Bad news - I don't know what I did wrong so if I just replace the wire it may happen again. Here is what I did. I put in a new gas gauge from CP (which, BTW, is the second one and they replaced the first one without question - good guys) and that was the only think that I changed since the last outing where everything seemed fine. The ignition key was off and I slipped the negative wire back on the neg terminal post and notice there was some sparking, then there was the smell of plastic burning, then there was smoke then there was me burning my thumb removing the neg wire ASAP. Oh yeah, I said a bad word when the nerve endings in my thumb sent the message to my brain that I had just roasted my thumb. Anyway, the melted wire is the one that goes from the Starter motor to the Ammeter neg terminal. It is a heavy gauge wire. According to the wiring diagram it goes from the "B" terminal on the starter to the neg terminal on the ammeter. How do I figure out what caused this and correct it before I burn my replacement wire? Please make your answer suitable to a third grade mind. Maybe that way I will have a chance of understanding it. Thanks as always, Gater P.S. Zig, if you have the answer let me go ahead now and say I am sorry for the bed envy comment.
I'll throw my thoughts in, but I'm not a real expert on the wiring on these trucks... First off, it sounds like something in that wire is grounded out, causing a short in it. Since most ammeters are not fused you burn the wire rather than blowing a fuse. I haven't looked at the old wiring diagrams (and I ripped all the wiring out of my truck so... Do you think this wire was bad? Maybe touching some metal where it passes through the firewall or something like that? If you have no clue why this is happening and before burning up your replacement wire you may want to try a local parts house. Get a inline fuse holder (which will have wire pigtails and a new style fuse included). May want to get a few replacement fuses as well. This and some wire (same size as the one that burned) to make your own wire for the moment. This way you can troubleshoot without hurting your harness or other original wiring. Something may have shorted in the starter solenoid, tho I don't recall ever seeing that before. What else have you changed or when did this first start? I doubt the fuel sender would have caused it...but its suspect since you just installed it. Now that I think about it, doesn't the "B" terminal on the starter power the entire truck? Basically everything runs thru the ammeter. So perhaps the short is somewhere else, and it could be anywhere if this is the case. You may want to look around and see if any other wires have issues. Anyway, let me know what else you've done recently and I'll try to help...at least until more knowledgeable folks hop on. And a fuse between the battery and the rest of the truck is a good idea on any vehicle...especially with an ammeter. If one short happens the whole harness can get damaged... Andy
Assuming you don't have a schematic or don't know how to read one and don't know how to troubleshoot an electrical system with a volt/ohm meter I'd suggest you do this: Remove the positive connection from the battery. Connect the negative connection to the battery. If you don't have a test lamp head to FLAPS and buy a lamp socket with wire pigtails (tails, that is 2 wires) for a single element lamp and a lamp to fit into it. Even better if you can find one is a back up alarm that beeps when you put your car in reverse. With the key off and all fuses removed from your electrical system connect one wire of the lamp (or back up alarm) to the positive battery terminal, the other wire to the positive battery cable. If you are using the beeper you need to attach the + wire to the battery, - wire to the cable. Did the light go on (or the beeper beep)? Yes - start disconnecting circuits until it goes off/quits beeping. When it stops the last disconnected circuit is at fault. Let the gang know what that circuit is (what you last disconnected) and we will help you figure out what is wrong. No - start plugging the fuses back in one at a time until the light/beep occurs. When it does, remove that fuse and continue with the others. Again, let us know which circuit and we should be able to help you. Why is the beeper better? Because you don't have to have a helper watch the light when you are somewhere you can't see it. The lamp/beeper will limit the current flow to an amount small enough to let the smoke stay inside any wiring or electrical components. Getting the smoke back inside once it escapes is a real hemorrhoid.
Gater, I've looked at a few wiring diagrams this afternoon and everyone of them show the wire going from the starter motor to the pos side of the ammeter. I'm not suggesting, however that you take the above statement as gospel, merely that this is what i'm seeing.
