1990 b350 MESS of probs


Lukewarm256
05-06-2009, 03:23 AM
looking for a solution here.. for multiple problems, all related.

bought the van for a temporary replacement. Got this b350, with a 5.9 and an automatic with overdrive, for cheap, but bought it knowing that it wouldnt charge the battery up.

went and bought it, took a new battery, and drove it the 30 miles home--battery stayed up enough to start and run it just fine--but was low. took it out, recharged it.. we drove it a week by doing that. THEN, did some research on the thing and found out that the voltage regularter was in the PCM, or what ever that's called (the black box @ the top of the engine bay). SO, not wanting to pay 420$ for a new one, we just left it as is.

untill one day, it wouldnt start. Nope, she just wouldnt start--crank all day and night, but no start.

Well, some one found me a new alternator in the mean time, and i put it in there, hopin it would just fix the charge problem, just incase.

and LO! the van started. ONCE. and would never start again.

got a wrecking yard alternator, and LO! it started!... once. and never again.

SO, i hotwired the alternator to the batery--thing started, ran (lights got brighter when reving, so, had to be careful) and drove. used it for about a week like this--pulling the alternator hot wire off when driving..

then, one day, hooked it up to start it, and.... nothing. abosolulty nothing. the ONLY thing that worked was the heater blower motor.

was stuck like that for ages... then, in an attempt to figure this out, got another alternator--and, wtf, it starts!! but now the ABS lights are on, and the oil pressure reads erraticly... shut it off, had to hot wire.. and then, on 3rd startup, it would crank, but there was no spark OR feul. hotwire to the coil turns on the feul injectors... it starts..

that's the only conditions it ran under for a month.. and now it's back to doing nothing at all.. except the heater blower, lol.

ideas? i figure it's probably a PCM, that costs 4 times more than i paid for the van... but is there any chance it isnt?

thanks, for reading my book of stupidity.

alloro
05-06-2009, 12:37 PM
On the firewall near the brake booster is an assembly with a pair of relays. One is the fuel pump relay and the other is the ASD relay. Replace the assembly and everything should work normal again.

Lukewarm256
05-07-2009, 12:29 AM
On the firewall near the brake booster is an assembly with a pair of relays. One is the fuel pump relay and the other is the ASD relay. Replace the assembly and everything should work normal again.

looking up the diagrams for this, this definatly looks like it could be my problem! i'd bet that half that relay went first, and killed the charging system, and eventually the other half went--prolly though the hotwireing.

will be a while before i can get around to this, but if the thread's still here, i'll let everyone know how it turned out.

Lukewarm256
05-16-2009, 11:40 PM
ok, on this van--there is no 'pair' of relays. there is one relay to the left of the brake booster, that is metal, that is probably the ignition relay. then there is one to the right, that i have no idea what it does, but replaced it anyway.

replaced 2 relays, but not the ignition one.

again, all that happens when i turn the ignition is that the heater fan comes on--there is no power going to ANYwhere else (i think the lights may still work).

the manual i have (chiltons?) says that there is supposed to be a yellow, red, drk blue and black wire going to the ASD relay. there is NO relay in that whole van with that combonation of colors. the onyl relay with a yellow and a red wire on it is the ignition relay, which has a yellow, red, and 2 browns. there is no relay, in the book, with that combonation of wires (even the ignition relay in the book is different--no red OR yellow on it)

SO, what do i do next?

edit:
checked the wires to the relays--the 2 relays that are plastic (there's one that's metal, and i'm 90% sure it's the ignition) have no power to them at all--key on, off, in start position--no power, ever) i can put a hot wire to the one by the brake booster, and get these results--the larbe blue wire, and the large red one, activiate the AC clutch. the large drak green one turns on my injectors. the other, does nothing. the connector on the passenger side of the car, has small blue wire (did nothing) large blue wire (AC clutch again) and another large blue wire--which turned on my ignition--it would crank with the key, but there was no feul, and no spark, AND, a small bown wire--made a dangerous sounding buzz in the engine bay, didnt find out what it was.

SO, what now? not getting power, except to the ignition relay, red wire--but since we have no power @ the key, it does nothing... (unless large blue is connected, then it cranks, with no feul or spark).

