C.V.R. or Light Switch

[bird 60]

Hi Guys, We were out for a joyride with the Club out in the country. We stopped for a meal & after a couple of hours it was time to go. When we took off everything was O.K. It was starting to get dark so I put the lights on & the Engine died. I switched the Lights off & started the Car, but when I switched the Lights on again the Engine died again. The Fuel gauge not working & no Instrument lights. I started the Bird again & only turned on the Parking lights & it was O.K. We were about 25 Miles from home & arrived without a problem. Luckily I didn't get picked up by the cops. The next day I drove the Bird around the block a few times with the Headlights on & didn't conk out. The Fuel gauge still not working & no Dash lights. We had a Car Show last week & was dark when we left & had the same problem after about three minutes of starting the Bird. Luckily the Show was only about 1 1/2 miles from home. I drove home with the Parker lights again.
Can someone please advise.

Thank You

Chris......From OZ.

[jopizz]

Obviously putting the lights on is causing some sort of voltage drop to the coil. Is your generator light coming on? Since the CVR operates regardless of whether the lights are on or not I don't think that's your problem. The first thing I would do is put a voltmeter on the coil and check the voltage with the key on. Then see what it is with the headlights on. If there's little or no change then try it with the engine running. If it's something with the headlight switch or circuit I suspect it shouldn't matter if the engine is running or not. You should see a significant voltage drop. Before I changed out anything I would check the battery, battery cables and the ground connections to the block and firewall.

John

[bird 60]

Hi John, & thank you for your reply. All cables seem to be tight.

Coil reading with ignition on.......4.87
""""""""""""" with lights on..........4.66
""""""""""""" with engine running lights on 3.07
""""""""""""" with engine running lights off 3.43

Checked 3 times with some fluctuation.

Thank you.....Chris

[bird 60]

I forgot to mention, I have an Alternator & the light was NOT coming on with the engine running & the lights on, only when the ignition was turned on. Battery fully charged 13.7.

Chris.

[jopizz]

You should have from 6 to 9 volts at the coil. You have a pink resistance wire that lowers the voltage from 12v. I would check the main yellow wire that goes from the solenoid to the headlight switch and over to the ignition switch. If you are getting 12V at the ignition switch then it's possible the resistance wire between the ignition switch and coil is bad.

John

[Yadkin]

I agree with John on the resistance wire, or possibly a connection in that circuit, is bad. Since the pink wire is buried in the harness, not an easy job to replace. You should consider upgrading to a Pertronix Ignitor module to replace your points along with their matching coil. These run on 12 volts, not the 6 that an OEM set runs on, so you can just run a new wire from your ignition switch and abandon that pink resistor wire altogether.

[Tbird1044]

I fully agree with the upgrade to the electronic ignition if not already done. You have never stated if you are still running the points or not. Does the problem primarily occur after things get hot? I have seen ign. coils fail and short out when they get hot. Your voltage already appears low at the coil. You may disconnect at the coil and see what the voltage readings are with the wires disconnected.
Nyles

[scumdog]

Has any though gone into why the dash lights now no longer work? Likewise the fuel gauge?

[simplyconnected]

Hmmmmm... Turn lights on and the CVR and ignition goes dead...

Your resistor wire may be ok.

John mentioned the yellow wire that comes from the battery side of your starter solenoid. BE CAREFUL This wire is not fused (so disconnect the battery before working on the headlight or key switches). It terminates at your headlight switch with a post and nut connection. A very short yellow jumper then feeds the ignition switch at another post and nut. I suspect this jumper is loose because multiple devices are affected on your key switch.

Your saving grace is the points! If you had an electronic ignition it would NOT work. Points and your ignition system will still function at very low voltage. The engine will get erratic before voltage becomes too low to fire plugs. - Dave

[bird 60]

I had the ignition switch replaced nearly 10 years ago with a new yellow wire, & a fuse before the starter solenoid. I've got the Pertronix distributor, also an Alternator but the Coil looks standard.

Chris

[jopizz]

I believe with the Pertronix distributor you should remove the resistance wire so the coil gets the full 12V. You can usually use your stock coil as long as it's around 1.5 ohms.

John

[simplyconnected]

I had the ignition switch replaced nearly 10 years ago with a new yellow wire, & a fuse before the starter solenoid. I've got the Pertronix distributor, also an Alternator but the Coil looks standard.

Chris

Again, I'm with John. Solid state components need full voltage.

Chris, I'm not suggesting your yellow wire is bad, I'm suggesting it has somehow worked itself loose. I believe a bad connection, probably at the headlight switch, is the reason your engine shuts off when you turn the lights on. The solenoid fuse in the starting circuit is not stock but ok. Ford did not fuse your ignition circuit. Exactly where in the circuit is this fuse? - Dave

[bird 60]

Thank you for your advise Guys. As I'm not overly clued up on the electrical side of things I'll get my electrical man to do some tests.
Thank you once again.

Chris......From OZ.

[bird 60]

Hi Dave, the Fuse is between the Alternator & the Starter solenoid.

Chris.

[Tbird6]

Replace the headlight switch.
.
.
.