1990 V1500 Suburban No Power No start

[RacingTurtles]

INTRO

Hello and thank you for clicking on this thread. My name is Apu (yup, get your jokes goin) and I've got this old gal. Shes a 1990 GMC Suburban Geneva edition. I made an introduction thread when I first got her. She's been running fine for some time, had no issues and even loaded her up and helped my gf and her dad move to their new house. The engine ran perfectly fine. I know that there are some wires disconnected at the lower interior side under the steering column. My rear high top brake light doesnt work, my interior hvac panel,radio, and electrical door locks do not operate. The window controller from the drivers side works and all windows operate normally. Other than that the truck operated normally.

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Geneva suburban by , on Flickr

It is a 1990 GMC Suburban V1500
5.7L gas engine with 4x4 Auto transmission
There are some extra electronics with the high top roof and interior lights. I do not see any other modifications besides what I have seen to be standard with the Geneva package.




My new job had me traveling back and forth to California so I haven't driven her much. She worked fine on September 2 when I had to make an emergency Vet visit for my dog. There were no issues driving her then. I had to fly out the next day and came back on September 6. There was no rain for those days I was gone and no one operated the vehicle.

PROBLEM


September 7 I tried to start the Suburban and no go. I inserted the key while it was in the off/lock position. Upon inserting the key, I heard the continuous beep/key in ignition reminder beep. I turned it forward to the run position. The gauges lit up/Check engine light/ dummy lights are on. Volt meter showed less than 12 volts

So my volt meter is setup to show 8 volts is the lower left tab,then the red area slightly above it, middle tab is 13 volts, and right tab is 18 volts. Normally it sits just below 13 at this point when the truck was working fine. Here is how it sits as I cycle through off, run, start.

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Geneva Suburban by , on Flickr

Turn key to the start position, I hear one click and at this point no start and all power is lost. I cannot determine where the click is coming from. It was as if the key was not inserted and everything reverted back to the position it would be at if the key was in the off/lock position.


Removing the key and reinserting it in the off/lock position results in a faint continuous beep. moving to the run position, the voltmeter shows around 8 volts (needle moves up a little) . Move to start position and it doesn't do anything, no click this time. Repeating the process shows no electrical action.



DIAGNOSTICS

I referenced the FSM found at

http://www.1990suburban.com/repair_and_service_manuals/index.cfm

Section A Page 36 which is page 49/402 when using the PDF has a flow chart for start and charge.

I jacked up the vehicle to have easier access to the starter. I put a test light to the purple wire at the starter and showed no voltage(light not on) and the multimeter showed 0.6 mV while in the off position.
Now I had a helper turn the key and try to start it. Still showed 0 V and starter solenoid did not click.

Now step 5 says to test connector at ignition switch. This means I have to remove the lower column access panel, unplug the connector C209 and test it. Step 5 says if that C209 connector shows voltage that I need to replace the ignition switch which I hear is a pain in the ass. If it shows no voltage then I must replace the open at the RED(2) wires and fusible link at the junction block.




In an effort to save some time, I am asking if you have any suggestions on fixing this, preferably in a
faster method.

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Geneva Suburban by , on Flickr

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Geneva Suburban by , on Flickr

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Geneva Suburban by , on Flickr

These wires have been accidentally yanked on and they fell out. They are for my Radio and Hvac I believe. When I first put a battery in the truck after taking delivery of it, the only thing that came on was the AC. Then I accidentally touched these wires and radio and HVAC wont come on. They only had hooks on them and by accidentally moving the wires they just became unhooked from whatever they were on. I taped them up and kept them out of the way because I can still start and drive the truck without them. There is one red wire up top connected to something on the fuse block. A lower left blue one, a lower middle red one with a female end, and a lower right blue one. I just taped them up as you can see.


UPDATE #1

Current status

I am now opening the column panel to test the C209 connector. I will report back once I have more details.

With the flowchart saying to repair the open at the red (2) wires, I would assume that wire is meant to show continuity whether it may be with the key in off or run position.





UPDATE #2

I tried to get to the C209 connector for the ignition switch. I couldn't even see it. I may have seen that metal mounting plate thats on the back of the ign switch but I could not find that damn connector. I only took off the front plate, I didn't drop the column or anything.

