74 Dart Elec issues with Instrument Cluster Starting - Perplexed

[Sonny's Darts]

I have a 1974 Dodge Dart Swinger Slant Six. My grandfather bought it new and when my grandmother passed away back in 2004 it became mine. It had sat for years, in a garage and only had 52k miles on it. After towing it from Ohio to Missouri a and few weeks of rehab had it up and going passing the safety inspection with flying colors. Did all work myself, keeping it as original as possible.
Last year I replaced the starter relay and ceramic ballast. I had trouble starting.
Recently, part of my wiper linkage had broken, I had a water leak coming through the dash since I have had the car (never drive in rain, only when washing car) and my dash lights in my instrument cluster all seemed to burn out at once (not the high beam, nor oil light). The gauges all worked fine.
I pulled the instrument cluster, replaced the voltage limit regulator on the cluster printed circuit. I notice all the lamp sockets had one of the tabs broken and thought that was one reason the lamps didn’t work, so I replace the bulbs and socket with new ones. I repaired the wipers and found exactly where the leak was. I was on seventh heaven. Or so I thought.
When I got it all back together, the wipers worked and the lights in the cluster seemed to work – it was daytime so I couldn’t tell if they all worked. Went to crank it up and nothing. First thought was the old seat belt interlock system. Pushing the by pass switch in the engine compartment didn’t work. Tried various combinations of unplugging the connectors under the seat didn’t work either.
After a couple weeks and buying the body and chassis manual ( I had my old 68 manual from my mom’s car –my first car, and chiltons, I thought I needed the actual service manual for the 74) and working on it a few nights after work I had thought I had thoroughly checked all the instrument cluster connections and did everything I thought I could. Check the fusible link –it was fine, also.
Finally I decided I needed to bypass everything and put my 14 year old son in the driver seat, explained how to put foot on brake and crank it over while I took the screw driver to the starter. It cranked right up!
After it warmed up, turned it off, and it started up fine a few times. We checked a few more things and we decided to take it out for a test drive. After about a mile, my son said something about the gauges moving. I noticed I had a full tank of gas, minutes later only ¼ tank, I am sure it was more or less full from my drive a couple months ago. My alternator was showing discharge and it is usually fluctuates a little based on lights on and giving it gas but mostly near dead center – it was only about a ¼ from the left side. . I didn’t drive enough to for the car to fully warm – it runs a on the cool side of the temperature range. I didn’t want to burn anything out, so we headed home.
I expected the brake light indicator to work, since I replaced all the bulbs, could not be the light but switching mechanics. Alternator and gas gauges worked fine before replacing instrument cluster voltage limit regulate and lamps. And I had such trouble trying to get it to start before the screw driver trick.
I have new voltage regular, but haven’t put it on –I decided to stop putting new parts on and see if I can isolate the problem, but can’t.
Anyone have any ideas what to check – I don’t think it is the seat beat interlock, its pretty much disconnected. Car started several times after using the screw driver on the starter with ignition. With gauges acting up I think it is something electronic – on of my many weak areas of expertise. B
Sorry to be long winded.

 

[67Dart273]

I have to tell you that all that was a little difficult to follow

It appears that

It won't start using the key

Some of the lights in the cluster do not work

The charging system has failed.

(Please correct)

Unfortunately, I don't have access to a 74 shop manual. If you have a CD version, we'd all appreciate it if you'd contact ABodyJoe here and make arrangements to upload it. Newest manual I know of to download is the '72

Here's the basis for how the seat belt relay generally works in conjunction with the start relay.

Older cars with no seat belt interlock had a 3 terminal start relay (stick) or 4 terminal (automatic). Newer stick cars with a clutch safety switch ALSO used the same "auto" style 4 terminal start relay.

So on the 4 terminal start relay, the coil of the relay is the two "push on" terminals. One comes directly from the ignition switch through the bulkhead to one push on terminal of your start relay. (Does not matter which one

The second "push on" terminal sees a ground in park or neutral, or on stick cars, you must depress the clutch.

One cars WITH the seat belt interlock, the contacts of the interlock relay are added IN SERIES with the wire coming from the key. IF you have this (big relay with push button) just disconnect the two "yellowish" wires from the relay and connect them together.

Otherwise, make sure you have a ground on the neutral safety switch (or clutch switch) for the other side of the relay

To check this, have a helper twist the key to "start" on command. Probe the yellow wires at the interlock relay to confirm that you get power in "crank."

Then move to the start relay, determine that you have power there "in crank."

The remaining "push on" start relay terminal should NOT show power in "crank." If it does, it indicates that the neutral safety or clutch safety is NOT closed

(Be careful with the following that the car is OUT of gear!!)

You can use a clip lead to ground on the NSS switch connection at the start relay to help confirm this.

Don't discount that the start relay just might be bad

To determine if the start relay is good/ bad, disconnect both "push on" terminals, ground either with your clip lead, and then short from the "big stud" on the relay to the remaining "push on" terminal

The relay should operate and engage the starter.


Charging:

Couple of quick tests. Take a meter or test lamp and turn the key to run. Find the BLUE wire at the alternator field. (There are two "push on" connectors, one blue, one green) Without unhooking anything, probe the blue connection and see if there is battery power

Next, pull the connector off at the regulator, and probe both connector terminals BOTH should show battery voltage.

If this looks OK, Replace the connector.

Go back down to the alternator, and unhook the green wire, use a clip lead and hook the exposed alternator terminal to ground.

Start the engine and slowly bring up RPM. The alternator should charge on the ammeter.

IF not, you either have a bad alternator, or wiring problems in the car.

If it DOES show a charge, hook the green wire back up, unhook the blue and ground that terminal. Unhook the regulator connector once more, and short around the two terminals in the connector

Once again, run the engine, and see if it charges.

IF so, replace the regulator. If not, you have a broken wire in the field circuit.

Many of these cars, now that they are 40 years old are developing wiring problems. One big troublemaker is the bulkhead connector

Please read this article on the subject:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Post back here with results, and we'll try'n help ya

 

[Sonny's Darts]

Well, long story short, I back traced my steps, ensured seatbelt interlock connectsion undone, make sure all connections to cluster were made and it fired right up. The gauges all work, brake indicator light still doesn't work and the same cluster lights that didn't work before still don't. So, I'm back where I started, except I know where my window leak is at and my wiper linkage works.

It actually starts right up better than before. I'm wondering it that was a short somewhere between the ignition and starter relay. I did lower the steering column for access to under the dash and notice a couple wires pinched. I straighted them out.

I appreciate the help. I need to learn up on electronics and circuit testing.

 

[wjajr]

Brake indicator light only comes on when an imbalance in line pressure is sensed. This happens when either front or rear brakes fail. Some models will illuminate the brake indicator when parking brake is applied by a switch mounted somewhere on or adjacent to the parking brake lever under the dash. If your car is so equipped, that switch may need adjustment.