So I'm trying to install a new ignition switch I got from Rockauto for my 75 Dodge D100 when I get it in place and realize when I go to plug the connectors together that the wires on the new switch and the trucks wiring harness are two sets of colors.

I referred to my fsm and here are the trucks wires and what they do:
18G orange wire: starter relay
10G light blue wire: accessories
12G red wire: ignition run
14G pink wire: ignition starter
10G black wire: battery
18G blue w/white stripe: ground

These are the wires on new switch:
Light guage black wire
Heavy guage black wire
med guage brown wire
med guage yellow wire
heavy guage red wire
heavy guage blue wire

Should I wire these two together or try getting a different switch that are the right colors? This is suppose to be the correct switch for my truck according to Rockauto and the do both have the same number of wires. Thanks in advance for any replies I really need to get this thing back up and running soon! Sam

Do the plugs on the switch and the harness only fit together one way? Try plugging them together and see what happens. Otherwise, you are down to using a test light and figuring out what wires are hot in what positions of the switch and matching them to the wires on the truck that should be hot at those times.

The thick wires are going to be the power feeds, so one will be the main power feed from the battery, one will be the accessory power feed, and the other will be the main power return to the rest of the wiring harness.

Reed, when you line up the plugs in the correct position, all the guage thickness are correct between the two but all the wires are the wrong colors. Some do make sense for example, the thick red wire on the switch lines up with the thick black wire on the truck wich goes to the battery. The thin black wire from switch lines up with the thin blue wire from truck that is for the ground.

I guess I could plug them up and see what happens but Im afraid of frying something. If I connect the battery wires together to get power could I then test positions to check for juice on the other wires?

You could could make up a test jumper to provide power to the switch and then use a test light on the output wires from the switch to see what wires have power in what switch positions. Once you know what wires had power in the different positions, you can match up function and wire thicknesses to the known wiring on the truck, i.e. find the smaller gauge wire that is only powered when the switch is in the "START" position and match it to the wire that goes to the starter motor relay.

Ok, tested switch wires with a jumper and test light and everything matched up so I plugged them up and everything is good except I'm still losing spark in the transition from the start to run circuit. either starts and runs for ten minutes then dies OR will crank over with NO spark in start position then will fire and stumble (trying to start) as you turn the key back thru run position. This is why I was changing the switch. I've cleaned all the connections at the bulkhead connection and changed out ecm, vr, coil and wire, ballast, starter relay all to no avail!! Dont know where to go next.

Good that you checked and cleaned the contacts in the bulkhead connector. Sometimes those pins fail to lock in position and get pushed back into the housing.
Then what contact there is likely will be weak and/or intermittent. Check both sides of the bulkhead connector by pulling firmly on the wire to see if the contact is locked in place.

BC

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'64 Dart GT convertible, 64 Dart 170 2-door post sedan in faded blue and rust (the Az Dart) & a sixty THREE Dart 170 2-door post sedan in faded blue and rust. (future project)
Early Dart Disorder (EDD) is real, and I've got it!

Have you checked the pickup in the distributor?

All the connections at firewall are tight and appear to be good. I took my dremel with a small diameter brass brush wheel on low speed and carefully cleaned all the male ends until they were shining like new. Then I sprayed contact cleaner in the female ends and packed full of grease and reconnected. I did this on the whole bulkhead connector.

Reed, I did check distributor and pickup is still in correct adjustment. Its a DI special I have had for less than a year. When it starts and runs, Its as smooth as butter and revs strong.

Sunday night after I worked on it all day, it started and ran about 30 minutes, longer than the 10 min it usually does and dies. Then I noticed none of the accesories were working including the fuel guage so I started moving the ignition switch connector around and all the accesories came back and the engine would lose spark and miss just a little as I moved it around under the dash. So then I thought AHHH now weve found the problem! So then I go out on Monday afternoon to work on it and it starts right up (cold) like new on the first revolution wich is how it always has and runs about 10-15 minutes and shuts off again. When I tried to restart it was back to the same old crank then stumble and try to fire in the run side of the switch condition.

