Electrical failures in my '89 Camry (1 Viewer)

[marcfj60]

A couple days ago, I started the car to go home from work and noticed the stupid power seatbelt didn't come back and choke me. Then I noticed the climate control system would not turn on and upon further investigation discovered that the windows won't operate, the dash temp gauge won't indicate anything other than really cold (normal when the car is off), the rear window defroster won't come on, and I think the cig lighter won't heat up. I'm not sure, but the radiator fans may also not be coming on. However, if I manually dial the power seatbelts back a couple inches and then open the door, they still power forward to the full forward position.

What still works:
Car starts, runs and drives like normal
Radio is fine
Interior and Exterior lights all work
Hazard light system functions
Wipers work
Cruise control button lights up when I press it
Electric Door locks function
Speedo and fuel gauge work (no tach in this car)

I started checking fuses in both kick panels but haven't come up with anything. I also took the top off the fusible link on the battery terminal that has 3 large fuses in it and they all look ok. I took the top off the fuse/relay box in the engine bay and again found nothing obvious. I haven't had much time to really dig into this and am currently trying to figure out how to get a wiring diagram without having to order a FSM. Maybe if I see a diagram I'll be able to figure out what each of those systems has in common and more easily pinpoint the likely failure point.

Anybody got any ideas or suggestions? I want my 30 mpg commuter back.

 

[slimbuddha]

This might be a longshot, but maybe the battery? If you go to the toyota tech site, you can pay the $10, and get a day's access to the EWD, and download it all.

Ron

 

[marcfj60]

This might be a longshot, but maybe the battery? If you go to the toyota tech site, you can pay the $10, and get a day's access to the EWD, and download it all.

Ron

I was thinking I should check the battery and the alternator. I've had other weird failures in other vehicles that ended up being related to a bad alternator. Thanks for the advice on the Toyota Tech site.

 

[pappy]

I have a Haynes manual you can use. I think it has electrical drawings.

 

[marcfj60]

I have a Haynes manual you can use. I think it has electrical drawings.

Can you verify that it has wiring diagrams? I'll go buy my own if it has diagrams that cover my model. I've just been disappointed with the wiring diagrams in Haynes manuals in the past. The store won't let you unwrap the book unless you buy it. But then you cannot return the book if you've unwrapped it.

 

[marcfj60]

Still no luck figuring out what's wrong.

I did more investigating yesterday. Every fuse I can find checks out ok with a continuity tester. The alternator is putting out 14.6 V and I measure 14.5 across the battery terminals when it's running. With the car off, I get 12.6 V across the battery terminals. I even swapped a bunch of relays that had the same part number to see if the problems moved around but no such luck.

I think my next step is once I have a wiring diagram I'll start removing relay/fuse boxes from their mounting locations so I can begin probing the back sides of them with my multimeter. I need to know where the inoperable systems are getting their power from and specifically which fuses and relays operate what. Most of the relays and breakers in the kick panels are not labeled.

 

[Cruisergreg]

Check to see if you don't have one big ground that serves all those circuits that's bad.

 

[BionicCruiser]

did you replace the fuses for those circuits anyway? it never hurts to try a new fuse or at minimum switch some to see if the problem moves. i've seen electrical stuff have continuity until it gets a load on it, then break continuity. after that, Greg's ground idea is good too. try a jumper ground even if it looks good for the same reason above.

 

[marcfj60]

Thanks for the ideas. I did not try switching fuses around, just relays that had the same part number. I've got the fusible link disassemled and things still check out fine with that. I took the engine bay relay JB apart and will proceed with cleanin the grease off the bottom, checking wires/terminals and then regreasing with lithium grease. After that, I'm moving inside and will attempt to determine ground locations.

 

[marcfj60]

Solved the problem. It did turn out to be a burnt fuse that I had just missed during my first inspection.

I had purchased a one-day membership to the Toyota Technical Information System Website like Ron suggested and copied every PDF from the Wiring Diagrams section for a '90 Camry. 1990 is the oldest year in that system but my generation Camry went from '87 to '91 and I figured it'd be close enough.

I looked at the Power Windows section of the diagram and it suggested a few tests which helped me determine that I still had good ground but I was definitely not getting any power to the circuit. Then I noticed that every system which was malfunctioning had one particular fuse in common - a 7.5 Amp fuse labeled as "GAUGE". Its purpose seems to be to provide low current to the main power relays for all of the affected systems when the key is in the 'ON' position. I located that fuse and BINGO!

I'm glad to have that monkey off my back.

 

[Ruadhrigh]

Good job Marc.

and now you have the manuals for future issues

 

[evanz80]

Great - glad to hear that you're up and running. I know that you'll be happy to get it on the road again.

With the price of gas, our (4-cyl) '93 Camry has been getting driven a lot, but I am really enjoying our 2000 Celica. A typical fill-up will yield about 35 mpg. It's almost triple what the 80 series will do.

Enjoy your Camry!

Solved the problem. It did turn out to be a burnt fuse that I had just missed during my first inspection.

