Bypassing the clutch switch

[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.

[Dynomite]

Originally Posted by 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.

Does the starter solenoid move and no start or solenoid sticky?

Do lights dim when you turn key to start?

I always install the Starter Relay and along with that always recondition the starter solenoid and points (and check armature bearings for smoothness and starter Brushes).

[carnold]

Lights do not dim. Solenoid does not click. It acts just like a VATS problem but it has been bypassed.

[Dynomite]

Originally Posted by carnold

Lights do not dim. Solenoid does not click. It acts just like a VATS problem but it has been bypassed.

It sounds to me like the starter solenoid is sticky after heating up and has to cool down to activate. Assuming your battery is fully charged. The other items that may cause your starter issue have nothing in common with the engine temperature as far as I know.

I assume you installed the Starter Relay taking direct current from battery to Starter Solenoid when activated by a lower required current to activate the Relay itself through the Clutch Switch.

[carnold]

No have not touched clutch switch or added relay. It is bone stock. I am to old to be removing battery boxes and adding another relay. Could it be the clutch switch or original relay?