All Systems Dead-1970 Gt

[scodari]

I was working on getting the headlights to flip correctly.....finally got that fixed and tried to test the headlights only to find that all systems were dead...nothing works.

From what I have read, it sounds like it might be the fusible link.

1) How do I test the fusible link to see if that is the problem; is there anyway to bypass the fusible link to test it?

2) I have 69 parts car, but the fusible link looks different, is the 69 interchangeable with the 70?

3) Where can I get a replacement fusible link?

Thanks
Bob

[namba209]

Let's start with the path of trons from the battery. First there's the fuseable link at the starter. That can be checked with a VOM to check for continuity from the battery terminal to the other side of the fuseable link. If that's bad, most auto parts carry replacements. From the fuseable link the flow is to one of the four studs in the center of the fuse panel, across the buss bar to another stud, to the ammeter, from the ammeter, to the third stud, across that buss bar to the 4th stud, then to the alternator B wire. Any of those stud connections could cause the problem if the connections are not clean and tight. The next thing would be the chassis ground from the battery. Again, clean and tight connections are a must, including pulling the battery connections and make sure they are clean and tight. HTH.

[Lindsay]

New headlight wires from crimps near master cylinder to headlight connectors?
Remove headlight covers to inspect wires at headlight connectors.

Another easy way to test fusible link wires is to lightly tug on them. A blown link will stretch like a rubber band.

Catalog
There is always a four number size difference between the Fusible Link wire gauge size, and the size of wire going out to the rest of the circuit. The four number differences in gauge size will create the correctly calibrated bottleneck for the Fusible Link to function. Normal amounts of current flow through the Fusible Link do not generate enough heat to warm it up, and normal amount of current flow does not result with significant voltage drop. But in the event of a “full-overload” (“short-to-ground”) problem, excessive current flow through the Fusible Link (bottle-neck effect) will overheat the Fusible Link and burn it out. The protected circuit will be automatically disconnected from power.

I prefer pre-assembled fusible link wires with terminal rings already attached, rather than making my own connections. Know that NAPA auto parts has bulk fusible link wire. Need to ask in store, if you can not find.

[scodari]

Thanks for the information but I'm a bit confused. Can anyone shoot me a picture of the fusible link.....I'm not even sure where or what to look for?????

[namba209]

I can't help you with a pic, I took all mine out and replaced them and my fuses with circuit breakers. The fuseable link is attached to the same terminal as the battery cable on the starter solenoid. It is about 4"-6" long and is crimped to the 10 gage Red/White wire that goes in to the wire harness at the firewall. HTH.

[sawdust]

Originally Posted by scodari Thanks for the information but I'm a bit confused. Can anyone shoot me a picture of the fusible link.....I'm not even sure where or what to look for?????

It looks like a regular piece of wire. I got 20 feet of it if you need some.
You can get it at any parts store. size 14.

[Lindsay]

Catalog (For Picture)
See my post #3.

14 GA Fusible Link Wire crimped to:
10 GA Red w/ White at starter
10 GA Red at alternator

16 GA Fusible Link Wire crimped to:
12 GA Lt. Blue w/ White at voltage regulator

As I mentioned ... If fusible link wire melted inside, insulation will feel like a rubber band.

[scodari]

With my test light I check if I have power at the fuse box. I have at one of the 4 center lugs which has a red/white wire connected to it. That is the only lug that has power. None of the other fuse connections have power. It does not appear to be the fusible link. Do you agree? Any other ideas???

[namba209]

If you have power at the stud the Red/White wire goes to,then your fuesable link is o.k. and you should also have power to the stud that is outboard of it. Both are Red/White wires on the studs closest to the driver. You should also have power to the other two studs closest to the firewall and the spade lug to the right of those studs. Simply stated all 4 studs in the center of the fuse panel are hot all the time. Either directly from the battery or through the ammeter. If you don't have power at all four studs, then you have to check them for corrosion and tightness. They feed your whole electrical system, either from the battery or alternator.

