wierd electrical help
Thread Starter
Pro
Joined: Oct 2006
Posts: 585
Likes: 57
From: Toronto
wierd electrical help
I have competed a motor swap and when i hook up the battery wierd stuff happens.
1 the radiator fan runs
2 the check engine light and foot well lights go on (no key)
3 starter turns ok when i turn it over
4 there is a small spark that comes of the ground straps when i touch them lightly to the block
5 with key on dic says reduced power,and fan turns off
i need help to diagnose please.
1 the radiator fan runs
2 the check engine light and foot well lights go on (no key)
3 starter turns ok when i turn it over
4 there is a small spark that comes of the ground straps when i touch them lightly to the block
5 with key on dic says reduced power,and fan turns off
i need help to diagnose please.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 301
From: Columbia SC
I will respond to #4. If the block is properly grounded back to the battery negative side(which seems like it is), and you have voltage in the ground strap circuit and touch it to the block you should see a spark since you are making the circuit complete. You should see the same thing if you touch the ground strap to the metal frame (assuming it is properly grounded back to the battery).
I'll have to ponder on your other issues for a while. Sounds like #3 is for info and not a problem. If so it would also indicate the block is properly grounded (I assume the starter is grounded via the block but am not positive (don't have a wiring diagram with me at this time).
I'll have to ponder on your other issues for a while. Sounds like #3 is for info and not a problem. If so it would also indicate the block is properly grounded (I assume the starter is grounded via the block but am not positive (don't have a wiring diagram with me at this time).
Thread Starter
Pro
Joined: Oct 2006
Posts: 585
Likes: 57
From: Toronto
yes number 3 is for information purposes, so a spark from the ground strap on the rear of the drivers head is normal then. I checked everything the starter wires are ok the grounds are all on the battery is brand new(car sitting for 2 years inside) I understand bill curlee seems to think these cars have ground problems i am going to set about cleaning some of them thanks for the response need another brain here to help with diagnose proceedure. I have a multitester can i install it between the disconnected battery positive and the frame then if there is a voltage registering look for a short by pulling fuses one at a time to see what the offending curcuit is? or does anyone think it could all be caused by bad ground i do see a bit of green on the ground connector on the frame near the steering box.
Tech Contributor
Joined: Jan 2007
Posts: 19,246
Likes: 1,095
From: Dyer, IN
I have competed a motor swap and when i hook up the battery wierd stuff happens.
1 the radiator fan runs
2 the check engine light and foot well lights go on (no key)
3 starter turns ok when i turn it over
4 there is a small spark that comes of the ground straps when i touch them lightly to the block
5 with key on dic says reduced power,and fan turns off
i need help to diagnose please.
1 the radiator fan runs
2 the check engine light and foot well lights go on (no key)
3 starter turns ok when i turn it over
4 there is a small spark that comes of the ground straps when i touch them lightly to the block
5 with key on dic says reduced power,and fan turns off
i need help to diagnose please.
Instructor
Joined: Dec 2007
Posts: 217
Likes: 52
From: RI
....If the block is properly grounded back to the battery negative side(which seems like it is), and you have voltage in the ground strap circuit and touch it to the block you should see a spark since you are making the circuit complete. You should see the same thing if you touch the ground strap to the metal frame (assuming it is properly grounded back to the battery).....
Are we talking about the same thing?
All grounds should be at the same potential.
There should be no current flow between grounds. Any current/potential between grounds would be grounds for a ground loop. <vbg, I just thought that up. Am I too funny, or what?>
dan k.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
Instructor
Joined: Dec 2007
Posts: 217
Likes: 52
From: RI
Lucky,
Once again, just to clarify, we are talking about a current flow between grounds?
If we are, it shouldn't matter whether a device is 'hot' or not. All grounds in a car should be at the same potential with respect to each other. Is this not correct?
I am not an electrical engineer specializing in autos with non-metallic bodies, so I'm prepared to be 'schooled' here, but how can you not experience ground loops with grounds at differing potentials?
dan k.
