Electrical question: is this supposed to be here

[Tim555]

I am still chasing down a hot no crank issue with my 1991. The new starter didn?t fix the issue. I decided to see if there was a grounding problem. I pulled the battery and found the thick negative that I think goes to the starter area. It has a splice block on it that definitely doesn?t look like it came from the factory. For context, below my hand is the battery tray. I took it apart and reseated it better than it was before. Does this thick wire in fact go to the starter? Could this be causing my issue? It didn?t feel loose, but I definitely got it seated better than it was. I?m not holding my breath, but I?d be ecstatic if for some reason this fixed it. Other info that might help is at idle the turn signals seem a bit slow and the voltage gauge moves up and down when they are on.

Edit: the splice block was on the POSITIVE side coming off the battery and then going down to the starter area.

[Tim555]

Just got back from a drive. The hot start issue still exists.

[hotroddaddyo]

Have you confirmed the ground/negative cable connection is good? ... not just looks good but tight and not corroded at the frame.

[Tim555]

Have you confirmed the ground/negative cable connection is good? ... not just looks good but tight and not corroded at the frame.

You mean the ones by the bellhousing? I will check those next.

[hotroddaddyo]

Specifically confirm proper ground of negative battery cable and any ground wire/cable/strap between engine and frame.
Perhaps your starter isn't getting sufficient ground source, so maybe try connecting a single jumper cable from an appropriate clean location on engine block to an appropriate clean location on frame (to create new/additional grounding)... if nothing yet, try jumper from engine block to negative battery terminal.
Heat expansion can compromise connections. I am thinking ground issue as you stated turn signal operation affects voltage gauge.... check that alternator wiring is secure, too.
If still not resolved, I recommend you check out the wiring to the starter solenoid.... unfortunately, it likely requires pulling plenum.

[Marc Haibeck]

The battery needs to supply 12.5 volts or more when the hot no start condition is present. Check the battery voltage with the ignition off and the doors closed.

The clutch switch is a suspect. An easy way to move forward is to install a 12 gauge wire to bypass the switch. The clutch switch has two black wires in a black connector. The other side of the connector has purple and a yellow wires. Jumper the purple and yellow wires together. Drive the car and see if this makes a difference.

[Z51JEFF]

The question is why is there this type of splice,is there an aftermarket stereo in the car?

[Tim555]

The battery needs to supply 12.5 volts or more when the hot no start condition is present. Check the battery voltage with the ignition off and the doors closed.

The clutch switch is a suspect. An easy way to move forward is to install a 12 gauge wire to bypass the switch. The clutch switch has two black wires in a black connector. The other side of the connector has purple and a yellow wires. Jumper the purple and yellow wires together. Drive the car and see if this makes a difference.

The clutch switch seems to work. When I turn the key with the clutch depressed the voltage (as indicated on the instrument cluster) drops. Without the clutch depressed, it rises slightly. Could the clutch switch or its associated circuitry be faulty and have a higher resistance than its supposed to even though it appears good? I did unplug it and tryjumpering the purple and yellow wires but this didnt seem to work. I?ll try with thicker wire since all The starting current has to pass through it. The next step is just to wire in a relay to send current directly from the battery to the starter. The process is described in this post for anyone else who?s having a similar problem https://www.corvetteforum.com/forums/c4-zr-1-discussion/1415202-dreaded-no-start-fixed-for-good-hopefully-2.html

Still didn?t get a chance to warm the car up and try connecting a jumper cable from the engine to the battery or frame to rule out an engine ground.

Edit to add I did check the battery voltage with the car off and doors closed. It?s 12.5. It?s a new battery from the fall. I?ll have the local advance auto load test it. I?ve seen batteries before that seem good but fail a load test. That said, when it does start it cranks over pretty fast and it doesn?t sound like the battery is weak.

[Tim555]

The question is why is there this type of splice,is there an aftermarket stereo in the car?

The block just splices the positive battery cable. It doesn?t split it. There is an aftermarket stereo but it has its own lead off the positive battery terminal.

[Tim555]

I may have bigger problems to deal with. When driving the car to warm it up it started making this noise. It happened abruptly during easy driving (off throttle, in town going down a hill at maybe 30mph). It sounds top end.

https://youtube.com/shorts/bMqIPn26riE?si=62JLZIm1N9ZcjiIc

[1991 Corvette ZR-1]

Sounds like one of the lifters is not happy. How old is the oil? Is the level within the hash marks on the dipstick? I have an old beater four cylinder that makes the exact same lifter chatter noises if the oil gets too low or the oil is past due for changing.

[Marc Haibeck]

A lower pitch click could be from the cams snapping over center due to slack in a secondary timing chain. There must be at least 10 psi of oil pressure to keep the chain tensioned.

The same sound could also be caused by a leaky check valve in a chain tensioner. Try to identify the source as from the left or right bank. The retainer for the check ball could be loose. If so, the tensioner can be repaired rather then replaced.

[Tim555]

Sounds like one of the lifters is not happy. How old is the oil? Is the level within the hash marks on the dipstick? I have an old beater four cylinder that makes the exact same lifter chatter noises if the oil gets too low or the oil is past due for changing.

Oil was changed in February. Level seemed good but I?ll check again.

[Tim555]

A lower pitch click could be from the cams snapping over center due to slack in a secondary timing chain. There must be at least 10 psi of oil pressure to keep the chain tensioned.

The same sound could also be caused by a leaky check valve in a chain tensioner. Try to identify the source as from the left or right bank. The retainer for the check ball could be loose. If so, the tensioner can be repaired rather then replaced.

Thanks Mark. I?ll take a closer listen to it and see which side it is coming from. Does the engine have to come out to repair or replace a tensioner?

[davegarcia]

The light for the airbag on my 1990 z, and the seatbelt light on the dash come on while driveing the car. Never has done that before. Unpluged the battery to see if that would reset the computer. Lights are still on after hooking up the battery. Any ideas what could be the problem? Thanks in advance, zr1dave@hotmail.com

[hotroddaddyo]

https://www.corvetteforum.com/forums/c4-tech-performance/4318954-the-1990-dreaded-infl-rest-and-seatbelt-light.html