Mystery Electrical problem
 

I cant seem to figure this one out...Im over looking something and hoping a recoveree from this plague can help direct me as to what the problem is.

My 1991 22RE pickup is for sale as I bought another truck...therefore it sat for about a month. it started up and ran and worked fine, until one day I thought the battery died from sitting for so long without having been started.

The truck wont start by key, and is throwing NO Codes. The battery is 12.3V truck off, 14.4V truck running. when driving (bump start) if you use the turn signals or reverse...its like it kills the battery and the gauges die, drive a little more and then they eventually slowly come back.
at idle it will regain its "lost charge" but as soon as you trun the key off, the relay just clicks when you try to start it again.

Starter was pulled off and inspected, its still good,and only 4 months old.
THe 14.4V reading on the battery when running leads me to belive the Alternator is good as well.
I cleaned and reconnected the previously fixed bad ground on my ECU.
Cleaned terminals and various other grounds like batt-body,block-body, Starter power terminal-batt, eng-batt.
Back when my truck was running and drove fine, I can remember getting the odd No ing start signal code from time to time, but it still ran and started fine...that went away for good when I put in a new starter.

Please help Im at my wit's end! sorry for the long post, just wanna get the info out there.
thanks

Take the battery down and have it load tested.
If the battery has a bad cell or two (or three even) it will show a decent rest charge (12v+) but loose that charge fairly quickly if a light is on or the radio or hazards, or even leave the key "on" for a few minutes, but it will recover quickly as well once the engine is running, and show a good charging state, 14v+ with the engine running.

+1...:)

I have a load tester...I'll try that. not sure It battery, since I've tried the battery thats in it as well as another from a truck that starts and drives fine on the key..
THanks

Not trying to be difficult but I don't quite get what you mean by that.
Your battery is fine in another vehicle? Another battery is fine in your truck?

sorry my last post shows that I must have had a brain lapse or something.
The battery that was in my pickup when It last ran and drove and started by key worked fine. Then It sat for about three weeks. Upon start up I thought the battery was dead because the volt meter was very low like barely 12V...so I assumed it was dead, I tried jumping it and charging it and neither worked. So I pulled that battery in my truck and swapped it out for one or similar size out of my Dad's 1st gen. Tundra. (the tundra started fine on that battery)

My problem is that My pickup will not start by key. if bump started it runs fine, but when the reverse lights are used or turn signals, the radio and gauges die...drive a little more or let it idle a while and they come back to life...the minute i try to turn the key to crank it, click click click goes the starter relay.

Im taking a stab at it being a no ingition to starter signal, but its not throwing any codes?
I dont know what to look for other than chasing down wires. any likely culprits?

I mean what could go wrong during 3 weeks of sitting with no use that would cause it to not start on the key?

Well, likely nothing went wrong while setting other than maybe the battery discharged.
When you went to start it after setting, then tried to jump it and charge it, it's possible high current (caused by low voltage) damaged the ignition switch, particularly if the switch was already nearing its end of life.
I would try jumping the starter to see if the battery will turn the engine over that way. If that works, you know the battery can supply ample current.
That leaves us with the ignition switch contacts or an issue between the battery and the ignition switch.

Test for voltage at the starter...

Make sure your alt is up to the task. ITs only 60 amp from the factory, so if its messed up it might be your problem...?

ok, I'll post voltage readings when someone is turning the key to start.
and the load testing results of the battery

Voltage at the starter is 12.35 and that's from battery then is about the same when grounded through frame while ignition is turned to start.
I can hear my starter relay click a lot, when I try to crank it over. I did check the relay for continuity and it appears to be fine.
still am at a loss and losing patience, any suggestions on whats the culprit?

f-ed up started relay...replace and see what happens

x2 on starter relay

ok thanks, I think I have one to swap out and try. will post results

ok the starter relay is in the Drivers side kick panel. I do not have another relay to test it. I dont have much time to look at the truck. and I am very close to sending it to a mechanic.
Im on my last legs with this thing. Its very frustrating, because It runs and drives fine, and did when I parked it last. Its like there is a short in the electrical system and power for the signals/gauges and reverse lights and dash is there, but intermittent at random load intervals. (Like if I were to signal & reverse a few too many times). I am beginning to wonder if the ignition switch for the key just let go on me?
anyone ever have this problem before?

I'd like to provide closure to this thread so that It may help other members on Yota Tech.
I have since sold the truck and its problems have been resolved.

The truck had an aftermarket alarm sys, which I removed because It was glitchy long before this issue ever came up. It also had an aftermarket stereo system and aftermarket trailer wiring. Both of those were working properly. All of the grounds were intact and working properly.

The truck needed a new Ignition switch...$700 approx CDN. Once the new Switch was installed, the buyer had a properly functioning vehicle again.

I think you got screwed on the price. You could have bought a new ignition switch for under a hundred dollars and install it your self in less than two hours and saved a lot of money.