So, I've been trying to get this thing running again. I backed it up onto some ramps last week, and now it's no longer cranking over. I can't here the fuel pump engage anymore. It doesn't seem like the dash is getting the power it used to either, although it does still light up and do a systems check. Its just.. dimmer. When I do attempt to start it, it clicks and the dash goes dark until I release the key. It has a good agm battery which is fully charged. New ends on the battery cables as well (except for the ends which are connected to the block and wherever the positive cable is going.

Note - Ive been trying to wire in a manual switch for the radiator fan because it wasn't kicking on when it came to temp. I diconnected the cables to the fan and capped them off, routed the black to positive battery, then red to lead on the manual switch, then earth to ground in cabin. Seems to work fine, but I DID plug in the little led light to the fuse panel which quickly got very hot. Disconnected as fast as I could. Buúuut ever since then I havent been able to get it started again..

Im also including pictures of how the cables are placed in the engine bay.. Im finding a lot of loose stuff or cables that look like trash. Anyone know what they go to?


What are those harnesses attached to the side? And why does my negative battery post need an addition ground? Is it needed?

Red cable is the fused line to the fan

Is the pictured positive battery cable running to the starter, or? How are these usually run?

Heres something I noticed next to the battery. That red cable is trashed, but I have no idea what these go to. Any ideas?

There are actually three relays here. Two pictured, and a third behind them. What do these do?

Heres where that third relay is. Any ideas? Also, whats the green cable connector supposed to do?

And for your benefit, I plugged the led into the back of here - top left. Did I royally F up?

Sorry for all the questions, but the electronic stuff is NOT my strong suit obviously...I really dont even know where to begin here.

 

For general reference, an LED is a polarity-sensitive device. In one direction it will illuminate. In the other direction it will become an open circuit with sufficient ampacity. Thus, using an LED as a test lamp is always 50% risky.

 

Thanks Vader, and just for clarity, I was just trying to find a spot where the LED would illuminate when it I had the fan switched on, not to test for power. But I'll make sure to heed by your advice

 

The black hooded clip attached to the inner fender rail is a 20A fuse for the ECM and fuel pump. Of course, that fuse needs to be installed and intact.

The separate wire on the negative battery terminal is to ground the body/chassis separately from the engine ground.

Hopefully, that replacement (top post) battery is temporary, just to get the vehicle running. The Chinesium die-cast terminal clamps are not as effective as lead alloy clamps. The battery appears to be a AGM type (Optima?) and those have a long history of not tolerating underhood temperatures for very long. A serviceable (with cell electrolyte caps) side post battery will likely be a lot more reliable, but for now that one will work if it isn't already cooked and dead.

 

Is this a VIN "S" engine?

 

OKay I'll definitely double check that fuse along the inner fender. There's two there, so I'll just check both. Is there a specific way to test?

Battery is temporary, and I recently had it tested as good. My battery charger/tester charged it last night and things seemed fine with it.

VIN Is indeed an "S" engine

 

Checked both fuses in inner fender - both intact
Checked all fuses under dash - all intact
Going to replace the fusible link (pictured in photo number 4) hopefully today?
Let me know if you guys think of anything else

 

Id suspect those battery clamps... try twisting them to see if you can make a good contact... then try start it and see if it makes any diffeence

 

Haven't had a chance to fiddle with this thing unfortunately, but I'll take a look at those battery clamps and see if that'll make any difference.

I'll be replacing the link today hopefully as well

 

Alright, so I replaced the fusible link and tightened down those clamps but no dice. Heres a video of what I'm seeing - https://imgur.com/gallery/6vgPGqu

Editing to add that I still don't hear the fuel pump prime when turning the key. I'm not sure if that's audible in the video or not. I'm going to check the battery cable grounds are good and attempt to find the starter relay to see if that's good

 

#1) Is that the Cable you replaced? (PLEASE say yes)
#2) Do you have a Hayne's or Chilton's Manual at min or a GM Service Manual?
#3) My most valuable piece of advice, repair all Pwr/Gnd cables and connections, then with a fully charged battery grab a DMM w/ some jumpers hooked up. Connect Blk to Ground, Connect Red to Large Stud on starter and verify Bat Voltage. If solid, Connect Red lead to Purple Wire at the Starter then watch the DMM while "cranking", Get less than 9.5V? If you have a helper... connect DMM up to Battery and just watch Voltage while "cranking"... Get less than 9.5V?

Sounds like you have 2 options... Troubleshoot from the Ignition Switch forward to the Starter OR in reverse from the Starter up to the Ignition Switch.

 

#1) Is that the Cable you replaced? (PLEASE say yes) - Yes lol
#2) Do you have a Hayne's or Chilton's Manual at min or a GM Service Manual? I'll have to look. I recall the chiltons manual I had was off because of mine being a berlinetta, but I'd love to get ahold of a service manual
#3) I'll work on that as soon as I can

Appreciate the response!