Bypassing the clutch switch

[Paul Workman]

Originally Posted by max76

Ok Paul....
So, before i install the second relay i want check the old relay and see (if it's possible) if internal components are damaged.
If they are damaged, first thing is change the old relay (obviously)...so, maybe the problem is only that.
This saturday i think to have just a little time to remove the protection and look the old relay conditions. I also can restore the clutch switch...
Someone, here in Italy, say to install a push button (temporary) to connect directly the battery with the starter, this in case i have te same problem, i can try if the problem is the relay or the starter...
Could be a different solution?

I don't know if you can open the old START relay to inspect it w/o destroying it. OR, once you've removed it, would it not make sense to just replace it with a new one and not worry about the old one.

A push-button solution, making a direct battery to starter connection, as a back-up, could work.

And, then there's the starter solenoid contacts - which can also become worn out - arching again - nothing you can do about that except replace the burnt posts and solenoid armature/contact ring (or recondition the copper contact ring with some sand paper (is what I did).

[max76]

The first thing i'll do is replace the starter enabled relay, once i have the new one i'll try to open the old one, just for curiosity...

Yes, the push-button is to check (when happens) if the problem is the relay or the starter.

Last year, when i change the injector i replace also the copper contact into the starter, new ones and with little more thickness.
Now, there are some other things could be bad into the starter?
There are modification required on the starter?

[Paul Workman]

Originally Posted by max76

The first thing i'll do is replace the starter enabled relay, once i have the new one i'll try to open the old one, just for curiosity...

Yes, the push-button is to check (when happens) if the problem is the relay or the starter.

Last year, when i change the injector i replace also the copper contact into the starter, new ones and with little more thickness.
Now, there are some other things could be bad into the starter?
There are modification required on the starter?

Far as your questions regarding the starter, I've replaced the electrical contacts, but as for any other aspects regarding failures, I would refer you to Marc Haibeck who has seen many more starters than I ever hope to!

[Dynomite]

Paul.....what is the Bold Red Line? I am assuming that depicts the current path through the relay we install without showing the relay?
Nice diagram.....
thanks,
Cliff

Originally Posted by Paul Workman

90-92 Clutch schematic(1)


Paul
___________

ref:
(1) Marc Haibeck article posted in HOTB.

If it were not for the fact the LT5 starter is buried deep under the Plenum, refurbishing the starter Solenoid would be a piece of cake.

Starter Contacts.
The Starter Solenoid is shown in the left photo with slight burnt contacts in right photo.

The Solenoid contacts in left photo were wire brushed clean in right photo.

[max76]

Hi guys, i don't understand a thing...in the 93/95 schematic, where is the second relay?
If i well understand put the second relay in 90/92 cars is to update the circuit like the most new ones...it's correct?

[Paul Workman]

Originally Posted by max76

Hi guys, i don't understand a thing...in the 93/95 schematic, where is the second relay?
If i well understand put the second relay in 90/92 cars is to update the circuit like the most new ones...it's correct?

Ah, My bad. I should have explained the schematics show the stock setup in the 90-92 and the 93-95. (Schematics from an article by Marc Haibeck appearing in the HOTB related to "NO START".)

The additional relay (not pictured) is inserted between the CLUTCH SWITCH and the STARTER on the 90-92 schematic. (On the 93-95 there is little reason to install the additional relay, unless the factory START RELAY is so difficult to get to [I don't know] that it justifies installing the axillary - simply to move the high current switching to a more convenient location.)

And Cliff, the RED line is the high current path. The GREEN line on the 93-95 schematic is the low current "signal path" showing how the CLUTCH SWITCH is isolated from the high current path; a marked improvement, methinks.

Hope this helps clear things up.

[Dynomite]

What is the input and function of the starter enable in the Central Control Module (90-92)?
The CCM function activates the Starter Enable Relay (90-92)?

Then we have the higher current load passing through the Clutch Start Switch (90-92) which we reduce that current load using an additional Relay which provides a much shorter and unencumbered path between the Battery and Starter Solenoid.

On the 90-92 we eliminate the ignition switch path between the battery and Starter Solenoid as well using the New Relay.
If we installed the New Relay on the 93-95 we would be using direct current between Battery and Starter Solenoid not relying on current passing through the Ignition Switch (in that regard the same benefit as on a 90-92).

[max76]

Sorry...what is HOTB????
Thanks

[Paul Workman]

Originally Posted by max76

Sorry...what is HOTB????
Thanks

Sorry. HOTB (aka "Heart Of The Beast) is a periodical magazine available to ZR-1 NetRegistry members only (on line). No matter, far as this discussion is concerned, as I lifted the pertinent schematics from that article for this discussion - but do credit the schematics to the author (Marc).

[carnold]

Looking for a start cure. I have a 90 ZR1 and for years it starts fine but after I stop and leave it for an hour or so and come back I push in the clutch, turn the key, all proper lights come on but starter will not turn over. I leave it for 2 or 3 hours and it will then start fine. I bypassed the VATS system but still have the problem. Is it the clutch switch or the starter relay or something else. It is a 3700 mile car.