Hey guys I'm at it again ... I got the 87 4runner home just in time 4the wife's bday. Anyways I have a few issues.
1st: The BRAKE LIGHT ON DASH CLUSTER IS ON(it gets brighter when E-brake handle is pulled to engage E-brake. I drove 4Runner 30 miles from my dads & the mastercylinder is dying or dead. Would that make the light go on?

2nd: The charge light on the dash is on but my battery gauge is reading about 13-15 about 3/4 of the way to the 18. My dad showed me how to see if ur alternator is working by touching the back of the alternator w/ a wrench 2see if it is pulling & it is not. So any advice?

3rd: my check engine light is on as well, would any of the above cause it to go on?

4th: I cannot get my back window down any electronic advice? Places to start looking. I hear a click like from a starter w/ a bad connection .... ok we'll thanks guys I've had a 4runner b4 i did a tailgate transplant but everything worked. Also I dnt know all the components.

 

1. Brake light alone. Low fluid. With charge light. Alternator or charging issue.

2. Rebuild.

3. CEL. Pull codes. 4crawler.com

4. Search Rear window 4crawler.com

:wabbit2:

 

Agreed on all points. Best bet alternator for charge/brake light.

 

So yesterday my 4x4 tercel wagon's alternator died & the charge & brake light came on lol. So I'm pretty sure that's my issue on the 4Runner. Also my radiator developed a 7inch crack so that was yesterday was great!! The fluid in the mastercylinder was low but I filled it b4 I posted issues.

 

Ok so I started in on the rear window on the wife's 87. The motor works & regulator works good. I do not have a rear window whipper arm but the rest is there, is it possible that since I don't have an arm its not retracing 4 the sensor to know so that is y the rear window wont roll down by switch ? The relay box clicks..... also in order to get the window to roll down I pulled the tailgate panel to tap in to the motor harness & I saw the cable to the handle is not pulling the passenger side tailgate clicker.(little actuation) so maybe the tailgate thinks its still open & won't let window down ?? I'm a little lost but I had a 88&89(the 89 was a 84-88 style) w/ the 3.sl0w the tailgates were hammered but I got 1 to work with all the parts from the 89 thanks 4 all ur input & keepin up withwhat I am doing.

 

Hi mikeztoyz,
Yes, IF no relay clicks, possible that relay logic thinks door is not all the way down OR wiper is not in its park position. Gotta lok physically at wiper park sensor.
Relay clicking suggests that relay logic says it is OK to turn on motor. However, relay contacts may be oxidized so they do not allow current to flow to motor. Some people (Chefyota, and Terry87 I think) have issues with this, especially if you had taken top off and exposed relay to elements.

I posted location, schematic, notes and a couple of pin-outs for rear window control relay module on my build page here:
Control For Rear Window From Rear Deck
Hope that helps.

 

Hi guys,
Rather than starting another thread, I think the community prefers that I replied to closely-related one so... After de-greasing my engine, my charge and brake lights came on and are staying on. Trucks runs fine.

My printed schematic:


Close-up of Alternator pin-outs:


Did a few checks:
Field Excitation, IG pin:
12V (in red) from ENG fuse is good.

Alt charging output, Pin B (blue in schematic):
12.33V (seems normal) when Ign ON and Engine OFF
Healthy 14.4V when engine running

Charge Light Output, Pin L (yellow in schem):
Ignition OFF: 7.29V
Ignition ON, engine OFF: 1.7 V
Ignition ON, engine ON: 1.7 V

When Charge light output "L" goes significantly lower than 12V provides negative potential to charge light and also brake warning lights.

This is where I believe the issue is.
It does not look like a short because I have 7.9V when ignition off, although I still need to trace where the 7.29V is supposed to come from.
It seems like something is pulling voltage down to ground when IGN is turned on. Could it be the yellow wire from emission control comp?
Could it be an internal issue with starter electronics?

Either way, I think "L" should also output 12V when alternator is working properly.

May I ask you guys with healthy charging system on 1986 - 1988 4Runners to verify/see what you read
At output "L":

• Ignition OFF
• Ignition ON, Engine OFF
• Engine running

Also Output B Engine running


Convenient access/test points here:



Thanks a lot in advance. I will post final solution on my build thread and provide link to it.

 

I changed 3 ECUs,1 is new from auto zone.Still check engine light stays on when running and it wont let me retrieve codes.I hope im doing this right,do not know how to post a problem or get back here to get answers.Please help.3 months I have this trouble and hours of searching/Parts changed.Thank you

 

1987 runner,Check engine light stays on while running.Can't retrieve codes,Put jumper in ,Key on ,light stays lit..got new ECU Auto Zone,Same thing but that ecu runs truck like crap.(dorman?)1990 and 1988 ecu runs great but CEL stays on and cant pull code.Hope im doing this right(post) but really could use help after 3 months of searching.Thank you ,my email desertraider@gmail.com Thank you

 

You should make a new thread for your problem, this thread is from 2012. If reading the codes doesn't work, first thing I'd look at is shotty wiring/repairs/broken wires before I'd blame the ECU. I don't have a wire diagram for an 88, so I can't advice which wires to test where, but it should run to the ECU connectors.

 

Yes i've been looking short broken wires.The New ecu wont run the Buggy but the other 2 are original Toyotas and run pretty good,Thank you I will keep searching...So go to threads and title 1987 check engine light ?Im not sure how to do a thread.But will try.Do you have a suggestion for the title?Thank you again.73s.

 

To create a new thread, click on this link for the 1986-1995 Trucks and 4Runners forums section: https://www.yotatech.com/forums/f116/

Once you get to that page, click on the button "New Thread".

You can title it something like "1987 4Runner Check Engine Light on, cannot retrieve codes" or something like that.

 

I will thank you for your patients and Happy Toyota trails to you.