... HALP!

alloro
05-17-2009, 12:26 PM
If you're not getting power to the ignition switch then you need to inspect your fusible links to see if one (or more) has burnt out. They are in the wiring harness up around the brake booster. If they haven't been accessed before you will have to slit the tape that they're wrapped up in.

Lukewarm256
05-17-2009, 09:28 PM
If you're not getting power to the ignition switch then you need to inspect your fusible links to see if one (or more) has burnt out. They are in the wiring harness up around the brake booster. If they haven't been accessed before you will have to slit the tape that they're wrapped up in.

ok, i have found 2 links near the brake booster, one is a simple connection of a large black wire that pulls apart--when together, it's working. THEN, there's a connection with a red wire, and a black wire side by side. one is a ground, and one is hot--both pass through the link just fine.

is there another link, anywhere, that i can check?

and today i probed up to the ignition switch on the lower colum--the 2 wires that need to be hot are pink and red--the red one is DEAD. it's dead all the way back to the connector on the firewall.

SO, what i did was connect it direclty to the battery.. and now the ignition works fine--dash lights come on, radio even works, gauges are working, AND i can get it to turn over.

BUT, i still dont get the injectors to fire, AND i dont get spark. So, there is probably a connection somehwere i am missing...

so, right now, does anyoneknow where that red wire comes from? or why i dont get feul/spark? (can still hotwire the injectors to work from the relay, but the relay still isnt hot)

i just wish i didnt have a crap wiring diagram.

alloro
05-18-2009, 03:39 PM
Both the pink and red ignition wires go back to the same splice. They each have their own fusible link. So if the pink is hot and the red is dead, then you'll need to inspect the fusible link for the red wire ignition feed. There are no connectors for fusible links, they are an integrated piece of the wiring harness. If for example the wire is 12 gauge for the circuit, then the fusible link is only 20 gauge. Should a short occur in the circuit, the 20 gauge fusible link being smaller will act like a fuse and burn up first. It doesn't sound like you've found the fusible links yet.

http://usera.ImageCave.com/ydfah/vehicles/Fusible Links.jpg

Lukewarm256
05-18-2009, 10:21 PM
Both the pink and red ignition wires go back to the same splice. They each have their own fusible link. So if the pink is hot and the red is dead, then you'll need to inspect the fusible link for the red wire ignition feed. There are no connectors for fusible links, they are an integrated piece of the wiring harness. If for example the wire is 12 gauge for the circuit, then the fusible link is only 20 gauge. Should a short occur in the circuit, the 20 gauge fusible link being smaller will act like a fuse and burn up first. It doesn't sound like you've found the fusible links yet.


OK, i have torn out the harness from the battery to the middle of the car, there were a whole host of fusable links--all coming from the same wire, and one was blown. Repaired it, and now the ignition red wire works without the hotwire.

i still cant get any spark, or feul (the injector never fires).

any ideas to solve that? and are there fusable links anywhere else in the car that i need to find? remember, i did thave a charging problem, before all this started...

thanks in advance.

alloro
05-19-2009, 08:49 AM
Now that the fusible link is fixed you need to test the ASD (Ignition) relay to see if you get power at the output of it when the key is on. If you don't get 12v at the output, then test for power across the relay coil. If you have power the relay is no good, if you don't have power across the coil you could have a blown fuse still.

Oh and by the way, regarding that 2nd relay you were wondering about that is near the brake booster. That's the wide open throttle cut out relay. It kills power to the A/C compressor when you stomp on the gas to give you a little extra power.

Lukewarm256
05-19-2009, 06:46 PM
Now that the fusible link is fixed you need to test the ASD (Ignition) relay to see if you get power at the output of it when the key is on. If you don't get 12v at the output, then test for power across the relay coil. If you have power the relay is no good, if you don't have power across the coil you could have a blown fuse still.

