How to Repair or Future Proof your Valiant Starter Relay

My S series Valiant was in for some body repairs. When I arrived to pick it up it wouldn’t start. The spray painter panel beater asked, do you have a special starting secret? No, I replied. I tried, nothing. He called his friend an Auto electrician who arrived with a test light and set about fault finding under the bonnet. After a short while he thumped the starter solenoid and asked me to turn the key. Bingo it worked.

I didn’t turn the car off on the way home and drove steadily home. I found a replacement relay and called Ken Spurling and asked if he would help me fit it. Better than that he said I can fix your old one!

I took the car round to Kens and we began the repair. The primary problem with the original starter solenoid is that the electrical terminals are riveted. Over time these corrode and loosen and therefore lose good electrical continuity and connection.

The starter relay is located on the right side of the firewall as you face the car.

Photo of the unit in situ ready for installation.

Remove the unit from the firewall.

Open the pressed over crimps on the underside of the body and remove the cover.

Your solenoid should look something like the shot on the right side.

Strip into bits and clean using either a small hand wire brush or a small wire brush in an electric drill wearing appropriate eye protection.

The piece in the bottom of the pic below is one side of the points

With all the electrical joints cleaned and using a reasonably beefy soldering iron solder the electrical joints inside and out as below……

The finished item ready to be put back into the body and push the crimped fingers over to retain it.

Assembly back onto the firewall and connect up according to your wiring photo and turn the key.

Note: If you haven’t had trouble with your starter solenoid and haven’t repaired it, it may be a good to consider the above repair.

I asked Ken Spurling if he has some further comments ….

The following is rather a thorough restoration service of the Park/Neutral Start Relay. If on the other hand this is too daunting for you, then at least clean and solder over the rivets of the top two (relay coil) terminals without any further disassembly being required, this just might be enough to get serviceable again.

I’ve repaired about six of these relays now, I had this same trouble back in 1998 in Albury, NSW when I attended the Chryslers on Murray Spotlighting the QRS Series Valiants. The fault occurred in Albury when I cleaned the car for the Show. Driving all the way from Perth to Albury I encountered many road works and the engine got covered in dust. To clean the engine quickly I begrudgingly decided to lightly hose it down as others were waiting to use the hose to clean their cars, of course I wet the neutral start relay causing a little more corrosion to the riveted terminals. If you look at the top picture ‘relay in situ’ on the firewall, notice the top two terminals rusty rivets securing the quick connect tabs to the insulated material, these corroded riveted joints make for a resistive weak connection to the coil that pulls in the relay to close the switch contacts to energise the starter motor solenoid.

It's been many years since our cars were built and oxygen has crept into the abutted metal surfaces of the relay causing a slightly higher resistance between the riveted together metals, enough to cause spasmodic malfunction of the relay. Sometimes the relay can be coaxed into operation by tapping the side of the relay or by gently grasping together all the wires connected to the relay (I learnt this from Dave Barnes President of the Queensland Club), this puts side pressure on the terminals enough to change or lower the resistance within the rivetted joints to make a sufficient circuit to work. But of course, this is unreliable. Fitting a modern type of relay is going to need other modifications to cater for the heavy positive terminal bolt connections, i.e. it is much better to retain the original relay and service it.

The relay can be serviced reasonably well by cleaning it by (wire brushing) the parts to be able to solder the terminals. An appropriate soldering flux must be applied for soldering to steel and brass. You could use Baker’s Soldering Flux fluid to the steel parts and rosin cored solder to brass parts. I use ‘Duzall’, pronounced ‘Does-all’, a one soldering flux that does steel, copper, brass, stainless steel. It will work on slightly tarnished brass if given a short time to work. In any case the cleaner the metal the better and easier the job.

If you are handy with a multimeter, set it on low ohms, you may like to read the resistance of the relay coil before you start the restoration, it is the top two terminals furthermost from the +ve bolt terminal, it should read between 17 and 22 Ω ohms (depending on brand of relay), if it is any higher, then soldering is necessary.

Before dismantling the relay, it is easier to lightly hold the relay in a vice and use a small wire brush wheel in a slow speed battery drill to clean the brass terminal tabs and the tops of the steel rivets. When this is completed, solder these terminals and then start prising up the 8 steel tabs that secure the relay body to the housing and only open them up enough to wriggle the insides out of the housing. These tabs are easily broken with too much bending.

On opening up the relay check the inside for rust on the +ve terminal bolt head and the contact bracket, if there is rust, undo it and wire brush both ready for soldering together. Note a heavier wattage soldering iron may be required here to get adequate heat to the job. Wire brushing the +ve bolt head and the contact bracket back to clean steel is going to expose it to rusting again, so it’s best to assemble bolt and bracket back together and solder them together. Don’t forget to solder the centre most terminal tab to its steel rivet, this is the other side of the contact to feed the starter motor solenoid, a good circuit is necessary.

While the relay is apart, resolder the coil side terminals (where the coil enamelled copper wires attach).

Check the contacts for pits/burns and if necessary, lightly file the faces clean. Make sure the contacts are not loose, I’m fussy here and even clean and solder the back of the contact to the bracket where it is riveted. Any filing of the contacts will increase the contact gap, so press down on the armature part to ensure the contacts are loading up. Slight bending to the bracket may be necessary to adjust the contact pressure.

Before fitting the completed relay back into its housing, its best to bench test it, i.e. apply 12 volts DC to the coil terminals, a firm click should be heard from the relay indicating a healthy circuit. Operate the relay several times and note that the contacts are firmly loading up. If it does this, all is OK.

Reassembly to the housing. No doubt you noticed on disassembly the cork gasket has disintegrated. Don’t worry about it, you can use a smear of grease or gasket cement or even silicon in place of it. Note, just before entering the relay into the housing observe the little felt covered breather hole in the housing, this is the bottom of the relay, so make sure the +ve bolt terminal is at this end of the housing. Bend the housing tabs back over the insulated board and install back on the firewall of your car. Reconnect it.

Final note. When sliding on the top two quick connect lugs to the coil circuit of the relay, ensure they grip reasonably firmly to the brass tabs, any looseness here will also give unreliable starting!

I’m happy to demonstrate the above procedure if necessary.

Below is a sketch of the Neutral Start Relay’s terminals with a schematic diagram of how the internal connections are made in the relay. Also, the destination of the external terminal connections.

Footnote: If a number of people are interested in “Duzall” soldering flux, perhaps we can purchase a bottle and decant it out into smaller bottles. I’ve had my bottle for 30 years and it is nearly empty. The label has disappeared; I think it holds 4 ozs.

In the urgency to complete this story I have not checked the internet to see if there is in fact a direct replacement available to avoid this procedure. If anyone knows of such a direct replacement, then we’re all ears!