Electrical gremloins??

[Moriarty]

Thread necro!

put a jumper wire from the positive battery cable connection on the solenoid to the front left connection (on the front of the solenoid, farthest to the passenger side). It should crank. If it does, immediately go to the ignition switch and try and crank it. If it doesn't crank, then it's either the switch or the connections between the switch and the solenoid.

Situation:

• Starter works with jumper.
• Get nothing when turning the ignition switch.
• Radiator fan works when manually switched on, but lights do not.
• No voltage between the Brown and White wires at either the ignition switch or amp meter.

I'm not sure where to trace from here and could use some guidance.

Thanks!

[patrickt]

Originally Posted by Moriarty

I'm not sure where to trace from here and could use some guidance.

Thanks!

With the key off, check for voltage on all 16 screws on each side of the eight fuses that are on your firewall. Write down which screws have 12v and which don't. For example 1-Left and 1 Right might have voltage and 6-Left and 6-Right might not. If one side of the fuse has it and the other doesn't then the fuse is blown. This is the configuration of your fuses:

1L----1R 5L----5R
2L----2R 6L----6R
3L----3R 7L----7R
4L----4R 8L----8R

Post those results.

Then, turn the key on and repeat the process. Post those results. With that info we can tell you where to look.

[Moriarty]

Interesting.. new development.

With key off:
12.5----12.5 00.0----00.0
12.5----12.5 00.0----00.0
00.0----00.0 00.0----00.0
00.0----00.0 00.0----00.0

With key on (initially):
12.5----12.5 0.01----0.01
12.5----12.5 00.0----00.0
0.01----0.01 00.0----00.0
0.01----0.01 00.0----00.0

The ones I marked as 0.01 I happened to notice just barely flicker off 0 for a second as I was originally testing. I went back to them after writing down my findings to test with a lower voltage setting (more decimal places) and in the middle of this, they all (the ones marked 0.01 above) jumped to about 10.5V. At this point turning the key cranks the engine. However, after a couple tries it goes back into the "dead" state, but if I let it sit with the key on again, it eventually comes back.

Is this the circuit breaker maybe not liking the 30-40 degree weather we've been having recently?

Also tested the lights. They never come on, and if I flip the switch (even just the first notch for running lights) then the 0.01 screws all read 0.000 and never appears to fix itself as it does with the lights off and the key on. So that seems pretty suspicious.

[strictlypersonl]

Just for yucks, bypass the main circuit breaker (mounted next to the starter solenoid) by connecting both wires that are on separate terminals to the same terminal.

[patrickt]

Get on your back, with your head under the dash, your butt in the driver's seat, and your legs flipped over towards the back of the car. This is a picture of your ignition switch. With the key off, tell me which of the four terminals, A through D, have 12 volts. Then turn the key on and repeat the process and tell me which of the four have 12 volts. Post your results here.

[patrickt]

And an easy way to temporarily bypass the big circuit breaker and the amp gauge is to just run a jumper wire from the big positive side of the starter solenoid to the left screw of the #1 fuse.

[66gtk]

Originally Posted by patrickt

Get on your back, with your head under the dash, your butt in the driver's seat, and your legs flipped over towards the back of the car.

Like this?

[patrickt]

Originally Posted by 66gtk

Like this?

Yep, and that's when a quick release hub is worth its weight in gold.

[Moriarty]

Okay. When in a state where turning the key will crank:

A has 12v w/ key off.

A, B & C all have 12V w/ key on.

As soon as I flip up the light toggle, they all go dead.

(I assume D would have 12V as well when cranking, but did not have enough hands to test that.)

[strictlypersonl]

Check for corrosion at the passenger's side of fuse 1 and 2. That is the common connection of the ignition switch and the lights.

[patrickt]

If cleaning the terminals for corrosion doesn't fix it, then we'll try something more. But first a couple of questions, 1) Is your ignition switch wired the same as mine with the same colors at the same terminals? 2) Do you have a traditional points/condenser ignition or an electronic ignition, like MSD. If you happen to have a MSD ignition, and it's under the dash above the passenger's feet, take a quick look under there and tell me if you have a big MSD capacitor next to your MSD box. Then, jumper a temporarily bypass wire from the big positive side of the starter solenoid to the left screw of the #1 fuse. Assuming it doesn't immediately heat up and start smoking, check to see if your lights now work. If they do, see if the car will now fire up and what now works and what now doesn't.

[Moriarty]

Cleaned terminals for good measure, but was getting voltage to both sides before, so I don't think that was a problem.

