Starter relay repair

[nick]

There has been some discussion on starter relays and their failure modes. Many express the notion that if you hear the relay clicking then it is not the source of your engine start problem. Not so. The clicking sound indicates that the eletro-magnet is pulling the contacts together. But the contacts may not be passing the desired voltage to the starter because the contacts are fouled. This is how you fix it.

Start by loosening the two screws at the bottom of the relay but do not remove them completely. There is only one screw showing in the picture.
[url="http://s615.photobucket.com/user/nickmi/media/20141126_093744_zps0d998bc9.jpg.html"][/url]

Next, remove the cover from the relay. I do this by cutting the bottom of the plastic so the cover will come off. You will need a pair of pliers to pull the relay out. Grab the center post and work the relay free. I leave enough of the plastic so that the relay will snap in later but the cover is now removable whenever you need to get into it.
[img][url="http://s615.photobucket.com/user/nickmi/media/20141126_093536_zps3e0274db.jpg.html"][IMG]http://i615.photobucket.com/albums/tt234/nickmi/20141126_093536_zps3e0274db.jpg[/img][/url][/img]

Notice that there is a notch on the inside of the cover. That lines up with the nub on the relay base when it is reassembled. The cover shown was removed by the PO. A much neater job of cutting the bottom of the cover can be easily accomplished.
[url="http://s615.photobucket.com/user/nickmi/media/20141126_093341_zps83ad8d33.jpg.html"][/url]

When removing the cover be careful not to disturb the fine coil wires that are attached to the contact posts on both sides of the relay. These are very easy to tear loose. Of the three relays I repaired I had to solder two of them back on. They are not on very securely.
[img][url="http://s615.photobucket.com/user/nickmi/media/20141126_083232_zpsf4d14baf.jpg.html"][IMG]http://i615.photobucket.com/albums/tt234/nickmi/20141126_083232_zpsf4d14baf.jpg[/img][/url][/img]

With the cover off remove the two screws that were previously loosened. You can now carefully maneuver the coil assembly away from the base of the relay. This allows you access to the two contacts that you hear snapping when the ignition switch is turned to start. The square contact will be black and possibly pitted. A small file and/or a small blade can be used to scrape the crud off. The same can be done on the other contact but I found those clean on all three relays.
[img][url="http://s615.photobucket.com/user/nickmi/media/20141126_084438_zpse911bec9.jpg.html"][IMG]http://i615.photobucket.com/albums/tt234/nickmi/20141126_084438_zpse911bec9.jpg[/img][/url][/img]

On this relay the blackened contact can be seen after the coil assembly was moved out of the way.
[img][url="http://s615.photobucket.com/user/nickmi/media/20141126_105607_zps6a7ce9c1.jpg.html"][IMG]http://i615.photobucket.com/albums/tt234/nickmi/20141126_105607_zps6a7ce9c1.jpg[/img][/url][/img]

Once the contacts are clean insert the two screws to secure the coil assembly to the base. Take care that the moveable contacts go inside the of the plastic lip on the relay base. Next, perform a continuity check on the coil to make sure that the fine wire was not broken. Also do a continuity check on the two contacts that were just cleaned. The right contact is attached to the center pole. This is not obvious when looking at the relay. Replace the cover and give it a go.



[img][IMG]http://i615.photobucket.com/albums/tt234/nickmi/TR7%201975/Yellow.jpg[/img]
nick
'79 TR7 DHC
'76 TR7 FHC

[FI Spyder]

I had taken mine apart when it happened to me a few years ago in Kirkland because I didn't have any contact cleaner to spray in the connector block. It was like brand new inside so I put it together a sealed it with glue. The problem has since moved to the contacts in the ignition module so will have to spray it alternatively with cleaner and silicone periodically to eventually clean it out.

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[nick]

What has me concerned is this. After I thoroughly cleaned the contacts and installed the relay, I left the relay cover off so I could observer its functioning while I started the car. What I saw was a spark from the contact each time that I relaxed the ignition switch after the start. I don't know if this is normal but I can see over time that an arc after each start will eventually lead to another failure. What I don't know is how many starts it will take. I observed this arcing on two of the three relays that I cleaned today. And before I cleaned the relays I did the same test when the relay was not working and the starter would not engage. In that instance, the contacts would snap closed without activating the starter. Each time I made an attempted a start, sparks were flying from the contacts. So once the failure mode starts, it is accelerated each time a failed start is attempted due to the increase amount of arcing that is occurring.

[img][IMG]http://i615.photobucket.com/albums/tt234/nickmi/TR7%201975/Yellow.jpg[/img]
nick
'79 TR7 DHC
'76 TR7 FHC

[FI Spyder]

Any time contacts brake or possibly make there will be a spark unless the current is cut off just before the action. I don't know if there is something in the circuit design/action that cuts off the current just before they break. For instance, I read some time ago (talking decades here) that in the distributor when the points make and break it's the capacitor that absorbs so there isn't a spark/arc. If the capacitor fails the points will not last very long.

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[nick]

So that begs the question what is there in the starter system, if there is anything, that should prevent the sparking? Because if there is nothing the relay won't last as you point out. I guess I should try an uncovered relay on my other car and see if I get the same result.

[img][IMG]http://i615.photobucket.com/albums/tt234/nickmi/TR7%201975/Yellow.jpg[/img]
nick
'79 TR7 DHC
'76 TR7 FHC

[Dukmans]

After some abuse of the startermotor (wrong wiring) I only hear a click and see a spark through the blue cover. Does this mean I blew the relay? I will anyway try the steps above and let you know about the progression.

[nick]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Dukmans</i>

After some abuse of the startermotor (wrong wiring) I only hear a click and see a spark through the blue cover. Does this mean I blew the relay? I will anyway try the steps above and let you know about the progression.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Prior to performing the instructions I posted, I attempted several times to clean the contacts without disassembling the relay. While the attempts always seemed to help, the relays were intermittent and unreliable. I was never able to get a good enough cleaning. Since I performed the above the fix both of my relays are operating very well indeed.
I've concluded I may have identified a symptom of a relay about to fail. If you turn the key and it turns all the way to the stop, and there is a slight delay before the starter runs, chances are that relay is in need of cleaning and will fail before long. Or if it takes multiple key turn to run the starter, that relay needs a cleaning. Since my repair, the starter runs immediately after the key is turned the slightest amount. It does not need to go to the stop.

[img][IMG]http://i615.photobucket.com/albums/tt234/nickmi/TR7%201975/Yellow.jpg[/img]
nick
'79 TR7 DHC
'76 TR7 FHC