I had purchased a one-day membership to the Toyota Technical Information System Website like Ron suggested and copied every PDF from the Wiring Diagrams section for a '90 Camry. 1990 is the oldest year in that system but my generation Camry went from '87 to '91 and I figured it'd be close enough.

I looked at the Power Windows section of the diagram and it suggested a few tests which helped me determine that I still had good ground but I was definitely not getting any power to the circuit. Then I noticed that every system which was malfunctioning had one particular fuse in common - a 7.5 Amp fuse labeled as "GAUGE". Its purpose seems to be to provide low current to the main power relays for all of the affected systems when the key is in the 'ON' position. I located that fuse and BINGO!

I'm glad to have that monkey off my back.

 

[marcfj60]

Nevermind.

The car worked like it should during the morning drive but on the way home, as soon as I shifted out of PARK, the fuse blew. It even blew a 10 amp and 15 amp fuse. I made sure that the A/C was off, the door was closed and the power seatbelt had finished coming back so that there were no extra loads on the electrical system before I'd shift and blow the fuse.

On the bright side, at least now I know the failure point and have a pretty good idea of what system is causing the fuse to blow. My first suspicion is the switch connected to the shift lever that tells which lights on the dash to illuminate and also the computer which gear the transmission is supposed to be in. The transmission seems to work correctly because I can drive the car with no problems. I don't think the failing fuse is associated with the function of the transmission but rather just the switching and dash indication.

Since I now know which fuse it is I was able to replace it after it blew, roll all the windows down and let the seatbelt come back before shifting into gear and blowing the fuse again. I have no temperature gauge indication and was concerned that the cooling fans might also not function since they are tied into the A/C system, which is one of the systems that fails when the fuse blows. I was happy to discover after arriving home that the fans were running. Yesterday was just about the worst day to not have A/C and not know for certain if my cooling system was functioning correctly. To make things even hotter, I had the temperature lever for the climate controls pushed to the hottest setting just in case I needed the added cooling effect.

 

[evanz80]

Bummer! At least it sounds like you're isolating the problem. I agree with you - it's been hot. Not a good time to drive around with the heater cranked on high.

 

[DanS HJ-45]

Marc:

My pickup did something similar a while ago (the guage fuse would blow if the left turn signal was on at the same time the brake lights were activated). It came back to a poorly installed trailer wiring pigtail.

So I'd easily buy a problem in the wiring harness or switching for the dash indicator.

Good luck tracking it down! It took me forever to figure out what was blowing mine (because of course it seemed random when it would blow).

Sounds like a "fun" drive home. Cruising along yesterday with the heater on has got to be a memorable experience.

Dan

 

[marcfj60]

Thanks for the encouragement. I've officially decided I hate vehicles with automatic transmissions (if I have to work on them). It took me two hours to get the center console removed and get the mechanicals and switches exposed for me to start testing things out. The power seatbelts with retractors hidden below the storage box in the console complicated things but weren't that much trouble. The O/D switch located in the molded plastic handle of the shift lever is one of the worst designs I've ever seen. You cannot remove the rubber/plastic top of the shift lever until you've removed the two terminals for the O/D switch wires from the connector that's hidden under the console. And in order to be able to see the mechanism and wiring, you have to remove the cover, which requires the removal of the rubber top of the shift lever. What a PITA.

 

[alia176]

Sorry if this has been covered already but are all the light bulbs in the back working ok and not shorting out (maybe hard to tell visually)? Perhaps remove all brake and rev light bulbs and repeat the same actions that caused the fuses to blow and see what happens.

Just trying to start with the obvious stuff first...

 

[marcfj60]

Latest progress...

I disconnected the wires going to the back-up lights (and brake/parking lights in the same bundle). The fuse didn't blow when I shifted into Reverse. Unfortunately, close inspection of the wires, bulbs and sockets has not produced anything useful for solving this problem. They all seem to be fine, both from a visual and electrical continuity perspective. So I'm going to move down to the harness that goes up the trunk support since these lights are located on the back of the trunk lid. Maybe that thing got pinched or some wires got cut after 20 years of opening and closing the trunk. I'm going to also check the back-up switch on the transmission, if I can figure out where it is.

 

[SteveLCetc]

You could use an ohmmeter to check the disconnected wires for a round. You would at least know which one to look at then.

 

[marcfj60]

You could use an ohmmeter to check the disconnected wires for a round. You would at least know which one to look at then.

I'll assume you meant a ground. Good idea. I'll see if I can find something that's shorted to ground that should not normally be, or at least has less resistance than what seems reasonable. I took one of my blown fuses and dismantled it so I could have some terminals to clip to and plug into the fuse location. So I clipped one end of my mulitmeter to a terminal stuck in the 'load' side of the fuse and the other to a good ground. I noticed when I shift into Reverse that my resistance is only a few Ohms while shifted into any of the other positions the resistance is about 15 Ohms. I don't know if this is helpful to me but at least pointed me in the direction of the reverse switches, indicators or tail-lights. Hopefully it's not the wrong direction.