Location of Clutch Start Relay

[Jetjock]

I looked in the FSM and can not find where the clutch start relay is located. Does anybody have a picture of the location of the clutch start relay? I have a 93 ZR-1.


Roy

[We Gone]

Safety switch?

Remove the hush panel under the steering column, remove your drivers seat. lay on your back with your head against the clutch peddle and you'll see it...LOL yes its a pain in the A$$..

[Jetjock]

Safety switch?

Remove the hush panel under the steering column, remove your drivers seat. lay on your back with your head against the clutch peddle and you'll see it...LOL yes its a pain in the A$$..


I know where the clutch safety switch is. It's the clutch relay switch that I was looking for. I think that it is in the engine compartment. I have a 93 ZR-1. It's different than the earlier models.


Roy

[Marc Haibeck]

The starter relay is located under the driver's hush panel. It's under the aluminum crash support panel. The starter relay socket has two yellow wires, a yellow/black wire and the purple wire that goes to the starter. To bypass the relay insert a jumper between relay socket pins 30 and 87.

[Jetjock]

The starter relay is located under the driver's hush panel. It's under the aluminum crash support panel. The starter relay socket has two yellow wires, a yellow/black wire and the purple wire that goes to the starter. To bypass the relay insert a jumper between relay socket pins 30 and 87.



Marc, thank you for the help. However, I do have one question. Paul Workman referred to it as clutch start relay. One of the FSM's refer to a start enable relay and the other FSM refers to as a start interrupt relay. I'm taking a shot in the dark but I'm thinking that we are all talking about the same relay since it has the wire color coding that you have refer to. Thank you for the assistance.


Roy

[Marc Haibeck]

Hi Roy,

Yes, all of those descriptions apply to what I call the starter relay. You know you have the correct relay when you see the 5mm/10 gage purple wire connected to it.

Note that on a '93 and up cars, if the starter relay is bypassed the engine will crank without pushing down the clutch pedal. Even if the clutch switch is still connected. The clutch switch controls the relay, not the starter on the '93 - '95 cars.

I think that it's good for the crankshaft thrust bearing to not have the pedal depressed when starting. That way there is no load on it before oil pressure builds.

[Jetjock]

Thanks for that information. On my 92 Z, it wouldn't start until I bypass the clutch safety switch. Never had a problem since then. I do the same thing to my 93Z, I still had a problem starting. The relay could be going bad so that is why I asked. Thanks for the help. Now if I could just get my 92 up there for some TLC.



Roy

[Dynomite]

Just bypassed my Clutch Safety Switch on 90' #3032 and 91' :thumbsup:
I made extra Bypasses (each about 3" long) for my other 90's.
I left the original Clutch Safety Switch in place.

https://cimg9.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/400x400/80-c1f707d9_fb50_43d0_a912_39981de80804_e5a3a3544a0d5 78004ed995e45a3917469f1408e.jpeghttps://cimg8.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/400x400/80-img_1469_b49ba8efba92ca4866612b26d35890ce13400f94. jpeg

The Electrical Bypass (3" pre-soldered connector) can be installed in 10 min by removing the front two, side two, and bottom three Hush Panel screws (7mm hex head) as well as the nut from bolt holding Hush Panel up on the Fire Wall (Drivers Side).

The Hush Panel Light has to be unplugged once the Hush Panel is loose.

The Clutch Safety Switch Connector is easily identified with the two larger gauge wires (yellow and purple). The yellow wire controlled by the key switch and the purple wire to the Starter Solenoid (or in my case the added Starter Relay installed under the ECM).

The Clutch Safety Switch connector can be easily separated with one locking tab release. The end of the connector with the yellow and purple wires has two electrical tabs included as shown. The other end of the connector going to the Clutch Safety Switch can be tucked away under the steering wheel.

https://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/400x400/80-img_1462_65113bf7563ee31ef9db0dcabdd2d0f7cf16a93f. jpeghttps://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/400x400/80-img_1465_5a59a063cb49362efd7dfcd5038734e839b33310. jpeg

The 3 inch 12 gauge yellow connector Bypass can be connected to the existing tabs within the connector without any electrical tape required since the connectors are very well insulated within the connector and very tight. The Connector with the Bypass can then be tucked upward above the Hush Panel and the Hush Panel placed back into position and secured by the seven screws (7mm hex heads) and the Fire Wall nut and washer.

https://cimg8.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x800/80-img_1466_ecad2244a8638682dca410165164ba6212d639db. jpeg

You now have a Start condition without the requirement to depress the Clutch as long as Transmission is in Neutral. You can depress the Clutch to make sure you do not lurch forward just in case the transmission was left in a gear.

You also now have eliminated one of the NO START issues associated with the Clutch Safety Switch. The original Clutch Safety Switch is left as installed with no issues.

Post 293 - Bypassing Clutch Safety Switch (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-15.html#post1596384616)

[We Gone]

Roy glad you found what you were looking for....

[Paul Workman]

This is the graphic I contributed to an presentation by Marc (IIRC).

Anywayz... Old info for most of us, but for the benefit of the new Z owners, this may clear up some questions?

The 90-92 Zs routed the starter solenoid current through the clutch safety switch that was activated with the clutch pedal, whereas the 93-95 Zs utilized that switch to activate a relay to handle the relatively high current that clutch safety switch had to handle.

That clutch safety switch (located on the clutch pedal arm) is difficult to get to, requiring one to remove the seat so one can lie on his/her back and access/service the switch. However, due to the current load, it is only a mater of time before that switch will fail again. The solution was to hand off the start solenoid current load to a relay and simply use the clutch safety switch to activate that relay - which was a factory modification present on the 93-95 ZR-1s.

Two solutions for the 90-92 model years:

1) Install a starter relay*: Cliff (aka Dynamite) and I colluded to develop a modification for the 90-92 MY Zs by installing a relay and routing the clutch safety switch to control that relay, similar to the 93-95 solution. (See SOLUTIONS sticky for details.)

*NOTE: This relay mod applies only to the 90-92 MY Zs as the later 93-95 models already have such a relay mod installed as a factory-designed modification. Thus, this makes an additional relay (in series) redundant and unnecessary.

2) Bypass the clutch safety switch (with a jumper or solder join the leads together). This modification eliminates the (nanny) safety switch resulting in the starter being activated with the ignition switch alone. One must either press the clutch when starting the engine unless the transmission is in neutral. Otherwise, the car will lurch when the starter engages creating a potential hazard; a hazard increased if the engine starts as well!

[Dynomite]

2) Bypass the clutch safety switch (with a jumper or solder join the leads together). This modification eliminates the (nanny) safety switch resulting in the starter being activated with the ignition switch alone. One must either press the clutch when starting the engine unless the transmission is in neutral. Otherwise, the car will lurch when the starter engages creating a potential hazard; a hazard increased if the engine starts as well!

Post 293 - Bypassing Clutch Safety Switch (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-15.html#post1596384616)

Many of us are much more familiar with standard transmissions not having a Clutch Safety Switch :D

You can actually install this Clutch Safety Switch Bypass on the road if you have the 3" Electrical Bypass made up as a spare and a 7mm socket (1/4 inch socket wrench) :thumbsup: