Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
A couple of days ago I took advantage of the unseasonable cool weather and went for a drive. At one point the overdrive stopped working. The fuel gauge as well as the turn signals also stopped working, but the car kept running fine. I got home and let it idle for a few minutes. While at idle the fuel gauge and turn signals still were not working and windscreen wipers didn't work, but the headlights were working. I turned it off and a few minutes later I inserted the key and turned it on. Zilch, zero, totally dead. I know nothing about electricity, but I suspect a short. I would appreciate advice on how to approch this problem and where to start the search and what is the likely source.
-
Hi Guest!
You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
my trusted 100-4 Healey died.
- Thread starter Arch 93
- Start date
Share this page
pan
Jedi Warrior
Offline
The first problem would seem to be the fuse. The O/D works through the same fuse as the other functions listed.
The latter problem indicates a greater problem but shouldn't be too hard to trace. Start at the beginning with the batteries. Then check the all cables, between the batteries, to the isolator switch, and under the car to the starter solenoid.
The latter problem indicates a greater problem but shouldn't be too hard to trace. Start at the beginning with the batteries. Then check the all cables, between the batteries, to the isolator switch, and under the car to the starter solenoid.
Offline
Thomas,
I'm going to go with your knowing nothing about electricity. I suggest you get an inexpensive multimeter and learn a bit about how to use it. You will wonder how you got by without one. You can check the state of your batteries and the cables to the starter by going to the starter solenoid in the engine compartment. It is a small can shaped item, and if you find the cable from the starter motor (which is on the right side of the motor way at the back and down low) you will see a heavy cable that is short and goes to the solenoid. If you reach your hand to the back side of the solenoid you will feel a rubber boot. This is a manual starter button that you can press. Leave the ignition off (the engine may crank, but won't start then) and keep your neck tie and anything else away from the fan and pulleys. If you press this firmly and the engine cranks, you have battery juice and good cables. If you get nothing, let us know and the other suggestions will start flowing. It almost sounds as if you have had a generator or voltage regulator failure except that your headlights were working. Let us know what happens.
Jon
I'm going to go with your knowing nothing about electricity. I suggest you get an inexpensive multimeter and learn a bit about how to use it. You will wonder how you got by without one. You can check the state of your batteries and the cables to the starter by going to the starter solenoid in the engine compartment. It is a small can shaped item, and if you find the cable from the starter motor (which is on the right side of the motor way at the back and down low) you will see a heavy cable that is short and goes to the solenoid. If you reach your hand to the back side of the solenoid you will feel a rubber boot. This is a manual starter button that you can press. Leave the ignition off (the engine may crank, but won't start then) and keep your neck tie and anything else away from the fan and pulleys. If you press this firmly and the engine cranks, you have battery juice and good cables. If you get nothing, let us know and the other suggestions will start flowing. It almost sounds as if you have had a generator or voltage regulator failure except that your headlights were working. Let us know what happens.
Jon
BIBBER
Jedi Knight
Offline
make sure your really putting out a charge...not sure if the 100-4 is like my early Sprite but everything draws off the battery if it's not charging eventually DEATHe....I learned on my first night time outing years ago...first the small items, then the motor finally just quit but I still had a little headlight until thst went dead as well..GOOD LUCK!
Offline
Hi Tom,
All of your problems are associated with the lower fuse block position. This fuse should be 35 amp Lucas or 20 amp USA rated. You DID say the head lights are still working?
The unfused side of the fuse block should have four white wires connected.
The fused side of the fuse block should have four green wires connected.
The stop, turn, fuel, & wipers are fed from the green, FUSED wires. The OD is fed from a white, UNFUSED wire. The white wires side of the fuse block is fed from the ignition switch.
The ignition switch is fed by a brown/blue wire which comes from the lighting switch common terminal.
Since the circuits on both sides of the fuse including the ignition?, now seem to be having trouble, I would suspect that the brown/blue wire between the lighting switch & the ignition switch is not making a connection. Or, the ignition switch itself. All of the circuits mentioned originate from the ignition switch "ON" terminal.
If I'm wrong & the ignition is still working, the problem is likely the white wire between the ignition coil & the fuse block.
I would start by checking/cleaning the fuse block connections & the fuse clip contacts & go from there. If the lighting doesn't work either, check the battery cut off switch in the boot & the battery.
