92 Previa suddenly have no electrical

[boonietonton]

One day I was driving & suddenly all my interior electrical just died. I have no tail/brake lights, interior lights, radio, locks, windows, fan, clock, dash lights. Only things that work is headlights, signal lights, wipers, & horn. I checked all the fuses in the center dash & even changed the relay that's the main power & still nothing. I checked under the hood & checked the box next to the battery & all is good. The funny thing is I can turn on the A/C & the compressor comes on but the blower won't. I didn't change the big black relay under the dash & don't know how to check that. Could that be it or something else? I hope someone can help me figure this out. I can't drive it because now it's unsafe with no parking/brake lights. Thanks.

[timsrv]

When you checked the fusible link box on the + battery post, did you open it up to verify no corrosion inside? Even if all the fuses and links are okay they can still go bad inside (under the plastic). Take it off and remove the plastic to be sure (everything should be clean and shiny inside). The plastic cover is snap-on and can be removed if you release the little catches. Here's the inside a bad one with the cover off:

[boonietonton]

I will check that again. When I checked it last time, the 100amp blue fuse is stuck in the holder. I believe that's for ignition. I guess that's a sign of corrosion. but the other 2 came off easily. Wow. I didn't know this could knock out almost everything.

[timsrv]

All power to the vehicle passes through this block. It's divided up into multiple circuits. It only takes one to lose it's connection and you'll have problems. Not sure if this is your issue, but it's the most likely spot. You'll need to disconnect the entire box from the battery, then pull some extra slack on the cable so you can flip it over to work on it. There's little plastic hooks that will need to be manipulated to separate the plastic cover. A small screwdriver would probably work, but a metal pick set is very helpful for this kind of work. Tim

PS: If I remember correctly, the blue 100A fuse has the legs bolted from underneath. Box needs to be pulled and legs unbolted to replace that one. Probably not that one as it's there to protect your alternator. Tim

[boonietonton]

Here's a pic of my fuse box. What do you think?

20150319_175427[1].jpg

I hope it's just this that's causing the problem.

[timsrv]

That looks pristine. I would still use a voltmeter to verify power is passing through it, but by the looks of it I'd have to assume it's fine. Sorry about the wasted time in checking, but that's what troubleshooting is all about. Sometimes fuses and fusible links can fail but still look okay. Be sure to check continuity on those too.

With that many systems affected, this is most likely going to be a main circuit or relay that's failed. Does your van have a theft deterrent system?

[boonietonton]

No alarm. Just a plain jane van as far as I know. I asked around & someone told me it could be the blower relay. Sometimes the blower relay controls more than just a blower. That's the first I ever heard of that but who knows.

[timsrv]

The blower relay on the Previa just controls the blower. Get your test light and check the conductors on the back-side of your fuses (little metal nubs on the labeled side the fuse........each side of the number) for power (ground your test light to the chassis while you test). If no power, check again but this time ground your test light to the battery negative to verify same result. If you do get power to the fuses in both instances, then check for power at one of the items that's not working. Check with the test light grounded to the negative wire, the chassis, then the battery. If the test light illuminates when grounded to the battery, but not the chassis and/or the ground wire, then you have a bad ground. If that's the case, it's best to chase down the bad spot and repair, but sometimes it makes more sense to add a few extra grounds to the system. Having test leads with alligator clamps on both ends can be very helpful for establishing temporary grounds (for testing reasons).

If you find the grounds are good, but no power getting through the system, then it's just a matter of following the path of power backwards until you find where it's lost. The biggest challenge here is access. You may need to rip into your dash a bit. I'd also recommend pulling the fuse box up and disconnecting/inspecting all of the electrical plugs that go to it. You're looking for a connector or wire with burn marks on it. Good luck. Tim

[bluecrush]

I am having the exact same issue. The same accessories that were listed are not working for me. I have changed out the 100 A fusible link, and the 2 50 A fusible links at the + side of battery.

It all began as follows.

I purchased van about 1 month ago, so I don't know any history, 1992 Previa LE Canada dual moon/sun roof.

While driving and using A/C, fan on high, clock, radio the interior power would be fine.

However, when I would be stopped at a red light, the fan would stop for a quick moment, then come back on, as well clock would be reset and radio presets would be erased.

This happened a number of times. Things would be fine while vehicle was in motion, but when idle at red light and using accessories, quick power loss.

The other day, I had van in drive way at idle, and I purposely drew a lot of power, fan on high, A/C, clock, radio, head lights, hazard lights, rear defrost, then when I finally turned on factory fog lights, POP, loss of power. Only this time, interior power will not come back on.

I have no radio, dash/console lights, power locks/windows, brake lights, fan, dome lights

However, wipers front/rear, head lights, power mirrors, cigarette lighter, signals/hazards, all work, and van starts with no issue.

