[semlin]

sure sounds like it, but just in case I'll see what mud thinks.

the bad alternator light came on suddenly today, along with the at overheat and oil lights. I stopped the truck and afterwards it turned over strongly but would not start. changed the efi relay for the spare and it made no difference. a while later it started but idled very poorly at about 450 rpm with the trouble lights off, but ran apparently normally. I limped it home where the lights came on again and it died across the street

I have checked all the connections and can find nothing bad. there is a small rad hose weep from the top rad hose close enough to the alternator for it to have sprayed there.

[Atoyot1031]

Did you check your voltage and amperage output?

[Atoyot1031]

Forgot to mention, last time I had an alternator go bad, it was obvious by the fact that the magic smoke managed to escape from it!

[semlin]

ok this is weird. the tranny shift lock is engaged so that I cannot take it out of park even with the brake pedal depressed and the ignition switched on. the only time that happened before was a problem with the trailer harness.

I was towing with the truck just before this happened and had just disconnected the trailer. maybe i had better remove the harness.

i have double checked and all fuses appear to be fine.

[semlin]

ok, perhaps it is a ground issue??

it seems I have no brake lights or tail lights and only one headlight, and the heater fan is permanently stuck on at a low level and does not respond to the fan control.

I have inspected all ground connections and they seem fine. I am going to clean and redo the body grounds but this is weird.

[yooper]

Does the 80 have fusible links? This sounds like a fusible link problem...

[semlin]

fusible links were fine, but I had to disconnect the positive battery terminal to check them. that solved the problem at least temporarily so I could drive home. when i reconnected the battery the old "disconnected" alarm armed. I think it is not as disconnected as the alarm store claimed. I looked under there and the brain is still in place

[semlin]

Originally Posted by CJF

You have not stated what your voltage is (as Atoyot1031 asked). Closer to 12 than 14, and/or no change with vehicle on/off (key "on") points to alternator, or at least a bad battery connection.

Curtis

my voltage meter is missing a probe so i cannot tell you the answer. as noted, though, somehow I have activated and armed an old alarm. after disconnecting the positive battery terminal to check the fusible links and then reconnecting it, the engine suddenly fired and the other noted issues with lights and fans were rectified. but when I did this the old alarm light also lit up and the arming sound came on. i drove it across the street home where it promptly stalled.

it might have been a bad connection, although the fact the starter cranked suggests otherwise, or it may be the alarm. I will remove the alarm tomorrow. tonight I was just glad to get it home.

[CJF]

How DARE you quote my deleted post!

Hang in there ,

Curtis

[semlin]

ok, update:

Does anyone have a 93 EWD and is willing to try to help me isolate some symptoms? My next step is to start taking the fusible link wiring loom off backwards from the battery and check for brakes. I was hoping to isolate it to a particular link and section of the loom based on the symptoms below.

I completely removed the alarm a while ago. I am confident there are no faults caused by the alarm wiring anymore. I have also cut out my trailer wiring harness and checked that there are no bare wires on the truck wiring. I was towing just before this started, and had just disconnected the harness (with the truck turned off), but that might be a coincidence.

since cutting out the alarm, the problem has come back, but not nearly as often and I have not had the harsher symptoms again (yet).

The engine has to get warm and I have to drive for a while for the problem to happen. I can fix the problem for a while by disconnecting the fusible links from the positive battery terminal.

after reading these two threads:

http://forum.ih8mud.com/80-series-te...me-help-2.html

http://forum.ih8mud.com/80-series-te...ery-issue.html

I think I have a wiring harness issue on the positive side or possibly a bad brain like grench did. I am wondering if anyone has the 1993 EWD and might be able to suggest where the fault would be to get these symptoms..

when it occurs, I have had (at various times) the following symptoms:

1. the alternator gauge red light comes on

2. the alternator gauge goes dead and centres

3. i get 3 dash trouble lights, AT, Oil and brake

4. no brake lights or tail lights

5. The dash heater fan gets permanently stuck "on" at a low level and does not respond to the fan control.

6. tranny shift lock engages even with the truck off and my foot on the brake

7. engine stalls

8. engine will turn over but not fire

9. engine may restart on its own after leaving it for a while, but when engine restarts idle revs are very low behaves as if the battery has been disconnected

10. engine will restart if you disconnect fusible links at the battery, wait and then reconnect.

symptoms 1-3 are more common and go together. They are completely intermittent and random and can last 5 seconds or 30 or stay on until you kill the motor. When they cease the alternator immediately shows it is fully charging.

