Inconsistent Electrical Issues - Diagnosis

tonycondon

tonycondon

Gastons CRO (Chief Dinner Reservation Officer)
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Tony
Background- Matt Sawhill and I met at Matt Michaels heated garage this morning and spent the day putting new intake manifold gaskets on my car's engine. that went quite well and everything on the engine side of things is working well. amazingly we got the whole thing put back together, and it runs, with no empty holes or spare nuts/bolts!

Problem - On the 3 hour drive home tonight I encountered a few electrical issues that seemed to repeat but were not repeatable.

1) switching from low beam to high beam, occasionally the radio would skip or buzz a bass tone for a half second or so. One time I managed to kill the radio and panel lighting, and get the airbag light to flash, just by switching from low to high beam. switching back to low beam, then high beam returned everything to normal. engine ran perfectly throughout the episode.

2) when using the brake to slow from cruise control, headlights would slightly dim (may be normal, can't remember)

3) after arriving home, turned key off and all electrical shut down. usually headlights stay on and interior light is on when door is open. car would not start, as if the battery was dead. 1.5 hours later i went out and everything worked fine, car started. piece of cake.

any ideas?

Im sure we bumped a wire loose or something during the major dissasembly and reassembly required to get the intakes removed. now just to figure out which wire. I will be pulling the car into my parents heated garage tomorrow to take a look at it, appreciate any insights.
 
tonycondon said:
Im sure we bumped a wire loose or something during the major dissasembly and reassembly
Click to expand...
Probably right. Just take off the intake manifold and re-install, being more careful this time!:rofl::rofl:

These intermittent problems are a bear to find. Start by checking the security of all electrical connections. Unplug any connectors you had to remove during the mech work, make sure they are clean, reassembled correctly and tightly. Best of luck with it!

-Skip
 
Agree with checking the plug connections first.
By the radio buzzing and lights "dimming" it sounds like you have a ground wire that is loose somewhere and you are grounding out.
When doing the intake manifold, you may have loosened up one of the connections or when a harness was "laying" on the side, you may have cut into some of the outer coating and now it is grounding out.

Check your battery ground FIRST if you had to take it out, that is the simple place to start.
From there, it can be a real pain to find it. Every wire you can find that is attached to the chassis, make sure it is tight.
Good luck
 
When troubleshooting, Tony, you have two principal... ummm... principles to follow.

(1) What did you screw with last?

and

(2) What do the symptoms have in common?

Ground wire connection is the first and best suspect, as it could easily fit both categories. Also, since you were all "bull-in-a-china-shop"-ing around in the underhood region, you should look around for wires and connectors loosened.
 
Along with the idea of ground wires, look at the path of all wires within the engine compartment. With all the metal components moved and forcing various wiring assemblies out of the way, one may have become in inadvertently grounded upon reassembly, e.g., shorted... to ground.*

Just make sure those passing near assembled metal items are clear as necessary and none have ended up under a screw or bolt.

*It's like fingers on a chalkboard when I hear "shorted" as a term used to describe electrical problems. There may not even be power available at all but it's still "shorted." :rolleyes:
 
Also the headlights slightly dimming when the brake lights go on may be normal.

Otherwise, what they said.

~ Christopher
 
Yep, nothing more to add here at this time. Let us know the results after checking/securing all grounds.
 
tonycondon said:
Background- Matt Sawhill and I met at Matt Michaels heated garage this morning and spent the day putting new intake manifold gaskets on my car's engine. that went quite well and everything on the engine side of things is working well. amazingly we got the whole thing put back together, and it runs, with no empty holes or spare nuts/bolts!

Problem - On the 3 hour drive home tonight I encountered a few electrical issues that seemed to repeat but were not repeatable.

1) switching from low beam to high beam, occasionally the radio would skip or buzz a bass tone for a half second or so. One time I managed to kill the radio and panel lighting, and get the airbag light to flash, just by switching from low to high beam. switching back to low beam, then high beam returned everything to normal. engine ran perfectly throughout the episode.

2) when using the brake to slow from cruise control, headlights would slightly dim (may be normal, can't remember)

3) after arriving home, turned key off and all electrical shut down. usually headlights stay on and interior light is on when door is open. car would not start, as if the battery was dead. 1.5 hours later i went out and everything worked fine, car started. piece of cake.

any ideas?

Im sure we bumped a wire loose or something during the major dissasembly and reassembly required to get the intakes removed. now just to figure out which wire. I will be pulling the car into my parents heated garage tomorrow to take a look at it, appreciate any insights.
Click to expand...

You have a corroded or damaged ground strap, or possibly you forgot to hook it up to the engine when you put the manifold back on. There has to be a ground going from the engine to the battery, and one that links in the chassis. Often times this is a braided strap that goes from one of the manifold bolts/studs to the firewall. Make sure you have all of the connections, and that they are in good condition. You can experiment by hooking up a new set of grounding straps and seeing if the problem goes away.
 
thanks everybody, ill check it out tonight and let you know what i find
 
Skip Miller said:
Probably right. Just take off the intake manifold and re-install, being more careful this time!:rofl::rofl:


Good one! HA HA. (especially funny having seen what these guys went through)
Click to expand...
 
since you were all "bull-in-a-china-shop"-ing around in the underhood region,

Oh I like that too!

