Electrical problems with #782
 

Bob - I tried to send a PM on the issues below but it looks like it's not getting sent as it's not showing up in my sent items. Anyway, here it is in case my PM didn't get through.

I energized the electrical system in #782 for the first time today and I have a number of issues. Here are a few qualifiers in case they may be contributing:

- I unplugged my ballast resister to protect my distributor points from burning while I was testing.

- Brake system isn't filled with fluid.

- License plate light is not installed.

Problems I found are:

1. With battery hooked up but key off - the ignition light is on and the tail and parking lights are on. There is a slgiht discharge showing on the amp gage.

2. No turn signals

3. Heater runs full time with key in accessory or ignition position. I switched the leads on the switch without any change. I suspect the switch is bad.

4. No brake lights (possibly because the master cylinder doesn't have any fluid in it?)

5. Headlights, horn, wipers, dash lights and engine fan all seem OK. I didn't try spinning the starter since I had these other problems.

6. the right front park light would not light up at first. It had power to it but there isn't a ground in the harness for the housing. The black wire in the harness turns and runs to the headlight run and back up to the engine compartment. I ran a ground from the housing to the left light housing and it lit up. I don't know if that will interfer with the turn signals or not - I don't think so???

I double checks the wiring on the ignition switch and starter relay and everything is OK according to the manual and wiring diagram. I was careful wiring everything up. The ignition light/parking lights on with the key off is the issue of most concern immediately.

Thanks in advance for your help.

Dan

Jeez, it's almost impossible to wire the starter relay wrong, and only slightly less impossible to miswire the ignition switch. But, wtf, nothing's fool-proof, so here are pics of mine. Are yours wired like this?

http://www.clubcobra.com/photopost/data/500/elec001.jpg

http://www.clubcobra.com/photopost/data/500/elec002.jpg

Dan ... the heater switch on mine is doing what yours is . Looks like Lucas strikes again . Probably a defective switch . I was able to move mine around until I found a sweet spot where the fan cut off ... but if I hit a good bump , it comes back on . On my Winter list to replace .
Yes , for your brake lights to come on , you need hydraulic pressure on the switch to activate it ... i.e. master cylinder filled and system bled .
Electrical gremlins can be a bear to track down and not one of my favorite things to do .... and I was a EE in a previous life .
Have fun??

Yes - my connections match yours and the manuals. It couldn't be something that easy.

Bobcat - I suspected that on the brake lights - wasn't 100% sure.

I'm hoping Bob recognizes some sign of a previouly made error that would send power to the ignition light and parking lights with the key off. Otherwise I guess I'll have to pull everything back out and trace every circuit through every connector and connection.

What I Would Do...
 

Remove the wires from your ignition switch. If the ignition & parking lights still stay on, you have a mis-wire elsewhere; backtrack the circuit to find the origin of the feed. If the lights go out, measure the continuity across the poles of the ignition switch to confirm it is indeed a bad switch. A faulty ignition switch is not uncommon.

I can try removing the wires from the ignition switch. I need to double check the connections on the light switch too, although I doubt something crossed there would cause the ignition light to come on also. I suspect there is something in common with the two.

As was said before, check the connections at the ignition switch. Also the connections at the head/park switch.

Could be many things, including low voltage. Let's get the rest of the stuff out of the way first.

Probably

The switch is hydraulic. No pressure, no electricity.

Something weird here. I don't ever remember ever sharing the parking light ground with the headlight ground. Just not the way I build the harnesses. Both grounds end up connected at the crossmember connection. But a separate wire will work

The headlight switch is powered whether the ignition is on or off, so there's something awry at/with the light switch. The other possibility may be a couple of wires switched at one of the multi-pin connectors. I'll have to dive into that possibility this morning. You might check yours yourself: The wire colors on each side must match. Any wires with stripes are at the corner of the plug to make them easier to identify.

OK. I'll work on these ideas and contact John about a new heater toggle switch.

I'll double check the leads in the harness connector the lights run through and at the light switch.

The harness for the parking lights looks definately incorrect. There's nothing on the harness to ground to the light housing. I remember wondering about that when I installed the harness a couple months ago - fiberglass cars need a ground for virtually everything. I guess I could splice into the black wire that loops through the wheel well from parking light leads to headlight leads and connect it to the housing for ground - but if the separate ground from left to right won't impact turn signals I'll leave it as is.

Dan, I have 781 and I had headlight troubles too. Hit a bump, lights on, hit a bump, lights off. A friend of mine pulled over to see what I wanted and why I was signaling him. Turned out to be a bad switch on the dash, and I had to replace it a few times. Just a bad batch that got out there. JUst a thought as our #'s are so close.

I pulled the battery and starter solenoid leads off of the ignition switch and connected the battery. The ignition light was out now but the tail/park lights still came on. If the light switch always has power I doubt this means anything.

I played around with the light switch and there isn't any difference between the off (down) posiiton and the parking lights (middle) position. I did notice the lights blinking off as I moved the switch from off to parking position. I tried to look at the wire connections with a mirror and as best I could determine they are as shown in the wiring manual. I wired up the dash while it sat on a counter and took my time studying the manual. I'm 99.9% sure everything is wired correctly.

I think the light switch is bad.

I don't know why the ignition light is lit up while the switch is off but maybe it's getting power backfed to it from the lights. Any thoughts on that?

Does anyone have a source for the correct socket for unscrewing the nut on the toggle switches? Mine are on real tight. I tried my usual shade tree tricks of C-clip pliers and tapping on a small screwdriver lodged at an angle in one of the slots with a hammer - without sucess.

Thanks

Power to the light switch is independent of the connections to the ignition switch.

That would seem to confirm a bad switch.

Is your fuel gauge working with the ignition disconnected? The power for the warning light comes from the same circuit. If the gauge doesn't have power, power is being fed back in the opposite direction, from the voltage regulator. Check the connections at the V-R plug and at the alternator.

Moss Motors

I'm not sure about the fuel gage. It's reading empty and I haven't put any gas in it yet. I'll see if I'm getting power to it.

Thanks

I seem to have everything up and working now that I can tell - except the pass side turn signals are still not blinking. Filled the car up with antifreeze today and had a big leak at the thermostat. So no start for the first time today.

For working with the nuts on the toggle switches, I saw a post somewhere with someone suggesting that you grind down a deepwell socket, leaving just the two tabs, to make a wrench. I believe he suggested a 9/16 socket, but I'm not sure. I plan to make one for the next time I need to change a switch since I think it will be cheaper than the Moss Motors tools.

An old drawing of the required tool:
http://www.erareplicas.com/427man/wiring/bezel_tool.pdf

I borrowed one from one of the Forum merchants that is built out of 1 inch pipe, maybe rigid conduit - not sure. For what Moss Motors get for them, I think he could tool up for a hundred of them and sell them here on the forum.