I only had the other symptoms before I cut the alarm out. They might have been caused by the alarm or, as I now suspect, this problem simply went underground for a while??

all the connections at the alternator look fine. It had new brushes 20k ago. I can see no signs of contamination of the alternator and I have not gotten it wet lately. the battery and fusible link connections are also good. All of the fuses in the truck appear fine and I have swapped relays out.

I am also seeing the oil light alone coming on at random for short periods which may be unrelated. I have lots of oil and good oil pressure. The truck has always done this on a very very intermittent basis but now it is daily.

[cruiserdan]

I'm leaning toward where I pointed you.

[Beowulf]

Send a PM to TrickyT and point him to this thread. He has an amazing grasp of the EWD as it relates to the engine and charging circuits.

-B-

[cruiserdan]

Originally Posted by Beowulf

Send a PM to TrickyT and point him to this thread. He has an amazing grasp of the EWD as it relates to the engine and charging circuits.

-B-

That is a classic example of understatement.


The guy is brilliant......

[TrickyT]

Sheesh, talk about pressure to perform.

I do think the basic problem here is a bad electrical connection, either on the +12v side or possibly at one of the major ground points, but it's hard to say where without studying the EWD. One potential problem in trying to figure this out is that I've only got a '97 EWD but Simon's rig is a '93 and I'm not sure what the differences are. I'll have a look at my EWD when I get home tonight.

Simon, just to clarify: have you actually swapped out the the fusible links or have you just inspected/tested them? These are cheap, $10-$12 IRRC, and hence would be worthwhile to replace if you haven't done so already. Even if your old links are not the problem you can always keep them as a trail spare. Secondly, find a probe for your multimeter. This is almost surely going to come down to testing electrical circuits and you're going to need a functional multimeter for that.

More later.

[semlin]

thanks Tom,

i agree that the difference in years may be an issue but at least you have an EWD, and I do doubt that toyota messed with the engine bay wiring configuration much.

I have checked all the grounds in the engine bay and I have removed and cleaned the firewall ground. they all appear to be good.

[TrickyT]

Well this is definitely a weird one. Many but not all of the symptoms indicate a power supply-side problem. The lit alternator light and centering of the voltage gauge is a clear indication that the alternator is not producing any power. The inoperable stop lights, tail lights, tanny shift lock, inability to start, and rough running after starting all indicate to me that many of the circuits getting power from the "main" fusible link are dead or go dead intermittently. Charging of the battery also goes through this link. But so do the headlights, and you've never made mention of any problem with the headlights. So one key question: have any of your problems ever happened at night when the headlights were on and if so what symptom did they exhibit? If the headlights go out too, then it's definitely an indication of a problem with the main fusible link and/or the wiring from this link. If the headlights are unaffected, then I would carefully inspect the main power lug on the alternator, the one covered by the rubber boot. This was the source of the problem with Rory's truck (see http://forum.ih8mud.com/80-series-te...me-help-2.html for details). You may have to carefully strip back the insulation from this lug in order to inspect it. Any signs of discoloration of the wires or overheating of the insulation would be cause for suspicion.

The heater fan sticking on is a symptom in conflict with the ones above (from the perspective of the EWD), and I have a few questions about this. When the fan comes on, does the "low" LED indicator also come on, or is it just the fan motor without any LED indicators? Has the fan coming on occurred in combination with any of the other symptoms you list in post #10 and if so which one(s)? And when you say that the fan "does not respond to the fan control" do you mean that if you push the "hi" switch the fan won't speed up? The heater fan can only come on if the heater relay gets energized and there are only limited ways for this to happen. I'm still trying to figure out how this is tied in to the other symptoms above.

Lastly, the issue of symptom #3 - the three dash trouble lights: A/T over temperature, low oil level, and brake fluid level/parking brake. From your earlier posts it sounded like these could come on when you were just driving down the road. Is this true? Specifically I'm asking if these lights ever come on together when the transmission is in "D". A bulb check relay has to get energized for these lights to come on together and there's no power source to this relay when the tranny is in drive.

Ok, that's what I've got so far. More questions really than anything specific, but your answers will help eliminate possibilities. Oh yeah, it is most definitely NOT the ECU.

[semlin]

tom that is awesome. it makes more sense than you think

extra detail triggered by your comments:

1. i did initially think i had a headlight problem on one side. but since the problem remained even with everything else ok, i think it is a bad bulb. that side burns out bulbs very regularly.