[scodari]

I only have power to one stud - the one closest to the transmission tunnel and closest to the firewall. The other three studs have no power. If I run a jumper from the one hot stud to the one next to it (closest to the kickpanel and closest to the firewall); I get power to all accessories again. How do I fix this problem?

[namba209]

O.K. that doesn't make sense. The stud you have power on is the one that is fed from the ammeter. Which means there is power going from the battery/starter soleniod terminal through the two terminals closest to the driver, up to the ammeter and back. What you don't have is the power going/coming from the alternator. Unless the dreaded PO has done some innovative wiring changes. Under each stud is a copper strip connecting two studs side by side, together. It could be the wires attached to the studs are making electrical contact but the studs are not. I would remove the wires and nuts from each stud and thoroughly clean them and the copper strips so electrical contact can be assured. Also check to be sure there is a copper strip between each set of studs, it may be that one has been burned through. Troubleshooting trons long distance is not fun. It may be time to purchase a DESTEC wiring schematic, so you can see what is supposed to be happening.

[scodari]

Ron:
Thanks for the information. I did as you have suggested and removed some of the studs. Please take a look at the attached pics; let me know what you think.

What do I do now?

[namba209]

Well there is no doubt you had an extremely high resistance there to melt the plastic. I do believe the melting plastic insulated that one stud. You can try to remove the plastic from the copper strip, but it's 30+ years old and may break away. Best bet IMHO is to put a washer on the stud, so the washer makes contact with the copper strip and the stud, or you could just put in a heavy gage jumper between the two studs. Remember all the electrical power goes through those four studs. HTH.

It is interesting that you don't have power to the stud that is next to the one that is melted. That is supposed to be the battery connection from the starter solenoid. Could be the PO switched the wires on those two studs. It doesn't make any real difference though, if there is continuity between the two studs. In retrospect you could put both wires on the one stud, if you were so inclined.

[jvandyke]

Did you have things working before you did headlight work and then it went bad or it was not working for a while? I just ask because things melted down for a reason, probably should find out why BEFORE, if possible, otherwise other things may burn up.

[namba209]

That's a real good point. he said in his first post he was working on the headlights beore everything went south. I presumed it was for the wiring, but after reading it, he only fixed the rotating side of them. Might be a real good idea to check the wiring where it goes through the rotating mechanism. Or better yet, check the whole harness from the firewall forward. Many on the site have had wires burnt inside the grey sleeve in the engine compartment. I know it's a PIA, but better to be safe than sorry, later.

[Lindsay]

No GT wiring box and/ or fuse panel on eBay. Thought it would easier to replace fuse panel with a better condition used one. Are there less quantities of Opel GT parts on eBay the past few weeks?

[scodari]

Thanks all

Let me give you a bit more history. The PO had done a lot of electrical work on the car. The original ignition switch had been removed and replaced with a unit external to the steering column, but there was no key. To turn the headlights on and off, he installed a separate toggle switch, but the headlights didn't work. On top of those two problems, the headlight buckets would not lock open or closed, so I knew I had to do work on the swivel strips.

First we replaced the ignition switch with another one - also external to the sterring column and we were able to get the car started. I then proceeded to replace the toggle switch for the headlights and I got the headlights working with the new toggle switch. I wanted to make sure everything was working before I proceeded to remove the headlight bucket as I was cognizant of creating additional problems.

Once I was confident that all electrical systems were OK, I proceeded to remove the headlight bucket and replaced the swivel strips. I also cut the wires that came up through the rotating mechanism and installed a new 3-prong plug for the headligts and put two layers of shrink tubing. So I thought I was well protected. But obviously, I'm not.

I do have another fuse box still installed in my 69 parts car. Is the 69 fuse wiring and box the same as the 70? It looks like a PIA to swap; am I correct?

