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Topic: Sometimes I really hate electrical (Read 1636 times) previous topic - next topic

Sometimes I really hate electrical

So my 86 tbird has done this thing where the dash lights and heater randomly go out. Its been like that since I bought the car last year. When I first bought it, if you tugged on the steering wheel or pulled on it too hard, the car would die.

I thought no big deal, get a new ignition switch, call it a day. Drove it home no issue, and swapped in an extra switch. Couple of months down the road, hit a speed bump and the dash lights go out. Take the switch out, and the connector is melted. The dash is still readable barely, and it didn't really bug me, so I just kinda ignored it for a while.

Now that its getting cold again, I am running my heater alot, not to mention how much I drive, and I do pizza delivery, so I like to keep the heater going as I am mainly doing short trips, in and out constantly and its been in the low 20's, so a warm car isn't a bad thing.

One day the dash lights go out, and so does the heater. I special ordered the ignitions switch "pigtail" when I knew mine was melted. As I was getting ready to splice over the whole switch, I realized I didnt need to splice all of them. So I unpinned each one, looking really carefully for anything that's burned or melted. I don't find anything, nothing at all.

As a matter of fact, all the connectors look pretty much brand new. After putting it all back, everything seems to be fixed, I figured it just must have been the slightly melted connector.

Now remembering I hit a speed bump, or tug on the steering wheel, randomly it dies again. Well today it died all together. If I kept the heater off the dash would barely light up, so I left it off or low for the whole night.

Now when I get off work, its 16° and I've been cold for most of the night. I had another new switch and some 40 amp relays plus some wire I bought specifically to splice them in and slave everything.

I pull the ignition switch off, carefully pull each wire trying to decide which one is melted and needs to be slaved to a relay. The switch still looks brand new and all the wires and connectors are still perfect.

I spent two hours trying to figure out which wire was bad and found nothing wrong. About to give up, I tossed down my test light down in the console cubby thing, and I see a flash of light. After poking around a bit, the grounding part of the cigarette lighter is powered. I hadn't even noticed, but every time I turn on my heater, my cigarette lighter dies.

To test it, I clip on an alligator clip to the outside lip of the cigarette lighter then ground it to the colum. Instantly the heater comes on, as well as the dash light. After poking around, the whole s902 grounding point seems to be dead. After another hour or two of trying to figure out where a "centered on the I/p panel" is, I stumble onto it and realize its somewhere near the radio bolted to the side of the dash.

After poking around for a bit trying to trace back to it from the cigarette lighter, I gave up, and added a t-splice to the lighter ground and bolted the other end to the dash brace on the steering column.

I feel like an idiot for blaming the ignition switch this whole time when it was just a random ground, probably just loose or dirty somewhere under the dash.

First warmish day i have off, I am gonna go any try to find that ground and see if I can replace it.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Sometimes I really hate electrical

Reply #1
Sounds like it is fixed to me... As long as the conductor(wire) is large enough to carry load without significant voltage drop, source of ground isn't going to make a difference...

For dash lights are you talking general illumination or specific indicators??? The ign sw has zero to do with general lighting, only warning lights and such would possibly be affected by that...

Sometimes I really hate electrical

Reply #2
I find it hard to believe that the LCD Speedo turns on with the ignition switch, but it somehow doesn't power or isn't effected by it.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Sometimes I really hate electrical

Reply #3
Quote from: Haystack;463971
I find it hard to believe that the LCD Speedo turns on with the ignition switch, but it somehow doesn't power or isn't effected by it.

Sorry, didn't mean to imply such wasn't controlled by ign switch, I was speaking of regular dash lights... I've changed the bulbs in one of those, that was over 20 years ago...

Sometimes I really hate electrical

Reply #4
I have sometimes wondered how that instrument cluster ground got connected back to the body of the car. Are all of the screws that mount the dash metal on metal? Or are some of them plastic on metal? Do they screw into threaded holes in the car body or are they those clip type things?
I have never removed the dash. That's why I have so many questions.

PS. How many screws are there?  If they have been left out would the dash stay in?

Sometimes I really hate electrical

Reply #5
I've had 20 screws left over before from a heater core swap, in my younger less caring days. Theres probably around 60 or 80 if you were to remove all of them.

Most are body clips with regular style Philips, then there are a few bigger ones with hex heads, about 10mm if I remeber right.

Basically every part of the dash screws into a large metal frame that braces rhe back side of the dash. This is also what the pedal cluster and steering column bolt to under the dash. This is what you remove when doing a heater core to get enough wiggle room.

And yeah, I've changed my fair share of dash lights over the years. If you have a console, it nearly doubles the amount of screws to keep track of vs the 85-88 mini console attached to the seat.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Sometimes I really hate electrical

Reply #6
Quote from: TurboCoupe50;463972
Sorry, didn't mean to imply such wasn't controlled by ign switch, I was speaking of regular dash lights... I've changed the bulbs in one of those, that was over 20 years ago...

Yeah, the backlight comes on in accessories or the run position. When you flip on headlights, it actually dims the lights slightly. Eric has a write up on how to wire it to stay brighter with the headlights on.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com


Sometimes I really hate electrical

Reply #8
Sometimes I look really good stumbling onto easy fixes. I actually enjoy reading wiring digrams and troubleshooting, just not broke down on the side of the road or when its cold. But being so sure that it was a bad ignition switch clouded my judgement and critical thinking. Wasted hours troubleshooting a problem that wasn't there and ignoring the actual symptoms.

Btw, heater worked flawlessly all day today, 245 miles and about 6 total hours of driving. My gauges also have stopped randomly pegging as far as I can tell, somehow they must be related to that ground. Phone chargers (I have about 9 total, two dashcam, one Qualcomm "quick charger" for my phone, double quick charger in the console for usb batteries and passengers, plus four occupying the rear console ashtray to charge up my kids tablets and extra usb batterys as well hooked up to a trick 4 way splitter with a relay on off switch)all seem to be charging much quicker.


But.... Dash display back light is back to being intermittent. Pretty sure its a separate issue. This is my 11th v-8 car, only one wasn't a 2.73 gear and aod combo, I could tell my speed blindfolded if I had to. Once it gets dark, its readable, but the odometer is practically invisible when the light goes out. Makes it hard to estimate mpg.

Oh well, on to fix a few smaller things when it gets nice enough outside. I broke my read window defroster connection off with a paper towel wiping down the back window, that's gonna get annoying if snow ever hits the ground. Plus the idle is really funky, I just raised it so the car won't die temporarily, but its one of the small things that drives me nuts. Then I gotta do a tune up and maybe an oil change. I think 30k miles is enough life out of that oil filter.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Sometimes I really hate electrical

Reply #9
Quote from: Haystack;463980
I think 30k miles is enough life out of that oil filter.

Ahhh Hell changing oil filters is overrated, though I don't run one over 10K mi...

For digital dashes I've never owned a car with one that wasn't earmarked to flip, neither of my Grand Marquis have one... Having serviced electronics for over 50 years, I know by 20-25 years that stuff has turned to ... Recently re soldered odo PCB connections in a friend's Harley Davidson F-150, also clock connections in his work F-150... Both are around 15 years old... 

BTW the dash in his HD F-150 needed some new bulbs, Joe said he found they were dealer item only, cost him like $10-12 apiece... Now that's BS... I'd have rigged some #194... Twenty years or so ago I did exactly that in a XR4ti that had some odd german bulbs...  All but one was dead & dealer want $5 ea(or something close)... I took the assemblies apart and soldered #194 in them...