Lights and fuses issues

Bill Francis · 02-03-2011, 09:35 AM

Thanks to the member's responses I have my fog lights restored and operating, albeit with a funky switch attached to the bottom of the dash. (The push/pull switch I got from SierraMadre that they said would fit my "68 912 was rectangular instead of round and would not fit through the substructure hole in back of the dash which is also round.) I tried to make it fit and fatally damaged the switch in the process.

Now I'm troubleshooting some light/fuse issues.

1. With the ignition off and the doors shut, I am seeing live voltage (using a test light) on numbers 2, 3 and 4 fuses. Are any of these supposed to be live with everything off?

2. The hazard lights only work on the right side.

3. The license plate lights and luggage compartment lights work briefly before blowing a fuse.

Any help to resolve these issues will be appreciated.
Bill

Jaems · 02-03-2011, 01:38 PM

Yes, there is a wire direct from the battery that goes to 3 and 2, 4 are also connected.

You need to get a wiring diagram for you car.

You also need to clean all your grounds and check the bulbs and fuses.

You have a short in one of the hot wires from fuse 6. That is probably why you are blowing fuses.

Bill Francis · 02-03-2011, 04:37 PM

Thanks Jaems, I have done some more searching here and learning a lot. I cleaned all the fuse recepticals and retightened the screws that hold the wires. Will keep trying and keep you posted.
Bill

Jerry1 · Jerry1's Garage

Hi Bill
Here is the web site to a great wire diagram

http://www.hillmanimages.com/912/early_912_wiring.pdf

These diagrams are very accurate I hope this helps you keep us posted.

Bill Francis · 02-04-2011, 03:15 PM

Thanks Jerry, I took Jaems advice and had the wiring chart in my owner's manual enlarged to 20"x 30" and laminated at Walmart. It came out great. There are some symbols that I haven't figured out yet but most are readable. I am going to try to trace my number 6 fuse short tomorrow. I found instructions for making a cheapo short finder using a 20amp circuit breaker which I am going to try tomorrow.

On the fuel guage problem, I pulled the sensor from the gas tank with the cylinder that drops into the gas tank but everything looked clean and upon reassembling it the guage still reads 0.

Well, one thing at a time.
Bill

Jaems · 02-04-2011, 04:14 PM

Bill,

When you took the sender apart was the two copper wires still in tack? Did the sensor slide up and down the copper wires with no problem? Sometimes there is a little corrosion on the copper wires that will keep the sensor from moving very easy. This can happen if the tank is not full when stored for long periods of time. Just take your two finger nails and slide them gently up and down the copper wires will remove it. If the wires are in tack, the sensor side very easy up and down the the two wires. Then most likely the sender is OK. Usually it is one of the copper wires that break that causes the problems.

Then check the three wires by cleaning the contact points for the ground (br), the reserve tank(bl), and the sender wire (gr). Then check the wires for breaks and they are hooked up correctly.

Bill Francis · 02-05-2011, 04:20 AM

Jaems,
I did not see any copper wires, just a cylinder with a nut and bolt on the bottom. Are the wires supposed to be on the inside of the cylinder?
Bill

Scott Douglas · Scott Douglas's Garage

Bill
Take a closer look at the schematic on Dave Hillman's site. There's a file there that will allow you to pick the circuit you want to work on and it highlights only that circuit in the schematic. Very cool feature if you ask me.

Jaems · 02-05-2011, 10:30 AM

You have to take the nut off of the bottom and slide the cylinder off. Then you will see the copper wires (about the size of hair) and the sensor. Some have fix the wires if broken. Most of the time it is just corrosion on the wires. Be very carefully in scraping off the corrosion with the finger nails. You don't want to break the wires. Your not out anything if this doesn't work. Except maybe a $100 for a new sender.

I would check the wires first and make sure that they are OK. Just in case that is the problem.

Bill Francis · 02-05-2011, 10:47 AM

OK, I will do that. Have been trying to find why the left side of my hazzard lights don't work. Both sides of the turn signals work and the hazzard lights operate off the same bulbs don't they? I pulled out the driver's side floor board again to expose the relay and flasher. There are two wires (both brown I think) going down through the deck. There is a small access door underneath the deck which I assume will give me access to those wires so I can check the ground. If that is not the problem I'll have to look elsewhere.
Bill

Bill Francis · 02-05-2011, 01:41 PM

Jaems, I removed the nut and ceramic cap from the sensor cylinder and the three wires appear to be intact but the sensor is fastened somehow to the bottom of the cylinder so that I can't pull it out to clean the wires. Is it merely stuck to the bottom with corrosion after 42 years? Should I try to pull it out with brute force? What would you suggest?
Bill

Jaems · 07:08 PM

There should be a cap that goes over the top of the cylinder. The tiny nut at the bottom of the cylinder that hold the cylinder to the top by a shaft that has the threads on the end for the nut. The center of the sensor slides up and down this shaft making contact with the two copper wires The wires and the shaft are the whole length of the cylinder. After the nut is removed the cylinder should slide off. It is only there to protect the two wires and the sensor. If it is that tight. You might try gently turning the cylinder to break it loose. Then it should slide off. Also check and make sure that the washer under the nut also came off. It has been about 15 to 20 years since I took one apart. However, it is rather simple.

Bill Francis · 02-06-2011, 03:51 AM

OK, I think we are on the same page. Starting with the cylinder in its normal position in the gas tank, the bottom of the cylinder has the nut and bent up washer on it. The top has the electrical connector connected to it. There is nothing that I can see under the connector to hold the shaft. The bottom of the cylinder has a orange (phenolic?) cap which I removed. So now it is a matter of loosening and removing the wire assembly from the cylinder.
Bill

Jaems · 02-06-2011, 10:02 AM

The wires and the shaft are connected to the top piece and stay that way. Just the long cylinder will slide off. I never worried how the shaft was connected to the top piece. My only concern was that the wires were still connected, not broken, and the sensor slide freely up and down the shaft and the wires. If it is that hard to take apart. The sender is probably not any good anyway.

I don't have any pictures to show you what to look for and I am not going to take mine apart to show you. The 911 crowd may have some.

Bill Francis · 02-06-2011, 02:39 PM

Success! I put a little WD40 down the tube and let it set awhile and it came right off. I cleaned the wires with fine emory cloth and put it back together and installed it in the tank. The gauge still doesn't work. Bummer!
I did find the short in number 6 fuse route and now the luggage light and the license plate lights now work.
The hazzard lights on the driver's side are still not working. Was unable to remove the access panel underneath the floor to check the ground wires.
Thanks again Jaems for all your help!
Bill

Bill Francis · 02-06-2011, 04:32 PM

I found the short by using the procedure described by 6Nheat at

Tech consisting of two lengths of 18 gauge insulated wire, two alegator clips, a 20 amp breaker and a compase. It worked. The short was in the luggage compartment fixture, apparently one of the connections had grounded to the boot metal.
Bill