If anyone has a hard starting '74-'78 C Body read this...

[stilbo]

I feel bad that my Dad put up with hard starting until he passed at 92 years old in 2007... Especially when the fix was so cheap and easy.
Chrysler made a small change to the starter relays in their RWD cars in '78 &'79.
They added a fourth terminal to put full battery voltage directly to the coil.
The first photo is the early relay and the second is the 1978 and on relay.
You can find them on Ebay for less than $15.00.
Search for starter relays used on any 1978 and later Chrysler RWD vehicle.
After 41 years of nearly wearing out starters, my '74 Sport Suburban 400 starts about as easily as my wife's 2012 Honda Accord...

 

[1978 NYB]

Thanks....nice tip.

 

[commando1]

Thank you. I will remember that.
I am still a little confused about the rewiring tho.

 

[1978 NYB]

No rewiring for either of my cars...

 

[commando1]

Well if going from 4 terminal to 5 terminal, aren't we going to come up short in the wiring dept?

 

[1978 NYB]

Well if going from 4 terminal to 5 terminal, aren't we going to come up short in the wiring dept?

Yes.....on your 76. No on either of my 78's.

 

[1978 NYB]

BTW, I unplug the solenoid plug (brown 2 plug connector) on it as my redneck disable the car and it won't crank. I also unplug one of the dual terminal's on the ballast resistor as a back up disable. Someone would have to be very knowledgeable Chrysler thief to steal either of my cars....

 

[stilbo]

I love that redneck disabling system.

 

[1978 NYB]

I love that redneck disabling system.

Most people can't even tell.....LOL! I leave the connector resting real close and it appears to be hooked up.

 

[stilbo]

FYI:
If you compare the early and late relays you'll notice that the fourth terminal is the one right next to the threaded lug. That's the terminal you run a heat resistant 14 gauge wire from and to the coil + terminal.
You'll need to replace the ring lug on the wire that went to the small screw terminal with a female blade connector. I soldered mine onto the wire rather than crimp in order to minimize resistance.
The early design doesn't supply enough voltage during cranking due to voltage drop associated with the starter's draw down.
If you have a hard starting pre '78, you won't believe the difference.

 

[twostick]

I'm confused. Mopars have always bypassed the ballast resistor when the key is in the start position. That's why when the ballast is shot, it will start but quits as soon as you let go of the key.

Kevin

 

[1978 NYB]

Mine start really easy. Of course no Lean Burn on my 78's any more and I have Eddie 1406's on them. Starts in 3 seconds and 727 is ready to go immediately....even if I let it sit for a month.

 

[1978 NYB]

BTW, I drive my 78 NYB from Baltimore to Green Bay and back twice a year. Very dependable road car. I would drive it anywhere anytime....

 

[commando1]

Welcome 1978NYB... Nice house!

 

[1978 NYB]

That's a random house on Lake Shore Drive in Milwaukee.......LOL!

 

[Yatzee]

I hate to be the bearer of bad news but if the car had a ballast resistor, there was always full voltage to the coil in the "start" position. It's after it started and you let the key come back to the "run" position that the coil voltage dropped slightly. Your's may may be the exception and not the rule. I suspect there was an issue with the start relay to begin with or there's another gremlin lurking in the shadows.

 

[stilbo]

To the best of my knowledge the coil does experience a voltage drop as the current path is through the ignition switch circuit.
I measured the + terminal voltage on the Fury and the Road Runner with and without the conversion and they average 2.6 volts lower.
Both cars deficient?
1978 and up cars have the fourth terminal...

 

[Big_John]

It seems to me that this bypasses the ignition switch/dash wiring/bulkhead connector etc.

I think it's a very good mod.... The only issue is you have to remember that you can now start the car at the relay. Not good if you are just bumping the starter when doing something like adjusting valves. It won't stay running... but we all have heard the stories of guys putting their car through the back wall of the garage.

 

[78Brougham]

I don't have to worry about anyone stealing my cars where I live.... keys are right in the ignition or the ashtray! But beware of the 1911 and my neighbors!

 

[stilbo]

John...
Did a full trans service Saturday...
Had to bump the solenoid to index the torque converter plug to six o'clock.
While under the car.
Thank god it didn't start.
I woulda freaked.
Any other time I work on it with the quick disconnect terminal open on the battery.
And yes, the mod bypasses everything you mentioned.
That's why Chrysler engineers changed the design in '78.