US88 Ignition switch - Starter stays running

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Harry J Scribner

Harry J Scribner

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Hello. I recently picked up a '74 Dart. Tracked down an electrical problem (Someone re-routed the hot wire to the column because it looks like it shorted with no fuse and melted the connector in half, etc.) The source of the problem was the ignition switch, the crimping on the plastic cap failed and the 3 springs inside looked like they'd been in a blender. Took it apart got a couple springs from the hardware store, put it all back together. Lasted a handful of drives, came apart again. Picked up a Standard Ignition PN: US88. It fits poorly, the arm is a bit longer than the original so it wont seat all the way into the key mechanism, however it works. The RED wire isn't pictured but it's connected to the battery.

The problem is, the key ON position runs the starter non stop and the START position shuts it off. The car starts and runs. If I swap the BLACK (ON/ACC) and YELLOW (START) wires at the connector it should fix it?

Any insight is greatly appreciated.

I read through a few threads and didn't see my exact issue, apologies if it's there and I missed it.

Thanks!

dart new.jpg
dart old.jpg
 
Swap black and yellow? Uh no................

I would pull the yellow loose at the starter relay. Then troubleshoot "in safety." With prior harness "meltage" you might have something crossed/ welded in the harness. Or it might just simply be a defective switch, which has been reported by others, or since I'm not there it may fit so poorly that is causing the thing to trigger the yellow

OR MAYBE someone improperly rewired it

ON THAT NOTE check and perform the bypass on your seat belt interlock. The yellow start wire is interrupted on the road to the starter relay by the interlock device. This is a box about the size of a horn relay over on the inner fender some place with a push button (used to be red) reset. You will find two "yellowish" wires. You need to permanently splice those together.
 
67Dart273 said:
Swap black and yellow? Uh no................

I would pull the yellow loose at the starter relay. Then troubleshoot "in safety." With prior harness "meltage" you might have something crossed/ welded in the harness. Or it might just simply be a defective switch, which has been reported by others, or since I'm not there it may fit so poorly that is causing the thing to trigger the yellow

OR MAYBE someone improperly rewired it

ON THAT NOTE check and perform the bypass on your seat belt interlock. The yellow start wire is interrupted on the road to the starter relay by the interlock device. This is a box about the size of a horn relay over on the inner fender some place with a push button (used to be red) reset. You will find two "yellowish" wires. You need to permanently splice those together.
Click to expand...

Thanks for the info. I'm pretty familiar with the wiring now and troubleshooting it. Had to hotwire the car to see if it even ran. Seems the seatbelt interlock has already been bypassed (Thanks for noting what that box with the button is).

The car operated correctly before the ignition switch came apart, again.

The wiring colors are matched to the factory wiring.

Just realized I can cycle the switch outside the column to prove/disprove that fit is the issue.
 
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No idea your electrical experience. Be careful checking the switch, say, with resistance. I prefer to do this with power, under load. If no other load, sometimes I "rig" an old stop/tail lamp or headlamp to provide a test load.

Resistance can throw you astray. Modern high impedance digital meters can sometimes show continuity when there is actually a high resistance, and any power present can lead you wrong or in some cases damage a meter

There has been threads where the column switch contacts can "float around" in the switch. Maybe it's just defective
 
switch.jpg
67Dart273 said:
No idea your electrical experience. Be careful checking the switch, say, with resistance. I prefer to do this with power, under load. If no other load, sometimes I "rig" an old stop/tail lamp or headlamp to provide a test load.

Resistance can throw you astray. Modern high impedance digital meters can sometimes show continuity when there is actually a high resistance, and any power present can lead you wrong or in some cases damage a meter

There has been threads where the column switch contacts can "float around" in the switch. Maybe it's just defective
Click to expand...

The contact plate in the switch was floating around when I originally opened up the column.

I use a fluke multimeter in 12VDC mode, or a 12V mac tools automotive test light when looking for power. If it's continuity I use whatever the "beep" mode is on the multimeter.

