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A possible electrical headache on the way...

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Midget78

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When I purchased my 78 Midget the tach would work when it felt like it (jumps every now and then), the gas gauge doesnt work at all (sits on "E"), the horn doesnt work, the curtesy light, cigarette lighter and radio dont work. The gas gauge Im sure is the sending unit needing torn out and replaced. The tach Im sure has a wire that needs addressed. But the horn, curtesy light, and cigarette lighter is the one that has me stumped. The previous owner put an after market radio in with Clarion speakers yet it doesnt turn on. Im wondering if a ground wire or something in there is not grounded right. I checked the fuse box and all fuses are good and the wires there seem to have good connection. Im not so concerned about the curtesy light or the cigarette lighter, yet the horn I would like to work with some of the crazy's out there that act like they dont see me coming. Electrical I know can be a real headache and honestly I dont know where to even start. I guess I need to determine what circuit each component is on or possibly if they are all together. Any tips or suggestions?
 
Yep, you need a wiring diagram to see if everything's on the same or different circuits....Lucas wiring problems, unless a DFPO has been messing with them, is usually a bad ground or corroded connector...I'd start by removing the fuse block from the car completely, cleaning it up & reinstalling....then, I'd start taking every connector apart & cleaning them with a spray-on electrical contact cleaner....up under the dash there are grounds you want to check & (though they look good) go ahead & replace all the fuses.
 
OK, just looked at the chart and I would go back to your fusebox. Horn, Cigarette Lighter and Courtesy light are all fed from the Purple (fused/unswitched) The radio shouldn't be - but I wouldn't be surprised if they haven't pulled a feed. (did the radio work with the car off?)

Anyway, the purple seems to ground on the driver's side front - there should be a cluster of black wires attached to the inside fender body just about beside the fan belt. However, the horn is grounded through the horn push (not there) making the power feed the more likely culprit.

Check the connection (purple wires/ top left) - clean, tighten & dielectric grease. Make sure the fuse is OK and that there is continuity across the fuse/ fuse connections.

You might be pleasantly surprised.

Tach might just be the connection - pull the white/black wire off the negative side of the coil - clean and tighten as above and see what happens

let us know!
 
A copy of a wiring diagram is the first place to start but morethan likely you've got a case of the green stuff on all of your contacts, especially in the Fuse Block. Fuses may be good but that doesn't mean to contacts in the fuseholder are not oxidized / rusted up and incapable of passing electricity.

Start with the simple solutions and take a piece of crocus cloth / fine 400 grit paper to the sides of the fuseholder. Since so much stuff is not working I'll bet that is half of your problem.

When I got Bugsy my '68 almost 9 years ago, absolutely none of the instruments or gauges worked, no turn signals, brake lights, headlights etc. I started working through the wiring harness with a VOM and determined I have electricity here, do I have electricity there? type analysis scenario. In virtually every case, I was able to clean up and polish all of the electrical connections and everything started working again.

Of the two fuses in the fuse box, 1 supplies power all of the time and the other is switched, only works when the key is on.

Trouble shooting the radio, isolate the power wire and the ground and connect directly to the battery or to the solenoid, there is a terminal there that comes directly from the battery and is always on. Make sure power fuse is good on the radio and hook it up to see if it at least lights up.

Simple trouble shooting is the way to go. Someone on here will provide a link on where you can get a color coded wiring diagram wiring diagram for your car. Take it to Kinkos, blow it up big time and laminate it and hang on your garage wall for reference. It looks complicated but after a little bit of cogitation, and brake cleaner applied with a paper towel to clean up the what color is that wire anyway, condition of wires in the harness, you can get this one going.

Ask and we can help.
 
Yo, Sweendog... do we have the same car?? You seem to have the exact same issues I do at the same time... These guys out here totally nailed my problem. Here is the thread:

https://www.britishcarforum.com/bcforum/u..._a_f#Post552396

Let me know if you want the color wire diagram and I'll send it to you.
 
Midget78 said:
When I purchased my 78 Midget the tach would work when it felt like it (jumps every now and then), the gas gauge doesnt work at all (sits on "E"), the horn doesnt work, the curtesy light, cigarette lighter and radio dont work. The gas gauge Im sure is the sending unit needing torn out and replaced. The tach Im sure has a wire that needs addressed. But the horn, curtesy light, and cigarette lighter is the one that has me stumped. The previous owner put an after market radio in with Clarion speakers yet it doesnt turn on. Im wondering if a ground wire or something in there is not grounded right. I checked the fuse box and all fuses are good and the wires there seem to have good connection. Im not so concerned about the curtesy light or the cigarette lighter, yet the horn I would like to work with some of the crazy's out there that act like they dont see me coming. Electrical I know can be a real headache and honestly I dont know where to even start. I guess I need to determine what circuit each component is on or possibly if they are all together. Any tips or suggestions?
Click to expand...