Really sorry to hear this. I've fried two new gas gauges now. I went ahead and hired out the rewire job. Now I can not find the schematic so I'm frying gas gauges. Is your kit for a positive ground? That truck of mine was a positive ground. (How does one post photo's here?) Charles (ccharr) '48 3804 registered as a '47 or so the VIN# indicates
Thanks for all the replies. SWMBO drug me out to a play tonight. At least it was "Tradin Paint" about Nascar. It stereotyped us hill billies and I was sitting next to an obnoxious yankee (no, I don't consider that redundant) but other than that I had a great time. I am going by the instructions that came with the harness when I say the B terminal on the starter to the ammeter neg. I don't have a solenoid if I have the old floor pedal starter linkage do I? I am going to follow Bill's steps first but I have one question, Bill. When you say disconnect the circuits one at a time but I have already taken out the fuses, how do I disconnect the circuits? I thought taking out the fuses was the only way to disconnect a circuit on one of these. As you can see, I am not adept at troubleshooting electrical on a car. Thanks, Gater
Dead Short ! ...Is what you have when the wire cooks and lets the <magic> smoke out . O.K. , You need to remove all other wires from the ammeter (one post has two) and then brush a hot lead from the battery to each ammeter post , it should _not_ spark . reversing the ammter leads just makes it read backwards , won't cause it to spark , O.K.? . If it sparks , the ammeter is grounding , might be slightly crooked in the pod...? . No spark ? O.K. . now test the other big fat wires that're supposed to be connected to the ammeter and see of one makes sparks or clicks a 30 Amp ciruit breaker you've installed as a safety ~ if one does , I wonder if maybe you've crossed the regulator wires as that'll do it . Use a cheapo Motocycle horn or 30 amp . circuit breaker in the hot line to test , if it's shorted you'll hear the horn toot ot the breaker popping . Don't worry , it'll be something simple , electrical always is , that's why I like it , it's easy .
Thanks, Nate. It might be a day or two before I can troubleshoot since I have open house at school and karate for my son and ..... Anyway, I had taken the ammeter out to put in the new gas gauge so I might have grounded it somehow. I also put in a new headlight switch but I have driven it quite a bit since then and no smoke. The wiring is all new (fairly) so I don't think it is shorting against the firewall. I will do as you say, sir. Thanks again, Gater Your post time shows here as 2:04 AM. I hope you aren't going sleepless again.
Actually I got a solid 4 hours of sleep last night . I rarely sleep more than 20 ~ 40 minutes so that was good , we'll see if it was enough my brother came by last night and we went out to a musical magic show ~ wierd but fun nontheless .
Not all circuits are protected by fuses. Typically the starter wiring and the ammeter are not. Assuming you have the test light (or better yet a noise maker of some kind, Nate suggested a motorcycle horn, I like a back up alarm) connected between the positive battery post and the positive battery cable, what I meant by "disconnect the circuits one at a time" is basically what Nate described. Remove the battery side wire from the ammeter. Does the light/horn/beeper quit? No - then the problem isn't in any circuit that doesn't go through the ammeter. I'm not positive, but that would probably limit the problem to the starter circuit. Yes - put the battery side connection back onto the ammeter and remove the connections from the other side of the ammeter. Did the light/horn/beeper quit? No - the ammeter itself is causing the short Yes - put the wires back onto the ammeter one at a time until the light/horn/beeper turns on. That wire is the circuit that is cauing grief. When you get this far along you will either be the group's new electrical expert because you have figured out what the problem is or will need additional help. In either case let us know.
Warning ! DO NOT leave a fuse or circuit breaker in the primary circuit wire when driving! (the always live one) as it'll blow under a normal surge leaving you stranded . If you used , say a 60 Amp. breaker and it tripped then reset , this would almost certainly fry the voltage regulator or the diodes (if you have an alternator) as the resultant " spike " in charge current will arc. the points in the regulator (generator equipped) or blow the diode - trio (alternator equipped) There's a reason these things don't come with charging system fuses . Modern cars have " fusible links " that literally burn to a crisp in dire circumstances , I don't like 'em .