I did notice one side (half) of the dual ballast gets hot while idling. Is this normal? I thought the whole thing was suppose to get hot while idling. And the connector at the + side of the coil is old and frayed looking like not all the wire is connected, I'm going to put a new end on there and see what happens. I'm not experienced or very knowledgable with electrical so I'm really getting frustrated and dont know where to go next with this thing so any help I can get from you guys will be VERY appreciated!

You have a lose connection or broken wire somewhere. Check the heavy gage red and black feed wire’s soldered splices under dash, and tightness of amp gage connections.

Next time it quits carefully wiggle individual wires with just radio on & key in ACC position, and listen for radio to activate when bad connection is disturbed.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I agree this is no doubt the problem at this point. I havent checked those amp guage wires for tightness before but I will now. Where exactly are the soldered splices under dash you speak of?
This is a good idea, I will try that and see if this will help me pinpoint where the bad connection is. This weekend will be my first chance to work on it and I'll report back to you guys and let you know how it goes. Thanks alot for the replies! Sam

I havent checked those amp guage wires for tightness before but I will now. [quote]Where exactly are the soldered splices under dash you speak of?[/quote]

When pawing around under dash, be on the lookout for friction taped connections on red and black large gage wires. The splice is a “Yâ€￾ connection. You need to remove tape, inspect soldered connection, and make repair if necessary. Re tape connection using only #33 3M electrical tape, it won’t become stiff and unravel over time. If possible apply a second covering of electrical shrink wrap. Where this is 12 volt, dielectric properties of tape are not as important as the coverings ability to resist abrasion, and degradation from heating & cooling cycles an auto’s interior experiences over time.

You could also use friction tape as the factory did provided you can find some.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Last nite I found some time to work on the truck and noticed when I moved the 6 pin ignition switch connector around in my hand while the truck is running I would see a spark thru the opaq (clear) plastic in the connector. I observed this happening between both the run and accesories wire connections. The engine stumbles for a split second from losing spark as this happens. So I turned the truck off and wired the run wires directly together with male/female spade connector and the truck fired right back up but still shuts off after about 10-15 minutes of running.

When I checked wires with key in acc position the only time I could get radio to lose power was when I moved the accesories power wire at the connector. I've moved all the wires around on both sides of the firewall with it running and off and I get no loss in power except at that switch connection.I'm going to wire the accesories connection directly together next and see if it helps also. This old connector is obviously bad. I still dont understand why it is shutting off after 10-15 minutes of running though. Maybe I should chunk the connector and wire all the switch wires together. Is there any problem with doing that other than you wouldnt be able to quickly unplug?

I also checked the ammeter wires for tightness and they were good.

Moving or wiggling wires should have zero effect on electron flow; anything less is a repair waiting to happen.

Running ten minutes than shutting down indicates to me there is a component overheating and shorting out, or a loose connection activated by vibration.

Once engine self-kills, disconnect and [url=http://www.international-auto.com/fiat-lancia-electrical-system/how-to-test-an-ignition-coil.cfm]test coil[/url] with ohm meter while it is still hot, there is no test available to shade tree mechanic to test orange box except to swap out with known good unit.

Next is to trace and test neutral lockout circuit (if automatic equipped) including its switch, and “Runâ€￾ circuit through ballast connector, distributor, and coil to ground. Also be sure Voltage Regulator and Orange Box bases have good ground with zero voltage drop back to negative battery post.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Thanks Wjajr, I'll go buy an ohm meter and test the coil. I've never used one before, what should I look for in buying one? The VR is grounded to alternator bracket via 10 guage wire. The orange box I also ran a ground wire directly to battery negative with same Spark shutdown issue. One half of the dual ballast does get super hot while it is running I have noticed.

Test all circuits in the ignition chain when it stops (won't run!). See if there is power to the ballast resister and to the coil. If you have electronic ignition check power to the main feed. When my car behaved EXACTLY as yous is, the epoxy module on the distributor pick up was loose. It would run until the parts got hot, and then ghe gap would close. I found this only after pulling the distributor and inspecting things closely. A new pick up solved the problem. A year later and she is fine, but i still get nervous driving in traffic where it died on me a few times.

I have bi passed the ignition switch with a toggle for the ignition feed and a push button for the starter relay
God luck.

Sam

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