There were TWO bulls under the hood china shopping and 2 bull-**itters standing around watching so anything could have happened. In fact, it's a miracle the thing works at all.


MM
 
wby0nder said:
since you were all "bull-in-a-china-shop"-ing around in the underhood region,

Oh I like that too!

There were TWO bulls under the hood china shopping and 2 bull-**itters standing around watching so anything could have happened. In fact, it's a miracle the thing works at all.


MM
Click to expand...
yes nothing like guessing at how something comes apart and goes together while taking potshots from the peanut gallery
 
tonycondon said:
yes nothing like guessing at how something comes apart and goes together while taking potshots from the peanut gallery
Click to expand...

somebody had to do it Tony.
Make Matt fix it now since he got the "over all" picture by standing back.

:rofl::rofl::rofl:
 
markb5900 said:
somebody had to do it Tony.
Make Matt fix it now since he got the "over all" picture by standing back.

:rofl::rofl::rofl:
Click to expand...

haha. well he did do a nice job of keeping us supplied with a hot fire and coffee/hot chocolate.
 
If it's cold up there tony. Find a heated "self serve" car wash, pull in there, close the doors and have someplace warm to work on it.
 
markb5900 said:
If it's cold up there tony. Find a heated "self serve" car wash, pull in there, close the doors and have someplace warm to work on it.
Click to expand...

my parents heated garage will do the job. clever idea though lol
 
Make Matt fix it now since he got the "over all" picture by standing back.

:rofl::rofl::rofl:[/quote]

I already know what's wrong with it. I'm just chilling and wondering when he's going to figure it out.
 
wby0nder said:
Make Matt fix it now since he got the "over all" picture by standing back.

:rofl::rofl::rofl:
Click to expand...

I already know what's wrong with it. I'm just chilling and wondering when he's going to figure it out.[/QUOTE]

Remember that on the next rating Matt wants you to teach him Tony!

:rofl:
 
Got the car in the garage today. Couldnt find anything obviously wrong, but it seemed like the positive terminal on the battery didnt really get tightened down. got a vice grip on it and made sure it was snug. traced the ground to the engine/transmission and it was fine. all other connections were good. drove around for a while and it seems we are back to situation normal. other bonus is the coolant level is stable and the new gaskets are not leaking.

wby0nder said:
I already know what's wrong with it. I'm just chilling and wondering when he's going to figure it out.
Click to expand...

After checking everything over i figured there's a 10% chance that Matt was actually telling the truth, so i called him up. He answers the phone saying "I actually don't know what is wrong with your car"

Picture 1 - my engine, with old gasket

Picture 2 - Matt wrenching down the lower intake. notice the 'persuador' laying there...
 

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tonycondon said:
After checking everything over i figured there's a 10% chance that Matt was actually telling the truth, so i called him up. He answers the phone saying "I actually don't know what is wrong with your car"
Click to expand...



:rofl::rofl::rofl:

I can just hear him saying that, too!
 
markb5900 said:
If it's cold up there tony. Find a heated "self serve" car wash, pull in there, close the doors and have someplace warm to work on it.
Click to expand...

Yeahbut, it's not so warm once you come out with all of that water on you...and the soap can get in your eyes. :D
 
mike - not every carwash in the world is automatic

getting a CFIcast out tonight? :)
 
KennyFlys said:
*It's like fingers on a chalkboard when I hear "shorted" as a term used to describe electrical problems. There may not even be power available at all but it's still "shorted." :rolleyes:
Click to expand...

Nice to know I am not the only one. I hear the term "shorted" used exactly as you describe it and it drives me wild.
 
Don Jones said:
Nice to know I am not the only one. I hear the term "shorted" used exactly as you describe it and it drives me wild.
Click to expand...


That is one of my pet peaves. I'm an electrical / electronic guy for a living so I know the difference between a short and an open.
 
tonycondon said:
Picture 1 - my engine, with old gasket
Click to expand...

I would start it up and have someone wiggle all the wires that are in the vicinity of where you were working/leaning over/setting tools & parts down on....while watching the gauges, testing the things that are giving trouble.
Try to stay away from the secondary ig wires!
 
Let'sgoflying! said:
I would start it up and have someone wiggle all the wires that are in the vicinity of where you were working/leaning over/setting tools & parts down on....while watching the gauges, testing the things that are giving trouble.
Try to stay away from the secondary ig wires!
Click to expand...

And the fan, belt and any other moving parts! :hairraise:
 
yes the battery is a side terminal. the issue was we had just hand tightened the positive connection, after snugging it up with my favorite vice grips everything was, and is, happy.
 
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