1) Ignition wiring:

• B terminal I have two brown wires (instead of one brown one yellow).
• C is white.
• D is red, but also has a black cable (for MSD?)
• A is yellow rather than green.

ERA build #412 if that matters.

2) MSD 6AL - installed on the X bar near the radiator. Do not see any capacitors around.

jumper a temporarily bypass wire from the big positive side of the starter solenoid to the left screw of the #1 fuse. Assuming it doesn't immediately heat up and start smoking, check to see if your lights now work.

No smoke - I put a 30A fuse inline on the jumper just in case.

No lights. No change in behavior - can crank but goes dead when lights are toggled on.

Thanks for all the direction so far btw!

[patrickt]

Strange. Let me ask this question: Is this a new electrical problem? Has the car ever, to your knowledge, run just right with all the electrical components working as they should? What I'm trying to figure out is whether this car was goofily wired to begin with, or whether it was wired properly and something bizarre is occurring.

[patrickt]

In looking at the wiring diagram for your particular car, and since you have 12v at fuse #1 with the key off, you should have 12v at the BATT terminal with the key off, which is B on my picture, but you don't. One of the two brown wires on terminal B goes straight to fuse #1 and the other brown wire goes straight to your light switch. Try pulling fuses 6, 7, and 8 and leave them out. Then see if the car will start normally and behave normally, electrically, except for the fact that you have no lights. If it starts and runs, then try turning the light switch on and off, hit the hi-beam switch, and see if anything dies, etc. If everything seems ok, put fuse 6 in and repeat, if that's ok, put in fuse 7 and repeat, and if that's ok, put in fuse 8 and repeat. It shouldn't survive that test and I'm mostly interested in which step kills it.

[Moriarty]

It had been running fine, and I had been using the lights without issue.

It was only the other day that I went to take it out and when it didn't start on the first crank, discovered that it was dead on the second attempt. I initially assumed the battery was dead since I hadn't started it for a week or two and didn't remember to hook up the trickle charger. It was only after the problem persisted the next day after charging that I realized something more was going on.

There have been a couple instances in the fairly recent past where I've turned the key and gotten nothing, but then a second turn and things worked fine.

At this point, it seems like I must have a short in the lights wiring which is triggering the circuit breaker?

It's mostly just the weather getting colder that has changed.

I hadn't checked the heater all this time, so I just did that now. It works the same as the radiator fan - i.e. no problems, light toggle doesn't affect it, does not require key.

I also double checked the brake lights and turn signals work, but all go dead when the lights are toggled.

While testing, everything started working fine at one point. I was testing to see if the radiator or heater fans cut out when turning the headlights on. I first turned on the radiator fan, then turned on the lights and they worked and everything else worked. I thought maybe it had fixed itself, but after toggling the lights on and off about five times, the problem returned.

When I first encountered this issue, I crawled up under the dash to check connections and didn't find anything loose - though I don't really know what to look for beyond that.

[patrickt]

Alright, try the fuse 6, 7, and 8 test....

[Moriarty]

you should have 12v at the BATT terminal with the key off, which is B on my picture, but you don't

Oops, I reported that wrong. I was thinking A was the top terminal when testing. Yes, the brown wire(s) at the top of the ignition switch has 12V when the key is off (the others do not). Sorry about that.

Try pulling fuses 6, 7, and 8 and leave them out. Then see if the car will start normally and behave normally, electrically, except for the fact that you have no lights. If it starts and runs, then try turning the light switch on and off, hit the hi-beam switch, and see if anything dies, etc. If everything seems ok, put fuse 6 in and repeat, if that's ok, put in fuse 7 and repeat, and if that's ok, put in fuse 8 and repeat. It shouldn't survive that test and I'm mostly interested in which step kills it.

Okay, this time I noticed a sound coming from the boot when turning on the lights. I think it's probably the accusump cutting out, but couldn't be sure.

Pulled fuses and problem went away as predicted. Installing #6 makes it return.

[patrickt]

OK, that's progress. Leave Fuse 6 on the table and see if you can put fuse 7 in then fuse 8, then both fuse 7 and 8.

[Moriarty]

I can kill it with any one of the three fuses in place on their own it seems.

With #6 in place, if I disconnect the lines at all of the four parking lights, then the issue goes away. Maybe that's obvious.

[Moriarty]

And fuses all seem to be wired as expected fyi:

#6 - kills with parking lights
#7 - kills with high beams
#8 - kills with headlights