Thanks again

[namba209]

Actually the fuse block is removable from the power panel box. You have to have access to the inside of it. There's a plastic pin with spring clips on each end of the fuse block. I just tried to remove my old block from the panel and I could get one side loose with a thin screwdriver, pulling back on the spring clip, but the other side, I had to depress the clip from the inside. With the plastic being so old and brittle, extreme caution is needed. But to answer your question, the power panels should be interchangeable. It would take some time to swap over all the relays and connectors, but it can be done. The connectors can be removed with care and re-installed without taking out the individual wires. There is a locking tab on the top and bottom of the connectors. If you do change out either one, just be sure to tag all the wires.

[Lindsay]

Local (large) electronics store has (white?) shrink tubing with numbers marked on tubing. These would make identification of wire positions easier than using masking tape with marker. Maybe local Radio Shack or electronic supply store has wire identification markers? Hair dryer might shrink the heat shrink tubing instead of heat gun.

With all those electrical issues, I would definite order DESTEC GT Wiring Diagram. There are none on eBay now, but you can send DESTEC private email through this site or eBay.

Wiring diagrams at:
Opel Association of North America

[scodari]

Today I made up a strip of metal to fit inbetween all four lugs, see the first picture - this is before I re-attached any of the wires. I then proceeded to attach 3 of the 4 wires, see 2nd picture. I intentionally left the 4th wire disconnected as I believe that is where my short originated. With the three wires attached, I have all power back - all acessories work - headlights work and the car starts.

But I now have two additional problems:

#1 - The oil and amp light are on all the time. Whether the key is in or not. In fact, if I start the car, the car doesn't shut off when I remove the key. I had to pull the distributor wire to kill the engine.

#2 - I also wanted to see if I had a problem with the 4th wire, so I separatley ran a fused jumper from the 4th wire to the 4th lug, the fuse did not blow, so I don't appear to have a short (I think???) but, the amp gauge doesn't work either.

Suggestions are welcome regarding both problems!!!

[namba209]

I can understand the amp lite not working and the engine continuing to run. You bypassed the normal flow of power through the ammeter. Only the two forward and two rear studs are tied together. They're not supposed to be connected front to rear. With them connected all together, you have battery power to all the circuits all the time when the engine is running.

[scodari]

Thank Ron

I don't quite understand what I need to do to correct what I have done. Do you mean that I should revise the metal strip to only connect the wire coming from the battery/starter and the one going to the amp gauge????

[namba209]

Pretty much so. The Red/White wires go on the two front studs which are tied together with a buss bar, that's the copper strip between the two, and the Red wires go to the two rear studs, which are tied together with another buss bar that ties them together along with fuse #4. It may be easier to tie the studs together, electrically, with a short piece of heavy gage wire under the wire terminal ends. I noticed in your pics that you do have a blue fuse blown. It goes to the heater switch, cigarrette lighter, and headlight indicator microswitch in the left headlight bucket. HTH.

[scodari]

OK, I removed the metal strip that cross connected all four lugs and did as you suggested....put a short piece of heavy gage wire between the two lugs closest to the fire wall (see 1st picture). The results are pretty much the same....I have power, all the accessories seem to work but unfortunately, the amp light and the oil pressure light are on at all times, even if the key is not in the ignition switch and the ignition switch is not turned to the "on" position. (see 2nd picture). What do you think???

Thanks again

[namba209]

O.K. The power for all the gages and the two warning lites comes from fuse #6. Pull that fuse to see if the lites go out. If they do not go out, pull the Black connector at the rear of the power panel, not the steering column Black connector. If the lites still stay on, you have a breakdown in insulation from a power source to the Black/Red wire somewhere in the instrument panel harness. It could be either a Red or Red/White wire going to the ammeter. If the lites go out, then it's a power source from inside the power panel, again with an insulation breakdown with the Red/black wire and either of the two Red or Red/White wires. Both of the lites have a ground source that is not affected by the ignition key being on or off. Having the key on only supplies power to one side of the lites, the ground connection is broken and the lites go off by having either the alternator putting out a charge or oil pressure transmitter sensing an oil pressure buildup. This is the original wiring configuration, but may have been altered by the PO. HTH.