I checked battery it is at 12.41 and is also getting charged at 14.41.

All the mini fuses in dash cluster appear to be OK from visual inspection, and the relays "click" when I move fan switch on and at high. (I have not pulled and done continuity test under power, but it seems odd if all relays would click, but not pass power.

Any input would be greatly appreciated.

I have the exact same issue as the original post.

[photocopy]

The blower relay on the Previa just controls the blower. Get your test light and check the conductors on the back-side of your fuses (little metal nubs on the labeled side the fuse........each side of the number) for power (ground your test light to the chassis while you test). If no power, check again but this time ground your test light to the battery negative to verify same result. If you do get power to the fuses in both instances, then check for power at one of the items that's not working. Check with the test light grounded to the negative wire, the chassis, then the battery. If the test light illuminates when grounded to the battery, but not the chassis and/or the ground wire, then you have a bad ground. If that's the case, it's best to chase down the bad spot and repair, but sometimes it makes more sense to add a few extra grounds to the system. Having test leads with alligator clamps on both ends can be very helpful for establishing temporary grounds (for testing reasons).

If you find the grounds are good, but no power getting through the system, then it's just a matter of following the path of power backwards until you find where it's lost. The biggest challenge here is access. You may need to rip into your dash a bit. I'd also recommend pulling the fuse box up and disconnecting/inspecting all of the electrical plugs that go to it. You're looking for a connector or wire with burn marks on it. Good luck. Tim

+1 to this. On my previa I have had to replace the fusible link box as well as some of the wiring feeding it. If you have access to the shop manual, photocopy the 3 or so pages of electrical diagram and figure out where your problem circuits are and trace them in both directions, use a highliter to mark each one once checked. Often with this type of problem you can find a common point between all your circuits and this is where your problem will be,

Cheers
Matt

[moth]

My story sounds a lot like Bluecrush's:

I recently got a 91 Previa with about 293,000 miles on it. Mechanically, it's in great shape. It has a growing cluster of issues that I suspect are all tied back to electrical issues and I wanted to get your feedback.

When I purchased it, the owner admitted that the air conditioning didn't work and that there was an issue with the temperature gauge. When the AC was turned on, the switch would light up, but I did not hear anything to suggest a compressor was running or anything electrical was actually happening. The temperature gauge would start in cold, and then within about two minutes, the needle would shoot up to its highest position. Every once in a while, after running for a little bit, it would bounce back to the correct position. No actual issue with the engine overheating. Other suspicious electrical things would happen - it has an aftermarket stereo where the LCD display would grow dimmer and dimmer and then disappear after five minutes; a couple times, a power window would refuse to go up until the van was restarted.

Foolishly, I pushed the electrical system the other day, putting in a 100W power inverter, turning it on, and successfully running a typewriter, of all things. Since then, things have been worse: the interior fan is no longer blowing, the light on the AC switch doesn't light up. No previous issues with the blower, and it hadn't sounded like it was failing. Curiously, for a little while, the temperature gauge worked much more accurately, and the radio LCD was bright and stayed that way for an extended period of time. Those two things have gone back to their wicked ways and once again aren't at their best.

The fuses I checked looked fine. Battery is fine. Starts up OK, other electricals are fine. It feels to me like everything is tied to electrical issues - partially like the system isn't pushing enough amps, and now like the circuit for the fan / AC is non-functional. I'll have my mechanic check the fusible box. Does this suggest anything else they should look into while they're poking around with a multimeter? Sadly I have neither the space to work on this nor the skill to feel confident I could get things back together once I start digging.

Thanks!

[bluecrush]

OK, sometime ago I figured out the problem and made a quick youtube video. Follow the youtube link and I described what the issue is. It is a corroded/melted connector. Have a look and hopefully it will help you get things back on track. Since I cut out the bad connector and connected the wires, I have had no issues.

https://www.youtube.com/watch?v=OzrqKno_bVI

I hope this helps, because I had a real difficult time finding this issue.

Cheers!

[Previamanvan]

OK, sometime ago I figured out the problem and made a quick youtube video. Follow the youtube link and I described what the issue is. It is a corroded/melted connector. Have a look and hopefully it will help you get things back on track. Since I cut out the bad connector and connected the wires, I have had no issues.

https://www.youtube.com/watch?v=OzrqKno_bVI

I hope this helps, because I had a real difficult time finding this issue.

Cheers!

Hey guys! This is my first post. This forum seems really great and I'm very excited to be part of the community. I'm in the process of buying a 92 LE model with the dual sunroof. Noticed on the test drive that the interior lights, clock, and a few other things weren't working. Didn't get a chance to check the brake lights. I'll be checking that link in this very helpful video once it's mine. Wanted to see what the part numbers are for the connectors though. Can't really find info on that anywhere. Any help is appreciated. Thanks!