The issue is related to the -new- switch itself. It's the part number listed for my car but there is a note in the box explaining how to wire it for different year vehicles. It seems that none of the notes that came in the box require alternate wiring of the main wires. The switch is sending constant and momentary power to the wrong places. I'll map out the function of each wire with the test light and see what I get.
 
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It’s not the fit. Cycled the switch outside the column. Same results. Constant power to the yellow wire. Compared the new and old switch, totally different wire locations on the back. Went to Napa. The switch they have also doesn’t match the factory switch. Any idea where to look for a switch? Nothing I’ve found online matches.
 
I sure don't know. Parts stores are not "what they were" Frankly if you have all the pieces I'd consider trying to repair the old one?
 
This reminds me of a brand new Ford Ranger delivered to the dealership. Heat a/c blower ran on lower speeds but no air flow from any vent. Switch to blower high would blow a fuse. I found every wire in a 8 port harness connector in reversed positions. I think you are the victim of a temp worker on assembly line also, except your fault is where the wires are placed in the switch not the connector. Try another switch, from NAPA or maybe a different part store.
 
RedFish said:
This reminds me of a brand new Ford Ranger delivered to the dealership. Heat a/c blower ran on lower speeds but no air flow from any vent. Switch to blower high would blow a fuse. I found every wire in a 8 port harness connector in reversed positions. I think you are the victim of a temp worker on assembly line also, except your fault is where the wires are placed in the switch not the connector. Try another switch, from NAPA or maybe a different part store.
Click to expand...

NAPA showed they had the correct switch. Went there and matched up the OEM switch, all the wires were in different locations on the switch body just like the replacement I already have installed. Rather than going through the $$ and wasted time again, I drilled a hole next to the cigarette lighter and installed a push button for the starter. Works great. Also, the wires at the switch body had some terminated with a swage and solder and some just swaged so I soldered the rest.
 
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Switch worked for a week. Now it has hit or miss power to the ignition so the car sometimes starts. I can't find a cross reference, or any reference to the number on the switch itself other than an eBay item. Is there another year/model switch that fits this column? PN on the switch is: 3488573
 
Since you've been chasing electrical gremlins I have to ask, have you downloaded a FSM & check the wiring per the diagram. I ask because I've seen no reference to that.
 
Demonracer said:
Since you've been chasing electrical gremlins I have to ask, have you downloaded a FSM & check the wiring per the diagram. I ask because I've seen no reference to that.
Click to expand...

Yes, and it all makes sense. If I put direct power to the wires that require it, everything works as it should, the car starts and runs.

The wiring on the back of the replacement switch doesn't match the original.

The replacement switch doesn't interface smoothly with the key cylinder.

Is this a part there are no direct replacements for? Should I roll the dice on a used one? I have a local parts guy checking who is really good at figuring out crosses and tracking parts down. Hopefully he'll come up with something.
 
One thing you might do--and maybe even "should" whether you go used/ new is rewire the thing so the key triggers a relay for the IGN1 buss, and maybe the ACC buss as well.
 
67Dart273 said:
One thing you might do--and maybe even "should" whether you go used/ new is rewire the thing so the key triggers a relay for the IGN1 buss, and maybe the ACC buss as well.
Click to expand...
That makes sense since this switch did at least activate the IGN, and now it's intermittent failing.

I re-checked a couple more places online, they have the Standard Ignition US88 and some other brand. Rolling the dice on the other brand. Wont be here till next week.
 
The US88 is a universal switch, if I were you I would put a "Wanted ad" on this site for a good used one & correct the burnt wiring problem with the flat connector on post #1.
 
Demonracer said:
The US88 is a universal switch, if I were you I would put a "Wanted ad" on this site for a good used one & correct the burnt wiring problem with the flat connector on post #1.
Click to expand...

The burnt flat connector was part of the old IGN switch, so it's gone.

I'm going to try swapping in the new switch (different brand) that's coming, and if it works I'll install the new dash pad and likely trade the car off for something else.
 
Harry J Scribner said:
Yes, and it all makes sense. If I put direct power to the wires that require it, everything works as it should, the car starts and runs.

The wiring on the back of the replacement switch doesn't match the original.

The replacement switch doesn't interface smoothly with the key cylinder.

