Ok, I started a quick tune up on the 22rec 87 4Runner. Recharged the K&N, changed oil/filter, new plugs/wires/cap/rotor, replaced thermostat housing seal. Within a mile of the house, the gauge cluster (oil preasure/water temp/volts/tach) all went dead, speed and gas still worked. I changed the blown 7.5a fuse in the kick panel and within a mile after working again, it blew again....

Is there something common that would cause this fuse to blow that I would have messed with during the half tune up? Didnt have time to get to the valves or timing. Why is it working in the drive way and then blowing driving away? Chasis ground, engine ground are solid. I first thought it was my corroded pos terminal to fuse box wire and upgraded to 4ga store bought, but still blew the second time after "working" in the driveway.
Im not an elecrical guy, help?

 

According to the '87 FSM, the 15A engine fuse controls the "Combination Meter"

 

So after driving it and parking it over night, came out to go to work and the battery was dead. So definitely have a short somewhere. Where would this be right after doing a tune up?

 

Still need help? Anyone?

 

Hard to say as I have never had an issue like that and who knows what you may have bumped during your tune up

 

Ok, so after normal tune up, d/s kick panel fuse 'engine' blew. I replaced it, and a badly corroded main ground to 80A fuse batt cable with bigger gauge terminal wire. The 'engine' fuse blew again. Still driveable but: turn signals, tach, voltmeter, temp, and oil pressure didnt work. As I drove, batt seamed to be draining as engine was getting little rough and lights dimming. Next morning batt was dead. Charged battery and sat a couple days, battery dead.

I took off the neg battery cable and used a test light from neg cable to neg terminal and got a light. So there is a short somewhere.

I pulled the AM1 40A and the light went out. I pulled all other fuses I could find and the light went out when I pulled the 7.5a Ignition fuse on d/s kick box. Then I unplugged anything I could think of that was ignition related no change, until I pulled a connector with one red in and one red wire out around the cruise control computer area, then the light goes out. So whatever that wire is is the short. Does anyone know what it is. It does "seem" to be newer maybe, so there is a chance it has to do with the alarm. Any ideas?

 

Encircled in yellow looks like connection to door open switch.
Sorry using smartphone where internet is spotty, so hard to look at schenatics.

 

"so there is a chance it has to do with the alarm" ! Well, there's yer problem, lady.

The LH door open switch (according to my '93 EWD) is all red. It grounds with door open (and it should turn on the dome light, etc.) Use your multimeter to see if that wire grounds with door open, and not with door closed. You might as well look for battery voltage on the other half of the wire (with key-on). But my EWD says it's powered by the DOME fuse,

If you have an aftermarket alarm, who knows where they picked up power, that might be going through the door switch. But try the tests above.

The ignition fuse (in '93) powers only the ALT light (and cruise control). (Hey, I don't make up the names.) While I'm not certain, shorting the yellow wire (to ground) at the alternator could take out the alternator output (allowing the battery to just discharge as you drive). It should also light the alt light, but I doubt that takes enough power to drain the battery overnight.

 

Yeah, i unplugged both courtesy door wires and with both doors closed and the ignition completely off, i get no light using a test light from the battery ground cable to the neg terminal. So no short should be energizing anything.?.

The second I turn the ignition to accessory it blows the engine fuse. It will still start and run but the battery only discharges.

 

A test light is good, but a multimeter is so much more powerful. Here, you can test whether there is short to ground (you can do that with a test light, but it's a pain). You've got a charging problem; a test light won't give you the answers you need. Multimeters aren't expensive (any more) https://www.harborfreight.com/7-func...ter-63759.html

 

Yes, I have a multi meter, I get power to the door switch with everything off but I'm suppose to. Turns out my door wasnt closed for that test so i was getting a circuit.

So something is shorting and giving too much amps on the "engine" fuse circuit. Everytime I turn to accessory it blows the "engine" fuse and the battery wont charge.

All I have is a Hayes manuel and Im not an electrical guy, doesnt help much.

 

With the truck running im getting 14 to 15v at the fuses. Do i have a regulator issue? Is that attached to the alternator?

 

Ok, so found a thread all of a sudden that hadnt come up the last 900 times i searched. Guys had same fuse blowing issues. Turns out it seems to be the reverse light wires were sitting on the exhaust pipe and melted through. Pulled them off the pipe and separated the wires, put in what must be the 20th 15a fuse, and started up and seems to be charging.

So now the issue is where do you get a new reverse sensor connector wire? Does it come as one piece?