Ship of Theseus

Hello,

I did quite a bit of searching and failed to find any answers yet.

I have a 1988 Pickup 4x4, 22RE, 5 Spd. It has about 250k miles on it with a rebuild having occurred the winter before last.

The problem manifested itself a couple days ago when I went to the store and upon returning to my truck it decided to not start. I turned the ignition and had no juice anywhere. No ACC, no IGN, no RUN. Nothing. My emergency flashers didn't work, etc.

Upon getting my truck towed home I measured with my multimeter and I have 12.5 volts at the battery, and the 80A main fuse doesn't appear to be blown.
I did notice that the main line coming from the battery to the fuse box under the hood was very weak and only being held on by a couple threads of wire. I replaced this with the appropriate gauge of wire. I also took the leads off the battery and cleaned them, and also checked my grounds. I checked resistance and they measured as having no resistance.

After doing this I tried starting it and it doesn't work. I do get the dash lights to come on, but as soon as I try and start it doesn't work, everything shuts off. I can run my flashers, turn my headlights on, etc, but if I try to start it...no dice. After trying to start it I don't get any power to run lights or flashers, etc for at least 10 minutes or so and then I can run those accessories again....until I try to start it. It has a weird cool-down period. I think there may be a fuse somewhere that is only half blown and once it cools down it allows electricity to flow, but the task of starting it is too much for it to handle so it heats up and separates. I am just not sure where to look.

Occasionally when I turn the key now I get a buzzing from the driver side kick panel. I checked all the fuses there and they appear to be fine.

I am just baffled by the fact that I get power at the 80A fuse, even when I can't turn my lights on or flashers.

Any suggestions? Thanks. :-)

BTW, the grounds that I checked were the one near the alternator, the one off the battery to the chassis, one off the efi harness to the top of the engine near the plenum, and one near the starter. Any others that I need?




TL: DR; Nothing electrical in the truck comes on, despite having good battery and good main fuse.

Ship of Theseus

Ok....after a little more searching I did find this:

https://www.yotatech.com/forums/f116...-guide-194413/

I have some homework tomorrow....

MortonPhotographic

Check your grounds again. I made the mistake of assuming I had a good ground because I put new, heavy guage ground wire on my rebuild. I got a bad ground due to fresh paint on the block. I thought I has starter issues, but it was just a bad ground.

Make sure you have a ground (little to no resistance) on your block, not just at the wire itself.

Also make sure you have a good ground at the inner fender near the fuse box. I would even test for resistance at different points throughout the vehicle.

I nothing else, you can rule this out completely.

Hadmatt54

You have checked your grounds, so rule out the other easy things first. 12v batteries can be find today and short out tomorrow, they don't slowly fail they just fail, that's just their nature. Sounds like your battery might have failed! I know that you are getting 12.5 at the battery when you check it with a DC voltmeter, but if you compare a DC circuit to a garden hose the voltage is the pressure of the water, and amperage is the flow (amount) of water out of the hose. Your starter and accessories need that flow to function. A shorted battery will most always show good voltage until you put a load on it. Most auto parts stores are able to do a load test on your battery, many will do it for free, but a quick test is to put your voltmeter on the battery, watch the voltage and get a friend to turn the key to start. If your volt meter is digital the display may go blank for a second before it registers, if you have an analog volt meter you can watch the sweep hand drop when the load comes on the battery. If this happens then your battery has an internal short and needs to go to the recycle depot!

Ship of Theseus

I swapped the battery for a known good battery and the same result.

I had the idea that maybe my starter was arcing out inside and while reading the correct voltage at the battery it may be dropping the amperage. I replaced the starter (it needed it anyhow) and this did not help.

Terrys87

iTrader: (1)

Have you checked your inline fuse? It is the white wire coming off of the positive cable going to your fuse box.

Ship of Theseus

I get full voltage at the headlights and they don't turn on, to get the 12.5 volts there my inline fuse must be fine.

I am going to go over my grounds ONE more time....

my-4x4

I'd say use a test light on fuses and slowly work your way up to ur battery...I know how much of a pita it can be trying to found a faulty wire/ground/power....good luck

4Crawler

iTrader: (3)

Headlights get constant 12 volt power and are turned on by the headlight switch grounding the low or high beam filament. That ground point in the cab, behind the driver's side kick panel, large screw into the sheet metal w/ a bunch of ground wires running to it. Can't just look at a ground connection to say it is good or not. I find it best to unscrew the bolt, remove and wire brush the wire terminals and the sheet metal under the bolt and then reassemble. I had a bad ground there with my cruise control. It would periodically cut out after hitting a bump in the pavement. That ground wire from the cruise module must have been just a little loose or corroded and while it looked fine, that was the source of the problem. Also check that the ground wires are flexible up to the terminal connection, sometimes a wire will corrode under the insulation and still look intact, but the oxidized copper is very stiff and not a very good conductor of electricity.

And measuring resistance may or may not tell you what is going on. A digital meter only uses like a micro-amp of current to check resistance and most meters do not read very low resistances very accurately. So they might say 0.0 ohms, but there might be 0.5 ohms and try to run say 20 amps through 0.5 ohms and you have a 10 volt drop and 12.5 - 10 = 2.5 volts and that is not enough to make anything work. So a better test is to check voltages under load. Start at the battery posts and check voltage with key off and on. Then move to the ends of the + and - cables and keep working out towards the end of the circuit. If you all of a sudden see voltage go from 12.5 to something much lower, find out where the drop is.

navman93

Does the starter work when not engaged on the flywheel? No load test?

navman93

If you haven't figured it out, check starter relay. Other questions: Does it click when turn the key or make any noise at all from the starter?