2. the headlight switch on my truck is live with the ignition off

3. when the headlight switch is "on", even with the ignition off, the heater fan also works

4. when my truck was first imported into canada daytime running lights were retrofitted at the first and last garage i have taken the truck to. didn't think about it, but obviously they jumped some wires somewhere, and that jump may be connected to the symptoms above.

5. the daytime running lights are less bright than when i turn the lights on to low beam.

[semlin]

i am thinking i need to look for a DRL wire splice into my main fusible link connector to the alternator

[semlin]

ok the drl was accomplished by jumping directly from a wire (cut) going into the headlight relay in the engine bay fuse box to a black wire with an orange stripe (cut) that went into one of the two steering column plugs. I have cut out the jumper and reconnected at both ends to the original wires so hopefully that will eliminate some of the funny business. hopefully i don't get a ticket for having no DRLs.

[semlin]

and by funny business i hopefully mean these ones below. yes the heater fan would be on at a low level but the heater fan control buttons would not work, and yes the dash lights i mentioned would come on while i was driving in D. hopefully the mysterious black with orange wire somehow energized these puppies, but I am looking around some more under the dash for shenanigans.

Originally Posted by TrickyT

The heater fan sticking on is a symptom in conflict with the ones above (from the perspective of the EWD), and I have a few questions about this. When the fan comes on, does the "low" LED indicator also come on, or is it just the fan motor without any LED indicators? Has the fan coming on occurred in combination with any of the other symptoms you list in post #10 and if so which one(s)? And when you say that the fan "does not respond to the fan control" do you mean that if you push the "hi" switch the fan won't speed up? The heater fan can only come on if the heater relay gets energized and there are only limited ways for this to happen. I'm still trying to figure out how this is tied in to the other symptoms above.

Lastly, the issue of symptom #3 - the three dash trouble lights: A/T over temperature, low oil level, and brake fluid level/parking brake. From your earlier posts it sounded like these could come on when you were just driving down the road. Is this true? Specifically I'm asking if these lights ever come on together when the transmission is in "D". A bulb check relay has to get energized for these lights to come on together and there's no power source to this relay when the tranny is in drive.

[TrickyT]

Originally Posted by semlin

ok the drl was accomplished by jumping directly from a wire (cut) going into the headlight relay in the engine bay fuse box to a black wire with an orange stripe (cut) that went into one of the two steering column plugs. I have cut out the jumper and reconnected at both ends to the original wires so hopefully that will eliminate some of the funny business. hopefully i don't get a ticket for having no DRLs.

According to my EWD, the black-orange wire at the steering column connects to the headlight retainer relay. Depending on what terminal the extra wire connected to at the headlight relay, that could have effectively by-passed the retainer relay and caused your headlights to be live even when the ignition was off. Getting rid of the DRL and restoring the wiring to original form is certainly the right thing to do at this stage. At a minimum it will help us diagnose your problems. With the extra wire gone, do your headlights now behave like an OEM truck? Could there be other modifications to the wiring in your truck still present? If so, tell me about them.

Overall, I'm thinking this has got to be a wiring harness issue. I can't otherwise see any way for all the symptoms to be connected. I know you're in Canada and it's likely cold, but could you try pulling out the heater relay and driving for a while without it. It's in relay block #1, left kick panel. There should be no way the heater fan can come on then and I'd like to know if any of the other symptoms change when the relay is removed. The relay is certainly not the root cause of your problems, but removing it and seeing what symptoms change may provide additional clues.

Lastly, while you're under the steering column and inside the kick panel, look around for any signs that the harness as been rubbing against metal and perhaps has become frayed and bare wires exposed.

[semlin]

will do tom.

the kick panel would be where i just removed a whole boatload of alarm wiring.

[semlin]

so i got it all buttoned up, and reinstalled the battery. I have checked the wiring between the positive terminal the alternator and the engine bay fuse box pretty thoroughly. no signs of an issue.

everything seems ok but I still have daytime running lights which surprised the heck out of me. otoh, the heater fan no longer works when the headlight switch is on with the ignition off. i guess that is progress.

Tom if you are reading this, is there supposed to be a jumper on the headlight relay in the engine bay fuse box and, if so, between what contacts? I am pretty sure that must be the issue. it looked oem to me but i have had a good look around and can't figure what else is powering my headlights.

I will carry on tomorrow.