Is this a part there are no direct replacements for? Should I roll the dice on a used one? I have a local parts guy checking who is really good at figuring out crosses and tracking parts down. Hopefully he'll come up with something.
Click to expand...

It's not going to either. THe internals of the switches are different from the OEM switches. I recently went thru this myself.

You'll have to map out the circuit and pin it out so that it lines up with the dash side of the harness.

It took me a few days of internet reading and reading thru the FSM i have to wrap my head around it too.
 
shanker said:
It's not going to either. THe internals of the switches are different from the OEM switches. I recently went thru this myself.

You'll have to map out the circuit and pin it out so that it lines up with the dash side of the harness.

It took me a few days of internet reading and reading thru the FSM i have to wrap my head around it too.
Click to expand...

Thanks! I found a thread on here that was sort of related to this, something about wiring in an MSD box etc. The post included figuring out which contacts internal to the switch are bridged to initialize starter, ign etc. I just received a switch from an alternate manufacturer to the the Standard Ignition brand switch. Comparing it to the OEM switch the contact positions still don't match. The good news is the actuating arm looks to be the same length as the OEM switch, where as the the Standard Ign brand switch had a slightly longer arm making the engagement feel shitty when you turn the ign key. It works like I have it wired up now with a push button in the ashtray for the starter. Side issue: Some mornings power drops to the IGN circuit. Once it starts up and runs it won't do it again all day. Only the first start of the day. I can tell when it happens because the oil (?) light on the dash is off with the key switched to the on position, if the oil light is lit the IGN is hot.

At this point I'm going to install this new switch that appears to have the right length arm, so the engagement should be proper. Then map out which wires should be connected according to their function, and add relays for the starter and ign circuits.
 
I would map things out before you install it. Here is the basics, you can make a "truth table"

POWER IN. This was originally a large gauge wire, varied in color.

ACC out. This connects to POWER in both ACC and "RUN"

IGN1 "run"..This connects to POWER in "RUN" I would guess also shows continuity to ACC in "RUN" IGN1 is hot ONLY in run, and goes dead in START

IGN2 and START. These are separate contacts and should not show continuity to each other in "OFF" or "RUN" or "ACC" Both these should connect to POWER when twisted to "START" IGN2 feeds power to ignition system in "START" and it's purpose was to provide "full battery" power to ignition and to bypass the ballast resistor in START

START was yellow for most years, IGN2 was brown.
EDIT....The IGN2 goes one place...out through bulkhead to coil+ side of ballast
The START wire only went one place as well--out through the bulkhead, to the starter relay

Since you have a 74, make sure the yellow wires at the seat belt relay interlock/ reset--out on the fender apron under the hood--make sure that you splice the two yellows permanently together to disable that interlock. Also don't forget that start relay will not engage without a ground at the second terminal of the relay coil.......the transmission neutral switch with auto, or the clutch switch with a stick
 
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67Dart273 said:
I would map things out before you install it. Here is the basics, you can make a "truth table"

POWER IN. This was originally a large gauge wire, varied in color.

ACC out. This connects to POWER in both ACC and "RUN"

IGN1 "run"..This connects to POWER in "RUN" I would guess also shows continuity to ACC in "RUN" IGN1 is hot ONLY in run, and goes dead in START

IGN2 and START. These are separate contacts and should not show continuity to each other in "OFF" or "RUN" or "ACC" Both these should connect to POWER when twisted to "START" IGN2 feeds power to ignition system in "START" and it's purpose was to provide "full battery" power to ignition and to bypass the ballast resistor in START

START was yellow for most years, IGN2 was brown.

The START wire only went one place as well--out through the bulkhead, to the starter relay

Since you have a 74, make sure the yellow wires at the seat belt relay interlock/ reset--out on the fender apron under the hood--make sure that you splice the two yellows permanently together to disable that interlock. Also don't forget that start relay will not engage without a ground at the second terminal of the relay coil.......the transmission neutral switch with auto, or the clutch switch with a stick
Click to expand...

Thanks! Hoping this weekend to find time to swap it out and see if I can do a better job melting connectors than the last guy that worked on it.
 
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