HeadChopper

Hi, last week my 95 pickup 22re starting doing the same thing and i stuck at a gaz station after hearing that click comming from passenger side engine bay then no more electrical in the cab, so i check fuse and try replace relay then after about 5 min trying that he decide to start. I stop at my father house and then doing it again. After about same time trying playing with unknow issue, he start. Then on the road of my workplace i stop to buy bottle of water and then redoing it... the guys help me trying boosting my truck and it work after some try. Then i go work and after the truck does the same thing, so workmate boost me then he start and i return at my house. Next day i used my gilrfriend car but i try to start my truck just for fun and he start. Today my friend menician passed look at it and my truck start each time he try, like 30 - 40 time and after 4-5 time i try to let him reheat, didnt change...
Hummmm .... any help plz

navman93

your symptoms are COMPLETELY different from his...More info! Does it just click? The sound you hear from the passenger side IS the starter/solenoid.

Check battery voltage first, then remove the starter and do a no load test or take the starter to nearly any parts store for a check.

HeadChopper

sry but its EXACTLY the same thing .... when i start it, all shut off, no more light or anything working, then after like Ship of Theseus said ''cool-down'' period all electrical work and sometime he start and sometime i loose all power...

And its isnt my battery cause i crank my engine with sparkplug wire unplug to see if she keep turning the engine, and shes ok

hump85

I have an 85 pickup with a 22 re. I was driving in the rain for about two or three hours when all of a sudden, all the dash warning lights come on and the truck dies. I turn it over on the side of the highway and it turns over a couple of times but very weak then nothing. Tow it home. Try it the next day and the clock and some accessories work, but after some piddling nothing would work. I notice the black ground wire from this old looking jacobs ICM is shot to hell, burned and melted all the way down. So i am figuring that it shorted out and killed my truck.


With that being said, I have located where they cut the ignition switch wire to add the ICM. I tested the wire they cut coming from the factory ignitor and got a constant reading of .282 volts from that wire. I dont know if that is enough to do anything but i am waiting on a chilton manual in the mail. I am hoping that info is in there.

Also, I have tested the battery, main fuse, and all the fuses in the fuse box(with no load) on the passenger fender well. The main starter wire is getting the 12V from the battery. I cleaned the main ground to the battery and the ground on the passenger fender well to the ecu I believe and the accessories worked until I turned on the CB radio. I stopped right there and I have yet to see what it will do today. I am going to clean some more grounds, the one in the drivers kick panel and there is one by the ignitor and coil in the drivers fender.


Any help or suggestions would help would be appreciated. I am not that experienced with dc vehicle electricity besides some speakers subwoofers amps and lights in the past. I am trying to learn and try to fix it before I decide to haul it up to the shop and pay someone.


No one has used this thread since 08/11 so maybe someone see this. Thanks.

navman93

THe ICM operates at VERY low voltages, but if the INPUT voltage to it is too low it will not function correctly....If you can, without HACKING too much, supply the voltage to the input side with a 9 volt battery and see what the output is. If it is LOWER than what you had from the Ignition output (as stated .282), then chances are your input voltage is correct. I am an aircraft mechanic and use these methods a lot on Solid State devices and can usually isolate a bad part. If not....Try removing or disabling accessory systems one at a time and trying to start it, time consuming but proven. ....Let me know. BTW...If you use test voltages on equipment you ALWAYS want to use voltages BELOW the rated input to avoid destroying equipment. There is no more agrravating issue to have than having TWO failures causing a the discrepancy.

hump85

It turns out that the previous owner wasn't even using the aftermarket ICM. I should have unhooked it to start with but I thought they were starting the truck off it and if I had someone else look at it they would need to see what was going on. This was my first bad electrical problem and I learned some things from it but it turned out to be the simple and obvious. I unhooked the thing from the battery and tried starting it not expecting much but it turned over!!

That was that, I cleaned up all the wires that weren't running to anything and it has started and ran good every time so far.

hump85

Thanks navman

Xylus

I just went and looked at a truck for sale that the guy claimed runs but it would not start. It was doing the exact same thing as the original post in this form. When your turn the key the dash lights come on when you turn it to the start position you can hear the starter solenoid click then all the power goes out no dash lights or anything. Then if you wait abit it will do it again. While looking at the truck I tried jump starting it with my vehicle and tried discounting the battery cables from the battery terminal and hooking up jumper cables to rule out a bad battery did not fix it. It's the exact same issue sea of thesus was having. It didn't look like he found a fix in the form wondering if anyone else had this same issue? And found a fix?

4Crawler

iTrader: (3)

It could be the starter solenoid contacts or it could be the contacts in the ignition switch. You'll hear the click of the solenoid along with the circuit opening (CO) relay in the passenger side kick panel. But if the contacts in the solenoid are burned, they won't send any power to the starter and nothing will happen. Or if the ignition switch is weak, not enough current will flow to the starter solenoid coil to put it into the contacts, which in turn sends power to the starter motor. The CO relay will open while the starter is running to turn off some loads in the vehicle (like lights):
- https://www.4crawler.com/4x4/CheapTr...shtml#EasyTest
If either of those problems exist, jump starting often won't help as there is plenty of power at the starter but it's just not getting through the solenoid.