Topic: 40 Mercury Cowl Wiring (Part II)


rradar    -- 10-09-2011 @ 1:06 PM
  Started the final hookup of the cowl loom but the ignition switch diagram is up side down and so the placement of the 3 wires that go on it is a question. The diagram shows coil and gage terminals at the top and battery terminal at the bottom. On my switch it is reversed. There is 1 terminal at the top and 2 on the bottom looking up from the floor.

Is there a way to be sure the wires are correctly placed??

Thanks, Radar










TomO    -- 10-10-2011 @ 7:39 AM
  The battery lead (yellow and black wire) goes to the terminal marked BATT or the common point on the switch.

The coil lead (black and red wire) goes on the terminal marked COIL.

The gauge lead (black and green wire) and accessories are attached to the terminal marked GAUGE.

The wiring diagram that you have is the same one that was published in 1940. The ignition switch was changed, but the drawing was not.

Tom


rradar    -- 10-10-2011 @ 8:53 PM
  Thanks, Tom

Apparently I missed the those little words on the ignition block. Will look and see what I can find. May have to get my helper to check also. Will give it a try tomorrow. Hopefully we can finish up the job then.

Radar


rradar    -- 10-28-2011 @ 10:57 AM
  Update on cowl wiring project. My helper looked and found no words on the ignition block. So we just hooked up the 3 wires anyway. Then, we connected the battery cable and pushed the starter button and the motor fired up right away. So, guess we just lucked out. There is just one problem now, the lights don't work. Since I have no testing light, I'm not sure how to trace back to the power into the light switch. Looking at the wiring diagram, it would look to have power coming into the circuit breaker and then up to the light switch. Is there quick way to see why my lights are not working?
Thanks, Again, Radar


TomO    -- 10-29-2011 @ 7:29 AM
  Radar,

Looking at the back of the ignition switch, the Batt terminal is the top one, the coil term is on the right and the gauge terminal is on the left. You can transpose the gauge and coil terminal wires, but you may lose some reliability. The coil terminal has a larger contact surface for the brush than the gauge terminal.

I would suggest that you go to Radio Shack and buy an analog (the one with the needle) voltmeter. Buy the one with the largest face that you can afford. You will find this tool very useful for trouble shooting electrical problems. The meter is more useful than a test light and the purchase price is not that much more.

Your parking lights and tail lights are powered directly from the dash switch. If they work, your wiring to the switch is correct. If they do not work check the yellow and red wire from the circuit breaker is going to the Yellow/Red wire on the switch. Make sure that the wire from the circuit breaker is pushed fin the bullet connector far enogh to make good contact.

If they work, check the wiring to the dimmer switch and the dimmer switch itself. You will need a voltmeter to check this out. Measure the voltage going into the switch at the Yellow/Black wire and the output at each of the other terminals.

Tom


rradar    -- 10-29-2011 @ 4:36 PM
  Thanks Tom,

It was helpful to have your input. Will need to get that volt meter so that I can follow up on your suggestions. The Mercury is a very original car. It is a pleasure to own it and I am looking forward getting it out on the road to enjoy driving it. Will post again when I've found out what is causing the lighting problem.

Radar


rradar    -- 11-05-2011 @ 1:33 PM
  Located a tester that has a voltmeter function. Had helper get under dash and check connections. Found that the circuit breaker had an open circuit. (Power to one side but not the other) So concluded that the circuit breaker is defective. Ordering this item turned out to be more challenging than the search for the lighting problem. It seems that there are plenty of circuit breakers for 41-48 model Ford and Mercurys but not for the 1940 models. Did locate one in Salem, Oregon and ordered it. The project is now on hold until the circuit breaker arrives.

Radar


TomO    -- 11-07-2011 @ 9:17 AM
  Thanks for the update.

Tom


rradar    -- 11-12-2011 @ 4:26 PM
  OK, here is the latest from under the Mercury dashboard. The circuit breaker arrived and we tested it to be sure that was functioning. Just hooked a lightwire up to one terminal and touched the other terminal to a battery connection. The light went on so we thought the CB was good. Now here is the puzzle. We took the old CB out and did the same thing with it. It functioned just like the replacement CB. So, looks like we don't need to replace the CB. But can't figure out where the power is lost from the new loom to the lights. Could the light switch be bad or some connection not right?? My helper (my wife) has lost faith we will ever get this wiring right. Since she has to get under the dash, she rules the underdash world for the moment!! More about this when we recover from our neck pains!!

Radar


TomO    -- 11-14-2011 @ 9:48 AM
  Rradar, does the dome light work? Do the stop lights work? If these all work, the CB is good.

Do the parking lights and tail lights work when the light switch is pulled out to the first position? If they do, you have voltage to the switch. If not, then check all of the bullet connectors going to the light switch, paying special attention to the yellow and red wire.

Do the tail lights work when the switch is pulled all of the way out? if they do then check the wiring at the dimmer switch or the dimmer switch itself.


Tom


rradar    -- 11-15-2011 @ 3:44 PM
  Thanks Tom,
Will have to suspend this project for a warmer day. Planning to go ahead and install the replacement CB and just try your ideas. What puzzles me is the CB I took out seemed to be OK. But, will have to have someone who is electrical test it for sure.

Radar


TomO    -- 11-16-2011 @ 7:14 AM
  Just come back with the solution or more questions when you are ready.

Tom


rradar    -- 11-28-2011 @ 8:38 PM
  The weather warmed up and we came back to the underdash wiring project!! Installed the CB supplied by a parts dealer here in Oregon. But just hooked it up without mounting it to the firewall in case it didn't work. Well, fortunately, when we got it together and connected the battery everything worked!!! So we mounted the CB to the firewall and it still worked. So now we have lights!! Have a few auxiliary wires to hook up and this project will be done!!! Thanks again Tom for your helpful advice and encouragement--it is great to know there are some good V8-er folks who will come through when you need them. Will now take the 40 Mercury out for a test drive and see if everything still checks out.

Radar


TomO    -- 11-29-2011 @ 9:16 AM
  Enjoy your ride, thanks for the update.

Tom


EFV-8 Club Forum : https://www.earlyfordv8.org/forum
Topic: https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=16&Topic=3832