I am having electrical trouble with the headlights and tail lights in my '88 AllTrac. From what I have read, the 162's with the 3S-FE have the same fuse boxes as the 165's. I have narrowed my tail light problem to the fuse box in the driver's kick panel. Here is my thread on AllTrac.net where I have basically talked myself through troubleshooting. http://www.alltrac.net/phpBB2/viewtopic.php?f=22&t=43334 When I bought the car I was able to drive ~100 miles with no problems. Although I had none of the lights turned on, STOP lights weren't working as well. (Followed close by a friend, using hand signals) I was able to build a harness pulling the tail light relay off of the fuse box. I hard wired a switch to turn the tail lights on and off. Once my STOP and tail lights were working 'properly' I took the car for a test spin at night using the head lights. The passenger headlight was very dim compared to the driver side. It eventually went back to full brightness. After about 25 miles of spirited driving the battery started to die. Replaced the battery with a spare I brought along and headed back to the garage. Tonight I started checking for the headlight short. I started with the passenger headlight plug, testing the continuity. I got continuity on all three plugs. To me that's a good indication of a short. I pulled the fuse for that headlight and measured the continuity at the plug again. It read zero continuity on any of the plugs. That rules out the wiring between the lights and the fuse box. Pulling both fuses, I was getting continuity on one side of each relay plug. It is my understanding that these are power connections and should not show continuity to a ground. I then checked the continuity of the headlight relay. If my understanding of relays are correct, I should have continuity on one connector which is the ground. The rest should be open when there is no power to the system. I measured continuity on all four of the connections. Basically what would really help me out are the voltage and continuity measurements at the headlight and tail light relays. Apparently the guys on AllTrac.net don't have 10 minutes and a multimeter. Any other input is much appreciated.
Starting with the Taillight relay. You will get continuity to ground on pin 2 which goes out to the lights. Pins 4 and 3 go to the fuse and pin 1 goes to the switch assembly. You should only get continuity to ground on pin 1 when the switch is on. The headlights switch almost the same except pin 5 goes out the headlights. Check the ground on the relay block on the drivers side kick panel. Honestly, I wouldnt be too worried about a continuity check as I would just using a voltmeter. If you have a short, chances are you should be blowing a fuse. Check the voltage at the fuse panel. With the car running it should read somewhere around 13.4-13.8V. Turn all your lights on then start going down the line with the voltmeter. There should be very little voltage drop from the fuse panel at the plug of the lights. No more than .2V loss. If its more than that, Id start checking for corroded wires or connectors. A wire or wires may have got nicked and they are corroding from the inside out. Which will be a PITA to find.
I realized tonight that continuity isn't a good test for the problem. I'm going to pick up a test light tomorrow and poke around. If all else fails I will begin creating an entirely new electrical harness. That would be my best bet since there could potentially be even more electrical problems down the road. This 24 year old wiring seems pretty brittle. It would also give me a full understanding of the electrical system as well as allow me to relocate the fuse boxes to more accessible locations. Even though it's a project car, any Celica fan would understand me wanting to get this thing reliable and back on the road ASAP.
Dont waste your money on a Test Light. Get yourself a good DVM (Digital Volt Meter). Fluke and Wavetek are good brands...stay away from the ones at Harbor Freight and the like. That will be more useful than a test light. Test lights are nice for quick indications, but the problem with them is that they complete circuits in times they shouldnt. So if you start probing around with a test light in places you shouldnt or by accident you can toast something.:angelsad2 Where as a DVM wont hurt anything by probing around.
So it seems that the alternator isn't charging the system at all anymore. At this point I have decided to start pulling the chassis harness and start rewiring. Today at work I found a couple pdf's with all the stock Toyota pin and connector types with the part numbers. Before I begin I just have a few questions. It is my understanding that the chassis harness and the engine harness are separate, although they do share connections on the fuse boxes in the engine bay. Is this correct? It seems that the A/C is a part of the chassis harness with the front lights that runs across the front of the engine bay. Is this correct? Last, are the fuse boxes able to be refurbished? Once I disconnect all the relays, fuses and connectors will i be able to check all the connections within? I'm about to have 32 days off work, so I'll have plenty of time to do this right. If it takes me that long to make a harness there's something seriously wrong. Haha. I figure I can get another 24 years out of this car with a proper rewire. I'll be sure to start a project thread that will have tons of good info.
So the battery not charging wasn't a clue! Yes, there are 2 seperate harnesses No - it is part of the engine (block) side harness as is the Alternator wiring, the above answer is correct but you will have to splice out these wires. You can check connections just by inserting a meter? If you can, I'd suggest dipping the fuse holders/relay contacts in vinegar to clean the contacts Start at the battery and work your way back, sounds like the alt charge wires/connection are damaged for a start (check the head harness for chafing as well) I'd simplify things and take pics of the sections I need info on - eg. just highlight the pins in the pics and specify if you mean continuity to ground or between pins?
Thanks for the info! I had originally driven the car 100+ miles when I first bought it. Although I didn't use any lights whatsoever. So the alternator was charging at that point. Something went wrong driving with the lights on. As far as tracing the short, that's not going to happen as of now. I already have the front half the harness out of the car. It's going up on stands tonight so I can take the fender off to remove the rest of the harness.
I've hit a road block with the orange grommet in the inner fender that houses the harness and goes into the cabin. Is there a trick to remove this or is an x-acto blade in order?
yeah you have to remove the grommet with the harness, the electrical tape wrapped around the harness holds the grommet in place really well So from the inside of the car squeeze 2 oposing edges of the grommet together and push the grommet forward through the hole You'll also have to remove or at least disconnect the hood release cable as it goes through the grommet to but it is not taped in place so you can pull the hood release cable through the grommet
The rubber grommet looks more like a funnel with a long tube indicated by the red line which is securely taped to the wiring harness which is why you can't just pull the harness through the grommet. So like I said before (green arrows) from the inside of the car squeeze 2 oposing edges of the grommet together and push the grommet forward through the hole Now is a good time to add any extra wiring going to the engine bay as their is an unused nipple (yellow arrow)
I ended up just using a screwdriver to pry it far enough to get another screwdriver in there. Then I kept alternating the screwdrivers till half of the grommet came out then just pulled it the rest of the way. There was no way i was going to be able to get to it from the inside. Fuse box and the firewall padding were in the way. I removed the Fuse and Relay Box No. 2 from the engine bay this morning. There are several spots that have been melted. I guess I'm going to have to source another one. How do these things open up so I can check out what's inside?
What voltages should I be getting at the tail light relay when the headlight switch is turned on all the way?
This is where my thread on Alltrac.net died. I honestly don't understand why it is so hard to give this information.
if i had a multimeter i could help you. it's the one thing i've been able to get away with not having. i'm sure someone will find out for you.
ok, heres an idea, see the point that is marked with no voltage, get a continuity tester and jump that to the pins on the pin out and make sure the wire isnt broke, then tell us what pin it is and we can go from there with wiring. also show us which pin out is the 5.8v reading your getting so its like this...