[IronYuppy]

Sounds like it's fixed, but if you want to borrow my EWDSM on short-notice I can send it over on Harbour Air tomorrow. Save you the trouble of buying/waiting for one from the USA if this problem persists. Mine is a '94 but they should be identical.

PM me if you want.

[semlin]

thanks for the offer morgan. you may have forgotten but i don't live in vancouver anymore. I am 250 miles east in the ok valley. harbour air doesn't fly here

looking at the diagrams in the FSM I can see the white jumper wire between two points on the headlight relay I was talking about so it is not gremlin free yet.

i still have drl and i don't know why the jumper wire i just removed was installed.

[IronYuppy]

Originally Posted by semlin

...ou may have forgotten but i don't live in vancouver anymore. ...

[semlin]

tom, explanation for the three dash lights -- it's a low charge warning

http://forum.ih8mud.com/80-series-te...se-lights.html

[TrickyT]

Originally Posted by semlin

so i got it all buttoned up, and reinstalled the battery. I have checked the wiring between the positive terminal the alternator and the engine bay fuse box pretty thoroughly. no signs of an issue.

everything seems ok but I still have daytime running lights which surprised the heck out of me. otoh, the heater fan no longer works when the headlight switch is on with the ignition off. i guess that is progress.

Tom if you are reading this, is there supposed to be a jumper on the headlight relay in the engine bay fuse box and, if so, between what contacts? I am pretty sure that must be the issue. it looked oem to me but i have had a good look around and can't figure what else is powering my headlights.

I will carry on tomorrow.

This is definitely progress. Do your headlights behave like in an OEM truck now? That is, do the lights automatically turn off when the driver's door is opened with the ignition turned off? If they do, then I bet the wire you removed yesterday was put there by someone who did not like that feature and added the extra wire to disable it. Makes me wonder what other things they did to the wiring on your truck.

As you pointed out in a later post, the headlight relay does indeed have a OEM jumper between two of its terminals.

[TrickyT]

Originally Posted by semlin

tom, explanation for the three dash lights -- it's a low charge warning

http://forum.ih8mud.com/80-series-te...se-lights.html

Yeah, I remember reading that post now. There's nothing in the EWD or Owner's Manual indicating that those three dash lights, in addition to the discharge warning light above the voltmeter, come on when there's a low voltage condition. The red light above the voltmeter is easy to see, and having all four come on together is confusing because you don't know what's really wrong. Since this behavior is not documented in the owner's manual and there's no circuitry in the EWD to explicitly activate the three lights in question when the alternator fails, I'm betting that this "feature" was not in the design specification. In other words, those three lights coming on when the alternator output drops was not intentionally built in by the Toyota engineers. They are suppose to come on for a few seconds whenever the ignition is turned to "start", but the relay that turns them on must get activated inadvertently via the ECU when part of the ECU loses power. Anyway, they do what they do and it's good to commit this behavior to memory for future reference.

So, back to your main problem. If we leave the heater fan out of the picture for the time being (it coming on may have been related to the wiring modification that you've now removed), then all the other symptoms indicate a loss of voltage for the circuits supplied by the "main" fusible link. There's a lot of key stuff running through this fusible link, including EFI, headlights, alternator, tail lights, stop lights, heater, and rear window defroster. Sounds like you've checked most of the engine bay wiring associated with this fusible link, but you should continue inspecting from the engine bay fuse block all the way to the interior fuse block. According to my EWD, this will be a large white wire. This wire goes through two splices in the engine bay, through a connector somewhere on the left fender, and through four splices in the interior (probably right near the fuse block). Check that connector at the left fender especially carefully, again looking for signs of overheating or discoloration of the wires and/or insulation.

If the problem re-occurs a good on-the-spot test would be to see if the headlights can be switched on and shine brightly when the alternator discharge warning light is on. The main EFI and headlight circuits are "upstream" (closer to the battery) than the alternator, tail lights and stop lights. So a failure of the last three without the headlights being affected would really narrow down where the wiring problem must be.

[semlin]

thanks Tom

to answer your question, when I kill the ignition with the headlight switch on, the headlight dies but the parking light stays on. when i open the driver door, the parking light goes off. In the past the headlights stayed on with the ignition off. so I guess the "mod" I just fixed had nothing to do with the DRLs, but was probably done by the PO.

the connectors in the fender all seem fine. I am looking again in the kickpanel or under the dash. my next step is to remove the dash fusebox and inspect behind for jumpers. I really want to figure out how the daytime running lights are rigged. i am thinking they must have moved factory wires to jump something somewhere because I can't find any more rogue wires.