HELP. No start

[Ozruss90]

1990 #1948. Went to take it to cars and coffee last weekend and engine wouldn’t crank over. Jumped in the ‘61 and took it instead. Just assumed it was a flat battery. Put the charger on and checked it a couple of days later. Still no start or crank, thought that was odd so connected a jump starter and still nothing. I have full full dash lights when key is first turned but once turned to the cranking position, dash lights go out and nothing happens. Not even a click from the starter solenoid.
Today l took the panel off under the steering wheel to access the clutch switch to test (wanted to change the footwell globe to an led anyway). Took the connector off the switch and bridged it . Still no cranking. HELP......
When lifting the hood to connect the jump starter, l noticed mice droppings scattered around the engine compartment. Thoroughly checked all visible wiring and nothing chewed but obviously can’t see if any damage under the plenum.
Would like to exhaust all other checks before resorting to pulling the plenum.
Any advise appreciated. Ps. Only done 11k

Cheers from down under 🇦🇺
Russell

[TX '90 ZR1]

Go to the "Sticky" by Dynomite. Lots of info on the "no start".
I would start with the thread labeled "Dreaded No Start".

[lfalzarano]

If your battery is older than 30 months, ditch it. You need a fresh battery that can crank a minimum of 690 CCA.

JMHO


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[RussMcB]

Maybe a candidate for the Purple wire relay mod? That seemed to be the fix for my no-start problem on my '91.

[Ozruss90]

Originally Posted by lfalzarano

If your battery is older than 30 months, ditch it. You need a fresh battery that can crank a minimum of 690 CCA.

JMHO


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Thanks for the tip. Thought the battery was younger than what it is. Decided to pull it out to have tested. Seller engraved purchase date on it, to my surprise it was Nov.2016. Will take it in tomorrow and have it tested properly. Any doubt and I’ll just purchase a new one.
Having said that, the battery had enough charge to power up all dash lights and with a fully charged jump starter still no crank or solenoid click.

[Ozruss90]

Originally Posted by RussMcB

Maybe a candidate for the Purple wire relay mod? That seemed to be the fix for my no-start problem on my '91.

Yeah, probably a job l should do anyway. Will read up on the procedure and see if it’s a job l can do myself.
Thought l might borrow an inspection camera and see if l can gain access to under the plenum with it to check out if any mice damage.

[JFFerner]

Depending on the type of "Jump starter" you used, it may have to at least partially recharge a dead battery before cranking the engine. Put your jump starter on and leave it charge for an 1/2 hour or more, then with the Jump starter still in place try cranking the Z.

[Paul Workman]

Before we start changing batteries, or even installing the auxiliary relay (never a bad idea, tho), Some basic troubleshooting is called for.

Check battery voltage. Fully charged it should read ~ 12.6 VDC at rest (14.7 when being charged).

The two most common "NO START" issues on the 90-92s are either the clutch safety switch or the solenoid contacts within the starter itself. And, a third relay is commonly known as the VATS relay (but unless your security light is flashing when you turn the ignition switch to START, that is not likely the issue).

Use the schematic provided that was published by Marc Haibeck that provides common voltages along the circuit WHEN THE IGNITION SWITCH IS IN THE START position.

IF the purple wire between the clutch safety switch and the starter has voltage on it when the ignition switch is in the START position, then chances are the starter solenoid contacts need replacement (will cost you about $10-15 for the Denso Starter Solenoid kit (See Jerry's Gaskets for that or whatever else your LT5 needs, including plenum gaskets you will need when you pull the plenum - a "rite of passage" for all ZR-1 owners!). Also, Most auto parts stores have the kits. Many domestic and foreign cars use that Denso starter(s).

Well, I don't want to jump ahead too far. But, refer to the schematic and use your VOM and trace the voltage from the battery to the point where you loose it. That will be the location of the fault.

The BIGGER POINT I'm trying to make is, before you start changing parts, VERIFY that the fault FIRST! Otherwise you'll be headed for a lot of frustration AND expense TOO!

[KFoster]

I have fought a lot of that. VATS bypass was first. That seemed to fix one problem. Then it would randomly no start. Hose came off the fuel pump. They use crap little plastic clamps. Replaced all those with stainless hose clamps. Next issue was the rod on the clutch had come off. Checked the starter and it seemed fine. Just did the purple wire bypass for the starter circuit. Cranks great, but haven’t driven it enough to know if that’s fixed or not.


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[Ccmano]

Originally Posted by Paul Workman

Before we start changing batteries, or even installing the auxiliary relay (never a bad idea, tho), Some basic troubleshooting is called for.

Check battery voltage. Fully charged it should read ~ 12.6 VDC at rest (!14.7 when being charged).

The two most common "NO START" issues on the 90-92s are either the clutch safety switch or the solenoid contacts within the starter itself. And, a third relay is commonly known as the VATS relay (but unless your security light is flashing when you turn the ignition switch to START, that is not likely the issue).

Use the schematic provided that was published by Marc Haibeck that provides common voltages along the circuit WHEN THE IGNITION SWITCH IS IN THE START position.

IF the purple wire between the clutch safety switch and the starter has voltage on it when the ignition switch is in the START position, then chances are the starter solenoid contacts need replacement (will cost you about $10-15 for the Denso Starter Solenoid kit (See Jerry's Gaskets for that or whatever else your LT5 needs, including plenum gaskets you will need when you pull the plenum - a "rite of passage" for all ZR-1 owners!). Also, Most auto parts stores have the kits. Many domestic and foreign cars use that Denso starter(s).

Well, I don't want to jump ahead too far. But, refer to the schematic and use your VOM and trace the voltage from the battery to the point where you loose it. That will be the location of the fault.

The BIGGER POINT I'm trying to make is, before you start changing parts, VERIFY that the fault FIRST! Otherwise you'll be headed for a lot of frustration AND expense TOO!

Thank you Paul, you beat me to it....

H