electrical dilemma

clay fugate · #1 (**permalink**) 10-22-2001, 07:03 AM

ok guy's, here's the problem.
lonestar classics 427sc 351 windsor,
all electrical works fine, suddenly the right rear lights go out when head lights are turned on. the turn indicator works, the brake lights work, the bulbs have been switched to other side, they work fine, and the ground to the frame has been checked, and seems fine. where else could the problem lie?

Flyin_Freddie · #2 (**permalink**) 10-22-2001, 09:52 AM

I'm not a Lonestar owner, but I know a little about electrics. Did ya check your switch? It sounds like a grounding problem, but if you checked your body to frame connection and you're sure it's good, then I'd check the components themselves. Sounds like you've already checked the brake/tail lights. I'd look at the switch first, though. It's the only mechanical device in the loop, and chances are the switch has gone bad and causing a short or intermittent ground connection. Have you changed anything recently with the headlights...?

I'd suspect the switch first...just from experience.

clay fugate · #3 (**permalink**) 10-22-2001, 12:07 PM

no, i have not looked at the switch yet. does the switch generally have separate leads on it for each side of the car?

clay

Flyin_Freddie · #4 (**permalink**) 10-22-2001, 02:46 PM

Can't say for sure, but I have seen switches with separate connections for each side of the car. One would think there would be a terminal connected to a relay, then the relay would be connected to the circuit and to the load (lights, etc.). But, I've seen separate terminals for each fusible circuit, ie: right side of the car versus left side.

Check the switch and see if any terminal is touching another and causing the short. But BE CAREFUL, the terminals are hot even with the ignition switch off in most cars. You can cause a real fireworks show if you're not careful. Make sure you've got some spare fuses on hand...you'll probably need 'em....ask me how I know this!

If you can't find the problem in the switch, disconnect one terminal at a time to troubleshoot. If something else goes off and stays off, then that's not the bad circuit. Eventually, you'll get to one that makes no change to your problem - THAT'S THE ONE! Then all you've got to do is figure out what's wrong with that one...I'd bet it's touching another terminal and causing a back circuit, short, or ground problem.

Frustrating as hell, I know, but I don't know of another way. Start at one end of the circuit and test until you get to the end of the circuit...jumping around will cause your to lose your mind...don't ask me how I know about THAT one either!

Don't forget about the fireworks show...it will happen...trust me!

clay fugate · #5 (**permalink**) 10-23-2001, 06:34 AM

thanks for the info, i'll start on it tonight, i'll keep the fire extinguisher, and plenty of bud light handy for any firework mishaps. i'll let you know how it turns out.

clay

Flyin_Freddie · #6 (**permalink**) 10-23-2001, 07:44 AM

The probability of an unintended fireworks show varies proportionately with the amount of Bud Light consummed. In fact, it's been mathematically proven to be almost a one-to-one ratio. Scary...but true.

clay fugate · #7 (**permalink**) 10-23-2001, 08:21 AM

in that case, i will have a case of fire extinguishers!!

clay

Dominik · #8 (**permalink**) 10-25-2001, 03:18 AM

Clay,

I had exactly the same problem. It was the switch which is supposed to bridge the cicuit to the rear lights when changing from parking lights to driving lights.

The rear lights are (usually) connected the front parking lights as well. Check if they (the small) bulbs are off also when the driving light are switched on.

Mine was an old LUCAS swich.

Dominik

Flyin_Freddie · #9 (**permalink**) 10-25-2001, 01:16 PM

Ahh.....Joseph Lucas, the "Prince of Darkness" rears his ugly head again!

Y'know, there's a poster on the wall in the Lucas factory. It reads "Work Hard and Get Home Before the Sun Sets". There's a reason that's posted in the Lucas factory.

Anyone know why the English drink warm beer? Yep, it's 'cuz Joseph Lucas makes refrigerators, too.

Some of the screwiest electrical problems I've ever solved involved Lucas electrics. Scary stuff...driving down the road one night in an MGB-GT I used to own, hit a bump - all the lights went out...I mean everything...TOTAL darkness! I tried to hold the wheel straight and stomped on the brakes. Hit another bump, and everything came back on again. No problem....drove on home with no further problems. Looked for a short, loose connection, bad ground - ANYTHING - for over two weeks. Never found the problem and it never happened again. Weird.... Gremlins... Who knows...?

Had another problem with a secondary wire to the distributor. Under load the car would run fine, but if you took your foot off the throttle, the car would die - but before it would totally stop, it would rev up again and then die, then rev up again. All this without touching the throttle. Put your foot back on the throttle and start to accelerate and everything was Jake...worked fine. Take your foot off the throttle and it would die, then rev up, then die, then rev up...DROVE ME NUTS!

Turned out to be a broken wire INSIDE the insulation. It was the secondary wire that went to the ignition points. Under load, the vacuum advance would relieve the tension on the wire because the plate would move as the ignition would advance. Once the tension was relieved, the car would run just fine. But, take your foot off the gas, and the vacuum would reduce causing the plate to retard, thereby placing the wire under tension again, breaking the connection and killing the spark. Then, the plate would return as there was NO vacuum and the wire would make connection, the fires would light again, and the engine would rev up....until of course the vacuum increased to the point where the plate started to advance again and we'd begin the vicious process all over again! It would Rev up, then almost die, then rev up, then almost die. Did that for two weeks until I could find the problem. Just stumbled into it using a volt-ohm meter and checking connections. I saw the needle flicker a little while testing this wire. But, I could only make it fail when I forced the ignition to advance. I finally determined the wire was broken...removed it and confirmed it was indeed broken inside the insulation. Replaced the wire, and the problem went away.

I could have KILLED Joseph Lucas...!

It's funny NOW, but it certainly wasn't then. I lost both hair and sleep over that one...what a nightmare!

Dominik · #10 (**permalink**) 10-26-2001, 12:42 AM

Freddy,
what I nighmare ...

LUCAS: "Princess of the Dawn - Accept"?
But you know: it builds character.

Vehicle electrician? It's a lousy job, marginally paid at best. No honors. Try the to explain the problem you experienced to the customer when you present the invoice listing 2.34 billion hours needed to find the gremlin - if you find it!

That's for labor. Todays cars call for multibillion $$$ for spare parts also ...

Lousy job. I was vehicle electrician before. Changed to project mangement now: lousy job - again, also no honors but well paid ...

Dominik

Okiesnake · #11 (**permalink**) 10-26-2001, 08:34 PM

Clay,
There are 2 different elements in each bulb. They are not the same. If you get them switched, you can get the symptoms you describe. Check both your right front and your right rear. Either or both of them could be the problem (front or rear). The connection pad that the bulbs contacts can get pushed in and rotated 180 degrees and therefore be switched. One element burns brighter than the other. The one that burns brighter is for the turn signal on the one set and the brake lamp on the other set. The ones that burn dimmer is for the Parking lights.
Hope this helps - Okiesnake

Dave Samson · #12 (**permalink**) 10-26-2001, 08:37 PM

Dominik,

Will your next job be the ice cream vendor on the beach ?

Jack21 · #13 (**permalink**) 10-27-2001, 12:00 PM

Couple of things to look for. Have CR, not Lonestar, but electrics on these should be fairly similar.

Your headlight switch has a parking light out terminal, and headlight out terminal. The parking lights should be hot in park, and hot in headlights. If the parking light out goes dead when you switch the headlights on, the switch is bad. Either replace the switch, or make yourself a little jumper from the headlight out, back to the park out with a 3 amp rectifier (diode) from Radio Shack for about a buck.

If you're using Lucas round Healy style lights, here are a few tips.
The black ground wire is only crimped in place. When it corrodes, and it will, no ground. Unroll the crimp strap, drill a hole in it big enough for an 8-32 brass screw, solder a terminal onto the ground wire, and install it onto the light with the screw. Then put a thin coating of wheel bearing grease on it and reinstall. Put small amount of grease on little brass tits that hold the lens in place. Prevents dissimilar metals corrosion between brass and steel, or you'll be replacing rusty lights every couple of years.

Another tip. Redundant grounds. Wire all your frame grounds additionally back to a central connecting point like a brass strap, then connect directly to battery ground lead. Starter solenoid frame is a good place to do this. I put a brass strap on the inside and outside of the firewall. Ron Francis Wireworks has them or you can make one. It's a lot easier to do this while you're wiring everything, than trying to diagnose them when they corrode later.

clay fugate · #14 (**permalink**) 11-01-2001, 07:20 AM

FOUND THE PROBLEM, AFTER DAYS OF RUNNING WIRES AND CHECKING GROUNDS, SWITCHES, POWER, PULLING MY HAIR OUT, ETC.....
I FOUND A BROKEN WIRE INSIDE THE TAILIGHT SOCKET, WHERE THE WIRE IS CRIMPED TO THE SMALL BRASS CONNECTOR WHICH TOUCHES THE BULB. I CHECK THAT FREAKIN WIRE TEN TIMES FOR VOLTAGE, BUT NEVER ACTUALLY TOOK THE RUBBER BOOT OF THE SOCKET. I GUESS I FIGURED IF IT HAD POWER TO THE BACK OF THE BOOT, IT HAD TO GO ANOTHER 1/2 INCH ALL THE WAY TO THE BULB. CHEAP BASTARDS! WHAT A HEADACHE.
OH WELL, THE BEER FLOWED AFTER THAT FIND. NOW MY HEAD HURTS FOR ANOTHER REASON.

THANKS TO ALL FOR YOUR EXPERTISE
HAPPY MOTORING!!!!

CLAY

Flyin_Freddie · #15 (**permalink**) 11-01-2001, 08:19 AM

See...? It was one of the components...just like I said in my original reply: "...but if you checked your body to frame connection and you're sure it's good, then I'd check the components themselves." I would have suspected the switch, as I already wrote, but hell, I doubt I would have checked for a broken wire inside the tail light itself! Bet that did drive you crazy...'specially through that beer-induced haze!

Well....a good ending to another electrical saga. Hope you remember what you learned in this process. Electrical problems are seldom real difficult to fix, once you find them! Finding the source of the problem is usually 95% of the time involved! Re-read Dominik's post about presenting the customer with a bill for 2.4 billion hours....it's more real than most folks imagine.

Except for Cobra-philes, of course....