I verified that all things had battery voltage at the junction block.

For ***** and giggles, I hooked up my emergency jump starter/battery to the truck battery, set it to jump start mode, and it slowly cranked at first but started up and ran normally.

With the truck running normally, I noted it said battery was at 13 volts at the truck volt meter. I had my brother hook up the multimeter to the battery and pay attention to the voltage as I held the engine at different rpms to see what it did. At idle, multimeter showed 14-14.25 Volts. This is with no load on the engine.

Then we went to different rpms and it went anywhere from 13.8-15 volts from idle up to 5000 rpm

I repeated the same test as above except with turning on my daytime running lights, headlights, and all interior lights and fog lights in that sequence. Engine did not skip a beat and voltage stayed around 14-14.8 volts.


Now we moved the positive cable to the connection at the back of the alternator. I repeated the no load on engine test with different rpms and voltage stayed 14-14.8 volts.

Now we moved to this test except with load on the engine. It was the same sequence listed above but this time, I turned on the lights at 2000 rpm. There was a momentary drop in rpm and the check engine light came on. After a few seconds the CEL went away. Still at 2000 rpm, we went to 3000 rpm. Daytime lights, headlights and once I started the interior lights, my brother said there was another drop in voltage and some more momentary hesitation.

Turned off all load. Took it to 4000 rpm. Did the headlights and my brother said it dropped to 10 volts and engine just died. At this point we are back at square one.

I hooked up the jump starter and there is nothing when I turn the key.

 

[eskimomann209]

Soo sounds like a bad starter to me. Pull it off and take it down to the shop to be tested. Most of tHe big box parts store will test it for free. Since your taking it down have the battery tested too. It makes no sense that it clicked before ( click is the starter you’re hearing) then when you get down there with your voltmeter it doesn’t want to start and has no volts at purple wire.

Take em off have them tested. Clean the mating surfaces of the starter to block and tranny. Bad grounds easily cause this issue. As well as loose battery posts. Corroded posts etc. I doubt the problem is wiring all of the sudden. I would like you to reconnect those blue wires. Looks like they’re male and female pin type connectors. Then wrap them in tape again. Or solder and shrink wrap em. That red one is a fuse. Go find out where that goes too. Dangling wires is never a good thing. On the red one the other side may have current, either way hot wires tends to make a mess of elec tape. And a direct short will ruin your day. You might wanna check all your fuses now too .... I say all of them because who knows what the last guy did.
Also if all else fails wanna sell me your speedometer?

 

[RacingTurtles]

Soo sounds like a bad starter to me. Pull it off and take it down to the shop to be tested. Most of tHe big box parts store will test it for free. Since your taking it down have the battery tested too. It makes no sense that it clicked before ( click is the starter you’re hearing) then when you get down there with your voltmeter it doesn’t want to start and has no volts at purple wire.

Take em off have them tested. Clean the mating surfaces of the starter to block and tranny. Bad grounds easily cause this issue. As well as loose battery posts. Corroded posts etc. I doubt the problem is wiring all of the sudden. I would like you to reconnect those blue wires. Looks like they’re male and female pin type connectors. Then wrap them in tape again. Or solder and shrink wrap em. That red one is a fuse. Go find out where that goes too. Dangling wires is never a good thing. On the red one the other side may have current, either way hot wires tends to make a mess of elec tape. And a direct short will ruin your day. You might wanna check all your fuses now too .... I say all of them because who knows what the last guy did.
Also if all else fails wanna sell me your speedometer?

So the way I see the wiring is two wires from positive terminal from the battery. One wire goes to the alternator. The other goes to the starter terminal. I verified 12.5 volts at both connections with the Engine off. At the starter, there is another red terminal that I assume goes to some junction block or fuse box. I could not follow the wiring all the way back as it was behind the engine and snakes its way up somewhere.

I want to assume its a bad starter or starter solenoid with my update #2 info that I added to the original post. I agree that it should have clicked again.

My battery posts and most of my power/ground wiring is garbage and has surface rust possibly internal rust.

 

[RacingTurtles]

Interesting that I am unable to edit the original post now.

