grounds hooked up properly post-swap?
Do you have all of your grounds hooked up properly post-swap?
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Yes all grounds are clean and hooked up i checked my fuel pump wire from pcm no voltage to prime i do have constant 12v on 30 lug of relay the no start im completly lost on im getting no voltage from purple wire
If you've got nothing coming out of the PCM then you probably need to try a different PCM. Have you verified that the PCM has power to it? VATS works with the BCM(different than PCM) BTW..might want to pull that and see if it is compromised as well.
With key on can you read/interact with the PCM via the OBD port?
With key on can you read/interact with the PCM via the OBD port?
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I grounded the black/yellow bcm wire still doing same i ohmed out the vats plug with key in ignition sane reading with key out so vats should be working ill try the scanner to see if it will comm and to verify the pcm has power would it be the 2 orange wires going in the pcm connector red an blue
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Ok i pulled both red and blue plugs off pcm i got 12v on both orange all the grounds in plug check out the blue conector pin 2 says 12 volt refrence i get 0 there with key on or off and 0 on fuel pump prime with both connectors off and batt hooked up of course
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I would briefly apply 12V to the fuel pump lead while the connectors are off the PCM. If the fuel pump fires up then you may have a PCM problem. Have you hooked up a scanner or similar to the OBD port yet?
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I hooked a obd scanner last night it communicated i tryed jumping fuel pump at conector under trunk it didnt come on im pretyy sure pump is dead but im still not getting prime signal at fuel relay and it wont crank over still starter has been tested and so has batt
Did you have 12V at the pump wires when you tried to jump it?
BCM will disable the starter. Again, I suggest you check this out. They fry on their own and with the issue you had, it seems like a place to look.
BCM will disable the starter. Again, I suggest you check this out. They fry on their own and with the issue you had, it seems like a place to look.
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Ok ill pull bcm today when i get home any good way to test it or look for bad solder on board and im pretty sure i had 12v i pulled the fuel pump relay had 12v on 30term of relay then jumped it to one of the other prong slots with no luck but i did have 12v constant on 30
I am not sure exactly but basic electrical troubleshooting usually gets you there. Easiest is to swap it with a known good unit. Here is some relevant reading to get you started:
http://camaroforums.com/forum/93-02-...-repair-52062/
https://ls1tech.com/forums/pcm-diagn...r-bcm-fix.html
Here is how to basically hotwire the thing:
http://www.camarozone.com/forum/f16/...-start-120118/
Some beginning reading on bypassing VATS altogether:
http://www.thirdgen.org/vats
Good luck.
http://camaroforums.com/forum/93-02-...-repair-52062/
https://ls1tech.com/forums/pcm-diagn...r-bcm-fix.html
Here is how to basically hotwire the thing:
http://www.camarozone.com/forum/f16/...-start-120118/
Some beginning reading on bypassing VATS altogether:
http://www.thirdgen.org/vats
Good luck.