Oh and by the way, regarding that 2nd relay you were wondering about that is near the brake booster. That's the wide open throttle cut out relay. It kills power to the A/C compressor when you stomp on the gas to give you a little extra power.


have tested the relay, and it's working as it is supposed to. i even tested it according to the manual, and it tested fine that way as well... SO, atleast for now i can rule out the ASD relay...

i've checked the fusable links right next to the one that was blown--there are probably 10 or more, and they all test as working properly. The fuses in the dash are all fine as well.

so, i'm still as stumped as ever. i have working ignition and dash lights. i can turn the key and it cranks over--but i never get feul out the injectors, or power to the coil when it cranks.

i can ground one of the relays and get voltage to the coil, and the injectors fire up--but there is still no spark, atleast that i can tell

so, are all the fusable links where i found the others, or could there be more some place else, like the engine wiring harness? is there a sensor in the 1990 that could have gone bad, that would cause this problem?

thanks again for your help

alloro
05-19-2009, 08:58 PM
The output of the ASD relay is what powers the injectors and the coil. So if neither of those are getting power, I don't see how the ASD relay can test okay. Unless you're testing the wrong relay.

Lukewarm256
05-19-2009, 09:30 PM
The output of the ASD relay is what powers the injectors and the coil. So if neither of those are getting power, I don't see how the ASD relay can test okay. Unless you're testing the wrong relay.

i tested it, as in, i took it out (new and old were done this way) and tested the termianls according the manual.. it was perfect..

in the car, i tested it, and with key off, the red wire is hot, none of the others are. there is a large blue wire, and a small blue wire that get hot, with the key in the on position (true with both relays).. the large green wire only shows voltage when you're cranking the engine (very low voltage, 0.18 according to the digital tester).. but that's the only time it's hot.

SO, i would assume that the relay is testing fine, if it's doing its job--right?

tis why i'm still lookin for something else...

alloro
05-19-2009, 10:48 PM
SO, i would assume that the relay is testing fine

No I don't think it is. According to what you wrote up in post #4, when you applied power to that large green wire your injectors powered up. That being the case, the relay is not energizing and making contact from the large red wire to the large green wire. If it were, the green wire would have 12 volts on it when the key was on.

Lukewarm256
05-20-2009, 01:38 AM
No I don't think it is. According to what you wrote up in post #4, when you applied power to that large green wire your injectors powered up. That being the case, the relay is not energizing and making contact from the large red wire to the large green wire. If it were, the green wire would have 12 volts on it when the key was on.

but i've moved beyond post # 4, and found that broken fusable link--which was the red wire to the ASD relay. my last post reflect what happens on that relay, since it's been fixed.

now, i have lights, dash lights, even have a buzzer for about 5-10 seconds when the key is turned to 'run'. if i try to start it, it will crank now--which it didnt used to. BUT, looking down the intake, there is no feul from the injectors, and there is no spark, or even current to the coil.

besides which, the ASD relay has been replaced with a new one--even though the old one wasnt bad. i've even tested the car with a 3rd relay from another van i have, and i get the same exact results.

SO, this is why i'm stuck.

alloro
05-20-2009, 02:02 AM
I understand that the relay itself is good. But what I'm questioning is if the relay is getting energized or not (12v across the coil terminals).

Lukewarm256
05-20-2009, 04:52 AM
I understand that the relay itself is good. But what I'm questioning is if the relay is getting energized or not (12v across the coil terminals).


understood.

well, from the relay, with key on, all but that large green wire is hot. when the key is shoved into the start position, and the engine cranks, the large green wire becomes hot (but very low voltage). SO, in the crank position, everything in the relay is hot.

now, when it is like this, there is still no voltage at the coil--none.

however, when i ground one of the wires on the relay (believe it to be the small green one) i CAN get voltage to the coil, but when i do, the injectors turn on full blast--if i crank the engine, there is no spark (even though the coil has voltage)... so it still wont start.

so, imho, the ASD relay is working, but something else down the line is not--either there are more fusible links in the harness than the 8 or so i found near the brake booster (one of which was repaired, and all of which now function)... OR there's a sensor problem, OR, the PCM is bad (which i cant afford to replace).

SO, from any of this, it give you an idea? because i'm compleatly stumped.

the next bet is to tear ALL the harnesses open, and go through it wire by wire.. and hope i catch something, because if i cant, it's going to be that 350$ PCM (which makes this 104k mile one ton get hauled to the wrecking yard).

alloro
05-20-2009, 08:00 AM
There are no other fusible links besides the ones you found.

From your last description it does sound like the PCM is not working right. It's the PCM which energizes the relay and also controls spark, both of which you are not getting. You can get a used PCM in the range of $100-$150 off the internet.

I'm going on a day long trip today so I won't be back on until sometime tonight.

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