Ah, a fellow Ohio Midget owner; you're actually not far away. Just an FYI on the gas gauge; mine had two issues. The instrument voltage stabilizer had given up the ghost, so I built a solid state replacement for it. I see that Moss actually came out with a solid state drop in replacement too. The other issue was bad connections at the sender. Trouble with that one is it involves dropping the tank to fix it, but I added a better ground wire to the sender too since there was no good ground to the sender body. The sender itself is probably OK. The connection to the gauge circuit was pretty rusty, so I cleaned it up, and put some dielectric grease on it.

My horns had given up the ghost completely; they wouldn't work at all and had to be replaced. Do the lights dim noticeably if you press the horn button?

The courtesy light is pretty simple; there are a couple of bullet connectors inside the dash to it, and you can see if it has power by flipping the switch on top of it. The door switches get dirty and don't always make contact.
 
Thanks for all of your feedback. Its a bit cold out there today but after reading everyones comments Im going to bundle up and get at it starting at cleaning up the fuse block and putting in all new fuses.
Ed, when I see your posts I always look into them because our cars are pretty close to being the same. I think the only difference is I have the 1500 motor. We seem to be working on the same stuff at times. Weber carb (oil blowing out of the dip stick), seat belts, brakes, etc. Thats what makes this forum so interesting.
I will check and see if the lights dim when I push the horn but I dont recall that happening. The sending unit in the gas tank is going to be my last job on the list since I have to drop the gas tank. I have a feeling I will have a few broken knuckles doing that job. Im lucky though to have an old car here in northern Ohio that the body is solid with no rust or bondo areas. I need to get the old paint off this year so that rust doesnt start to do what it does best.
Other interesting note, the guy I bought the car from gave me a box of parts and I never looked at it cause it looked like a lot of junk. I desided to get into it and found a starter that works, a tonnou cover that I was thinking about buying anyway, new light bulbs, new ball joints, new tie rods under all the old paper work and empty parts boxes. Kinda like Christmas in March.
 
Dog, my fuel gauge started working as soon as I (the guys here) fixed the wiring issue. Hopefully, it's the same for you. I wish I had known about this forum much earlier in the restoration process. I really could have saved some time, frustration, and money. I was feeling pretty alone in restoring this car. Now, I feel pretty powerful! She'll be running soon and I'm sure I'll have more topics to chat about.

Can anyone recommend a good electrical contact solvent/cleaner?

Thanks, guys!
:cheers:
 
Good old fashioned crocus/emery cloth / pencil eraser / contact cleaner in a can from Radio Shack.
 
Wow, I had a few minutes to get into it and pulled the purple wire from the fuse block. Cleaned the contact and put some dielectric grease on it. Got in the car and right away I noticed the "seatbelt light and buzzer" came on which means things are starting to work and that is the area in need of attention. I think Im going to pull the entire block, sit down with it and clean everything. Then put it back and see what I get. With the hood prop on that side it makes it a pain to bend into the engine compartment area where the block is at and work on it.
 
Well, the problem was entirely at the fuse block. Cleaned the contacts and now all is working except the radio and gas gauge. Im sure I need to get into the gas tank and the sending unit is crystalized. The radio is just plain shot. I'll get another one at some point and install it but I want to focus on the gas gauge first. I dont like having that spare gas in the can in the trunk. Anyone know where I can get a new and affordable fire extinguisher for my Midget that isnt to big?
 
Kmart, Wallmart, nice red ones.
 
The tach has got me scratching my head. Sometimes it jumps up and wants to work and other times it just plain doesnt move at all. I felt around back behind it moving the wires to it and nothing changed. I did notice when I use my turn signals, the needle jumps everytime the signal flashed. Weird. Any ideas on the tach doing that?
 
Ground to the tach is bad. I'm willing to put a bet on that one. There is a ground wire that attaches to back of the tach via one of the knurled knobs back there. You'll need to find a MOWOG, one of those legendary creatures who built these cars, to remove the knurled knobs and remove the tach. Same goes for the gas gauge wiring as there are daisy chained from one to another. The gas gauge is the worst to remove. My hands are too big to get in there and remove without pulling the dash. Rest of the instruments you can get at and cleanup the connections.

I found ground on the tank sender was all corroded as well. Once I cleaned up gauge started working again. Tank, when empty, is fairly light and easy to drop. 6 bolts to undo and it drops right down. Probably wouldn't be a bad thing to do to drop tank anyway and inspect. Usually lots of crud in there especially if gasoline became really old and dried up in there. Frank C. trick of boiling on the grill evidently works well. Read up on procedures to prevent accidental explosion of course.
 
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