Once again, just to clarify, we are talking about a current flow between grounds?
If we are, it shouldn't matter whether a device is 'hot' or not. All grounds in a car should be at the same potential with respect to each other. Is this not correct?
I am not an electrical engineer specializing in autos with non-metallic bodies, so I'm prepared to be 'schooled' here, but how can you not experience ground loops with grounds at differing potentials?
dan k.
Tech Contributor
Joined: Jan 2007
Posts: 19,246
Likes: 1,095
From: Dyer, IN
Lucky,
Once again, just to clarify, we are talking about a current flow between grounds?
If we are, it shouldn't matter whether a device is 'hot' or not. All grounds in a car should be at the same potential with respect to each other. Is this not correct?
I am not an electrical engineer specializing in autos with non-metallic bodies, so I'm prepared to be 'schooled' here, but how can you not experience ground loops with grounds at differing potentials?
dan k.
Once again, just to clarify, we are talking about a current flow between grounds?
If we are, it shouldn't matter whether a device is 'hot' or not. All grounds in a car should be at the same potential with respect to each other. Is this not correct?
I am not an electrical engineer specializing in autos with non-metallic bodies, so I'm prepared to be 'schooled' here, but how can you not experience ground loops with grounds at differing potentials?
dan k.
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Racer
Joined: Feb 2003
Posts: 418
Likes: 28
From: Evansville IN
You wouldn't happen to have the ground that goes on the passenger side of the block, ABOVE the starter, on the starter lug would you?
There's a picture of the starter wiring in one of Curlee's threads I believe.
HTH
There's a picture of the starter wiring in one of Curlee's threads I believe.
HTH
Last edited by SMaster; Aug 7, 2012 at 05:23 PM.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
Thread Starter
Pro
Joined: Oct 2006
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From: Toronto
dimmer switch? i think you may be right it might be on i will check as for wires above the starter i only have the one heavy black ground off the battery going to the block is there another one on that side i missed the turbo hosing and such makes it very tight in there to see anything
Thread Starter
Pro
Joined: Oct 2006
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From: Toronto
by the way none of this explains the fan running issue and as for dtc only reduced power low fuel low tire pressure but the last two are right on i have low fuel and low tire pressure car has been sitting for two years
s master i have 3 wires on the positive terminal of the starter splenoid. large red from battery,heavy rust colored,small black with white tracer and i am wondering what a black wire is doing on the hot side? the picture you elude to doesnt make it clear
s master i have 3 wires on the positive terminal of the starter splenoid. large red from battery,heavy rust colored,small black with white tracer and i am wondering what a black wire is doing on the hot side? the picture you elude to doesnt make it clear
Thread Starter
Pro
Joined: Oct 2006
Posts: 585
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From: Toronto
s master you got me looking for schematics of g106 and now i thinks i got the problem you eluded too. correct me if i am wrong but the black wire with white tracer goes to block and not the starter solenoid yes? I am such an *******
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
I'm out...
Thread Starter
Pro
Joined: Oct 2006
Posts: 585
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From: Toronto
great picture and a fine thing too because i had the thin black on the solenoid put it on the block and viola the problems went away, so after my heart stopped racing because I was nervous as heck from all the work and wondering did i forget something else, I started the car after 2 years of work in fact today is the anniversary and she fired right up no problems. Now i can enjoy the fruits of my labours and try for 1000 rwhp after the break in period, to all who chimed in tryin to help me your always welcome when passing by to stay at my house raid my fridge drink all my beer and sleep with my wife
Cheers
Cheers
Le Mans Master
Joined: Mar 2011
Posts: 6,835
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From: Columbia SC
PhotonHunter: What I was trying to explain is if a circuit is powered, but the ground connection is not made you have no current flow. If you then touch the ground connection to the block (or anything else connected back to the battery negative then you should see a spark meaning you have now made a complete circuit. Just like you will see if you remove the negative battery connection and then reconnect it on the corvette since there are circuits that are "live" at all times.