I never knew an ammeter had a neg and pos terminal. It's all in the positive side of the system so I always thought there was just a right way or backward. Having "neg" on one terminal could lead to a bad situation if someone hooked a ground to where it reads "neg". A quick and dirty way to test is to take your wire from the battery (starter terminal) and bypass the amp gauge by touching the wire(s) that would normally be on the other terminal of the amp gauge. If sparks--not the gauge; if no sparks--is the gauge. Either way, just a quick arc and DON'T HOLD TIGHT WITH YOUR THUMB.
Fire!!?? AAAAAAHHHH! If the big wire from the starter to the ammeter burned, you have a big short directly to ground. My first thought is that the little paper gasket that isolates the ammeter post from the guage housing is missing, which means a direct short. I suspect something along those lines, possibly the wires touching the body somehow behind the guage. If the wires were backwards, the ammeter would just read backwards. You have a big short! Inspect very carefully, and be carefull hooking the wire back up, as that it a large wire that can flow a lot of current if shorted! Good luck.....Mike
Big smoke... not the kind you remember from college either. I have picked up my wire but have been so busy that I haven't got into it yet. Since I had to take the ammeter loose to get the gas gauge in I suspect that the what Mike said is true. I probably did something simple like letting the wire touch or letting the paper slip. We shall see. Gater
Alright, I tore into it and here is what I found so far. No troubleshooting yet, just a tear out to see what I have. The only thing that is melted is the wire from the battery terminal on the starter to the neg post on the ammeter. There is no sign of burnt metal on or around the dash cluster. The piece of paper that goes between the dash cluster and the terminal ends was in place and not scorched or anything. So, I still don't no what made the smoke come out. Here is a little more info on my system. I have a 12 volt system with a pedal starter and an alternator. The wiring harness came from CP and the instruction are thus: Ammeter (+ terminal) to Fuse Block (horn terminal left) Ammeter (+ terminal) to Alternator (screw lug terminal) Ammeter (- terminal) to Starter Motor (B terminal) This is the way I have always had it and not had a problem before. The only other electrical that I have done recently was a new headlight switch but I have run the truck quite a bit since then with no problem. However, I have noticed that, before the headlight switch was replaced, I never got any sparks when reattaching the negative on the battery. After, I would get slight sparking. Of course, when the smoke came out it sounded like I was frying an egg when I put the neg wire on the battery. I will now rewire everything and go through the above listed diagnostics before trying to hook the battery back up. Gater
Follow-up. I replaced the heavy wire from the starter B terminal to the ammeter and the small wire from the coil to the ignition (it was bundled with the heavy wire and the insulation was melted off of it too). It must have been something simple like the ammeter post grounding to the gauge cluster because once I rewired and tested, all was well. I drove the truck with my wife and son in the Labor Day parade in out town whose population is 850. There were a lot of comments on the truck ranging from how good the paint looked to where did I get the wheels to I am glad you took it back to original and I have never seen a bed like that. A good time was had by all. This was one of the things that I had always wanted to do since I bought the truck in '89. Another milestone reached. I want to thank you all for your comments and advice. This is truly a great forum, especially when we stick to talking about our trucks. Gater
If I understand this correctly, it sounds to me like the fuse block (and any devices attached to it) will not be measured by the ammeter. I think that the feed to the fuse box should be on the - side of the ammeter. Simple test: With the key on and the engine NOT running, turn some device that is fed from the fuse box on and off repeatedly. Does the ammeter react? It should go more negative while the device is on, less negative while it is off.
Thanks, Bill I did switch the wires so they are as you say. I will try the test tonight and see if it does change. Gater