Update #3

Took the battery to get tested and battery checks out. I didn't mess with the starter yet because the battery was much faster, and I live close to Autozone and Advance, something came up with the house, my moms car, and we are doing something to my brothers car as well.

I will report back after testing the starter.

 

[TerryRH]

Easier to follow updates with new posts

Really sucks chasing an electrical problem. still love the truck!

 

[highdesertrange]

most of the time when you get a click followed by nothing it's a bad connection on a battery cable. I would start my troubleshooting there. highdesertranger

 

[RacingTurtles]

Update #4

So just got back from the parts store, the starter was good.

To recap in short:

Truck has almost no electrical power to anything. The key is inserted and I hear the key reminder beep but no power to any accessories in acc position and no crank when in start. Removing and reinserting the key I lose the beep and there is no power.

Power test so far.

Battery was removed, tested, and is good.

Battery to alternator wire is good and alternator charges the battery (refer to test in update #2)

Starter has 12v at the big terminal. Purple wire has 0 v when in crank. Starter tested and works off the truck.


Junction block had battery voltage.






Things I can think of to test

1. Fusible link wire from starter to junction block. Unlikely since the junction block has power but still cross it off.
2. Two wires with fusible links from junction block to C100 connector. Where is this guy though?
3. Grounds- Battery to chassis & engine, starter ground, any other obvious grounds nearby.
4. Ignition switch. I am really not looking forward to it.

 

[yevgenievich]

I would also suspect battery cable connections. Failed start with a click followed by no power means there is a loose contact that likely arcs and stopped conducting.
Plus maybe something was left on and drained the battery. Or has a constant drain due to a fault somewhere. That can be traced with amp meter and pulling fuses out. Or a test light and pulling fuses out.

 

[Frankenchevy]

since you have 0v on starter solenoid wire in crank, but voltage everywhere else; it is likely you either have a fault in that wire or a bad ignition switch.

The purple wire can be traced back to the bulkhead connector and tested for continuity.

The ignition switch isn’t that bad. Take off the lower plastic part of the bezel, loosen the two bolts that hold the column up behind that plastic piece and loosen the two bolts for the column at the firewall. You should be able to carefully lower the column down enough to gain access. The switch is on top of the column. Is has an electrical connector, a couple screws and a rod that comes from the tumbler. Easy peasy.

 

[RacingTurtles]

Hey there ladies and gents, I wanted to give you an update.

To recap,
-Suburban worked fine, I went to California for 2 days, came back and no power to anything (headlights, nothing at all)
-Battery checked out, Starter checked out, did some testing according to the factory service manual.

I went down under to see what the hell I could figure out. The 2 AWG wire from Battery + terminal to the starter seemed like it was pinched where it sneaks through in between the engine mount and block. I pulled it loose from there.

I cleaned up
-Ground from battery to engine block & ground to radiator support
-Battery terminal connections and the connections at the starter.

Installed starter and battery and she fired right up.

I will put some silicone tubing to keep the big wire to the starter from getting pinched in that spot even though I dont know if that was really the problem.

In conclusion:

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[K201979]

My wife got stuck in my 78 g10. Wouldnt crank. Three guys(including me) crawling around underneath, under the hood, checking connections and banging on the starter solenoid. One guy reaches up and jiggles the column shifter. Starts right up. Neutral saftey switch with a little slop in it. Maybe that was your problem? Ive had problems with it in my truck too. It hangs down under the dash and comes disconnected on occasion. I crawl around checking everything every time until i remember it. Its where the purple wire goes.

 

[RacingTurtles]

Sounds frustrating as hell, did she have power to her lights? I did not have power to lights and that has power at all times with or without key in ignition.

I haven't touched anything on the column and mines an auto so I'm doubtful of it having a neutral safety switch.

I'm chalking it up to **** grounds/ loose connection.

 

[K201979]

Van lights did work at the time. Maybe your battery was dead at first? Van is an auto aswell(so is my truck, autos have a neutral saftey switch)and i hadnt touched anything in the column either, other than drive it. Probly is a loose connection somewhere, just sayin try jiggling the shifter if it happens again.

 

[RacingTurtles]

Interesting, thanks for the tip, I will keep that in mind if this acts up again.