D
I attached a partial wiring diagram if it will help.
D
All of your problems are associated with the lower fuse block position. This fuse should be 35 amp Lucas or 20 amp USA rated. You DID say the head lights are still working?
The unfused side of the fuse block should have four white wires connected.
The fused side of the fuse block should have four green wires connected.
The stop, turn, fuel, & wipers are fed from the green, FUSED wires. The OD is fed from a white, UNFUSED wire. The white wires side of the fuse block is fed from the ignition switch.
The ignition switch is fed by a brown/blue wire which comes from the lighting switch common terminal.
Since the circuits on both sides of the fuse including the ignition?, now seem to be having trouble, I would suspect that the brown/blue wire between the lighting switch & the ignition switch is not making a connection. Or, the ignition switch itself. All of the circuits mentioned originate from the ignition switch "ON" terminal.
If I'm wrong & the ignition is still working, the problem is likely the white wire between the ignition coil & the fuse block.
I would start by checking/cleaning the fuse block connections & the fuse clip contacts & go from there. If the lighting doesn't work either, check the battery cut off switch in the boot & the battery.
D
I attached a partial wiring diagram if it will help.
D
Attachments
Keoke
Great Pumpkin
Offline
Well Dave, one could remove both the 35 amp fuse and the 50 amp fuse and the Headlight circuit or the ignition circuit could care less. From the failure description I would think that the generator ,Control Box or the fuel pump were at fault. It follows that the battery may be defective or discharged--Fwiw--Keoke
Offline
Hi Keoke,
The original description is a bit mysterious. If it is correct, first, the OD was intermittent. Then the fuel & turn, but ignition was ok. Next, wipers, fuel, & turn were out, HL worked. Later, everything dead?
The only thing common to all would be the battery disconnect switch or battery connection or failure. But from the description, things failed sequentially.
If the battery was going down, I would be surprised that the headlights still worked.
The old regulators had a compensating winding between "A" & "A1" which was intended to boost the regulator setting when loads were applied. The only thing connected to to the uncompensated terminal was the horn. If this winding failed, the horn would be the only thing left working.
Probably something simple, but you know how these remote diagnosis things go. Hope Tom gets it worked out.
D
The original description is a bit mysterious. If it is correct, first, the OD was intermittent. Then the fuel & turn, but ignition was ok. Next, wipers, fuel, & turn were out, HL worked. Later, everything dead?
The only thing common to all would be the battery disconnect switch or battery connection or failure. But from the description, things failed sequentially.
If the battery was going down, I would be surprised that the headlights still worked.
The old regulators had a compensating winding between "A" & "A1" which was intended to boost the regulator setting when loads were applied. The only thing connected to to the uncompensated terminal was the horn. If this winding failed, the horn would be the only thing left working.
Probably something simple, but you know how these remote diagnosis things go. Hope Tom gets it worked out.
D
Thanks for all your input folks. I haven't had a chance to get at this yet, but tomorrow morning I'm going to give it a go. Dave, I studied the wiring diagram and it appears that the horn is on a 50 amp fuse by itself. Of course the horn is the one thing I didn't try to see if it worked. It looks like the OD and fuel pump are not fused, but that doesn't seem right. However they are grouped togeather, which I'm thinking means that they would both stop working or both continue working, but that doesn't figure because when the OD went out the fuel pump kept working since the engine kept running????????? If you don't mind, could you enlighten me on what the little circles labeled A1, A2, A3 are?
Again, thanks.
Again, thanks.
Offline
Hi Tom,Thomas Speer said:
The drawing is a schematic wiring diagram. All wire connections are shown by lines & terminals. They do not necessarily represent the actual wire path but only it's connection points.
As Keoke said, the circles are wire terminal connections. A1, A2, A3, A4 are the fuse block terminal numbers. I didn't number the terminals on the other devices. It is a very abbreviated portion of the complete wiring.
The lighting switch connects the Brn/Blu wire to the red wire when it is in the park position & additionally connects the Blu wire in the HL on position.
The ignition switch connects the Brn/Blu wire to the White wires when it is in the On position.
The white wires at fuse terminal A3 are not fused. The Grn wires are all fused from fuse terminal #A4.
