Car will not start - electrical maybe? Funny HVAC Panel light behavior...

[kajcienski]

Hello all!
It has been about a year since driving my D regularly.
After having to change the fuel lines earlier this year, the little guy was running strong again!
Shortly after, there was an incident where when I turned the key to crank it, the lights went dark/off on the HVAC panel and cluster. No noise (silent) at that point and when the key went back to first position, the light were fine again. I left it overnight and it was turning over just fine the next day. At this point, I had been wanting to tidy up some electrical anyway (thinking if something was shorting I would see it), so I removed the center console and worked on that. After putting everything back together, things were fine again. I just tried to start the car and now we are back to the same thing. Though one thing I noticed is after trying to start it (lights go off), then in position 1 lights are back on, but then when I turn the key to OFF, the HVAC panel lights stay lit and then slowly dim down for about 10 seconds until the are completely off (they are LED). I don’t recall that ever being normal behavior?
My knowledge is average when dealing with issues on the DeLorean and have been very lucky.
Might anyone have any thoughts before I have to tow it to DMC?
Any help would be GREATLY appreciated!
I am fairly confident my harness cleanup behind the control panel/HVAC/Radio on back to the change holder under the center console is solid.
I am happy to try and provide more detail if guided.
Thank you in advance!
Matty

[David T]

My advice would be to start with the battery. Remove it, fully charge it, and have it load tested. If it is over 5 years old just replace it. Make sure the terminals are clean and shinny. See if that helps. Batteries do not store well unless cared for. Even then they get old and go bad. Keeping a battery fully charged during storage will minimize it's aging especially if you don't drive the car.

[Bitsyncmaster]

If your battery is good the first thing to check are the two feed through bolts and nuts behind the rear deck board. You have to remove the vertical board by removing the hooks on top which hold the net. Those feed through bolts often get loose and that provides the 12 volts and ground for all your electrical in the car.

[kajcienski]

My advice would be to start with the battery. Remove it, fully charge it, and have it load tested. If it is over 5 years old just replace it. Make sure the terminals are clean and shinny. See if that helps. Batteries do not store well unless cared for. Even then they get old and go bad. Keeping a battery fully charged during storage will minimize it's aging especially if you don't drive the car.

Hi David!
Battery less than a year old, has been tested. It seems like a bizarre acting short - are the dimming HVAC lights normal when turning key to OFF?
I’m hoping this isn’t a “hunt and peck” type electrical short issue.
My experience is limited with diagnostics.
Sigh...

[kajcienski]

If your battery is good the first thing to check are the two feed through bolts and nuts behind the rear deck board. You have to remove the vertical board by removing the hooks on top which hold the net. Those feed through bolts often get loose and that provides the 12 volts and ground for all your electrical in the car.

I guess just to clarify, lights, hazards, windows, antenna, etc. are all working strong when key is in position 1. When I turn key to TRY and crank, cluster light dim, HVAC lights go out immediately - dead silence (starter never engages). I stop crank position and everything pops back on and normal. I turn key position to off and HVAC lights start to dim (after car is off) for about 10 seconds. Battery is a year old and charged.

[Bitsyncmaster]

I guess just to clarify, lights, hazards, windows, antenna, etc. are all working strong when key is in position 1. When I turn key to TRY and crank, cluster light dim, HVAC lights go out immediately - dead silence (starter never engages). I stop crank position and everything pops back on and normal. I turn key position to off and HVAC lights start to dim (after car is off) for about 10 seconds. Battery is a year old and charged.

When you go to key position 2 your adding more load so a bad connection could make that feed through go open and kill everything. If it's not the feed though connections then you will need to trouble shoot with a voltmeter and schematic.

[kajcienski]

When you go to key position 2 your adding more load so a bad connection could make that feed through go open and kill everything. If it's not the feed though connections then you will need to trouble shoot with a voltmeter and schematic.

Oh boy... sounds like fun 😣.
I’ll check that connection!

[kajcienski]

Oh man...

Okay - I checked the connections that Dave mentioned - all good there.
However the way I had described it now appears to be different slightly.
- Position 1: All normal. Lights, antenna, windows, etc. are working and strong.
- Position 2: Does not try to turn over - complete silence. Red instrument cluster lights stay fully lit. Both radio and HVAC lights go dead. Antenna starts to go down.
- Back To Position 1: All lights return to normal.
- Off Position: HVAC lights immediately go out. Previously I had been getting a strange thing happen where the HVAC lights gradually dimmed for 10 seconds and then were off. Bizarre, no?

[Elvis]

well, does your starter relay click ?
is your starter stuck ? (Hammer)
are wires wires to the starter loose ? below the red rubber thing ? use a 13mm...

Multimeter and Schematic are also always helpful.

[David T]

Still *could* be the battery. Last thing to try is to use a jumper box or jumper cables with another battery. If you get the same results you probably have a bad starter.

[kajcienski]

well, does your starter relay click ?
is your starter stuck ? (Hammer)
are wires wires to the starter loose ? below the red rubber thing ? use a 13mm...

Multimeter and Schematic are also always helpful.

Had already checked the wires to the starter - all right there.
I’ll give it a whack and see where that gets me. I put in a new starter about 8 years ago, but I remember hearing some debate on the model I chose. I recall hearing a starter relay click (had panel open).
I’ll start with a whack though!
Thanks!

[David T]

It wouldn't be the wires to the starter, the "big" one is hot all the time (at least it is supposed to be). The little ones would not be able to dim the whole system without smoking. If the wack gets you going I would replace the starter. Possible the starter is stuck engaged to the flywheel and the wack will jar it loose. Could accomplish the same thing by pushing the car a little bit in gear. Should still hear the starter relay click even if the starter is stuck. Sometimes they will chatter.

[kajcienski]

It wouldn't be the wires to the starter, the "big" one is hot all the time (at least it is supposed to be). The little ones would not be able to dim the whole system without smoking. If the wack gets you going I would replace the starter. Possible the starter is stuck engaged to the flywheel and the wack will jar it loose. Could accomplish the same thing by pushing the car a little bit in gear. Should still hear the starter relay click even if the starter is stuck. Sometimes they will chatter.

Tried both whacking the starter and pushing car a bit in gear. No luck.
Relay clicks, so now I assume I should test power to the starter?
Is there an easiest/recommended test point?

Also to double check - I had mentioned that I just finished cleaning up the harness from behind the HVAC/Radio back to the change tray area. Does this issue sound like it could be related to anything along that stretch of the harness? I am pretty confident in the work I did there (and everything was working just fine after completion for a few days), but want to see if I can rule that out.

[David T]

The test would be to make sure there is battery voltage to the starter relay before the turn the key and when you turn the key. Then you check the voltage at the connection between the starter and the starter relay. Based on your symptoms I would expect when you go to the "Start" position the battery voltage drops to zero. That would indicate that the starter motor is bad. Really doesn't matter if it is the starter relay or the starter itself. When you replace the starter it comes with a new solenoid.

[Rhye]

Relay clicks, so now I assume I should test power to the starter?
Is there an easiest/recommended test point?

I'd just take a piece of wire to briefly short the battery and control terminal on starter solenoid and see what will happen.

[Ron]

I'd just take a piece of wire to briefly short the battery and control terminal on starter solenoid and see what will happen.+1 ...and if it doesn't turn over, I would jumper cable the battery (-) directly to the engine and try again. And if that doesn't work, pull the starter.

("It's always the grounds";-)