The OD & fuel pump are not fused. Each is supplied by a SEPARATE white wire from the fuse block terminal A3.
Note that fuse terminals A1 & A2 are physically located at the top fuse of the fuse block.
As I said earlier, the failure sequence that you describe is not consistent with any one single problem, except maybe a low battery, the battery disconnect switch, or the voltage regulator internal connection from A to A1.
If the horn still works, the battery, the battery disconnect switch, & the Brn wire from the VR to battery are intact. (Make sure that the 50 amp fuse is good) You could rule out the VR internal connection being bad if jumpering VR terminals A & A1 makes no improvement.
The battery voltage from fuse terminal A1 to ground should be around 12.5 volts to diagnose wiring problems.
I know it's new & frustrating, but hang in there, you'll figure it out.
D
Offline
Some folks add fuses to the OD circuit, the fuel pump circuit, & the tail light circuit. The tail light circuit (license plate lamp) is very vulnerable to damage from a slight rear end bump.
D
D
Hi Dave and everbody:
Well things are getting more bizarre. I went out this AM to deal with this issue, or at least do as much damage as I could. Turned on the ignition and the fuel pump started clicking and the needle on the fuel gauge immediately went to 1/2 full. Horn, lights, etc. all working. It fired up and I took it out for a drive and the OD worked fine. I wasn't hallucinating when this all started and I don't drink; well maybe a scotch or two in the evening.
The battery, fuses and cut off switch are obviously O.K. I should add that a couple of years ago I had a fair amount of work done on the car including a rebuilt generator, new coil and other electrical items including a new cut off switch. As to why it healed itself, I have no clue. I'm hoping that you who are more knowledgable than I have some insight into this. My uneducated theory is that there is a short in a wire(s).One point I'm a little confused on; is the OD and fuel pump fused or not? I thought they were?
Again, thanks for your time and knowledge.
Tom
Well things are getting more bizarre. I went out this AM to deal with this issue, or at least do as much damage as I could. Turned on the ignition and the fuel pump started clicking and the needle on the fuel gauge immediately went to 1/2 full. Horn, lights, etc. all working. It fired up and I took it out for a drive and the OD worked fine. I wasn't hallucinating when this all started and I don't drink; well maybe a scotch or two in the evening.
The battery, fuses and cut off switch are obviously O.K. I should add that a couple of years ago I had a fair amount of work done on the car including a rebuilt generator, new coil and other electrical items including a new cut off switch. As to why it healed itself, I have no clue. I'm hoping that you who are more knowledgable than I have some insight into this. My uneducated theory is that there is a short in a wire(s).One point I'm a little confused on; is the OD and fuel pump fused or not? I thought they were?
Again, thanks for your time and knowledge.
Tom
Offline
Keoke -- Me too.
Tom,
There are four separate white wires on fuse block terminal (A3) -- the unfused side. The first goes directly to the fuel pump. the second comes directly from the ignition coil, which is connected to the source feed from the ignition switch. The third wire goes to the OD relay terminal (C1). The fourth wire goes to the OD dash switch.
On the BN2, a clean way to add fuses to the OD & fuel pump is to add a second fuse block just below the original. See attached drawing.
D
Tom,
There are four separate white wires on fuse block terminal (A3) -- the unfused side. The first goes directly to the fuel pump. the second comes directly from the ignition coil, which is connected to the source feed from the ignition switch. The third wire goes to the OD relay terminal (C1). The fourth wire goes to the OD dash switch.
On the BN2, a clean way to add fuses to the OD & fuel pump is to add a second fuse block just below the original. See attached drawing.
D
Attachments
Offline
My TR4 exhibited somewhat similar symptoms at many years ago, in my case corrosion on the solenoid cables was intermittently cutting out power when restance was too great or voltage too low, would come and go mysteriously.
If the whole car weren't quitting I would have guessed dirty fuse box connections.
I would clean off the solenoid cables, battery cables, and the little clips that contact the fuses, this and hopefully the problem goes away for good or at least a good long while.
Greg Lemon
54 BN1
If the whole car weren't quitting I would have guessed dirty fuse box connections.
I would clean off the solenoid cables, battery cables, and the little clips that contact the fuses, this and hopefully the problem goes away for good or at least a good long while.
Greg Lemon
54 BN1