rear window defrost retrofit

Hey Guys

My brother has a 1988 4Runner that did not come with a factory installed rear window defrost. He recently purchased a 1985 4Runner w/out engine to use as a parts car that in a stroke of luck does have the OE rear window defrost. We are trying to switch these windows out so that his 88 will have the rear defrost feature but are not sure if all the necessary wiring is in the harness that goes through the frame to the rear door.

The switch for the rear defrost is to the left of the steering wheel on the dash under the left side vent. We found that the switch harness coupler was in the dash of the 88 and were able to connect the switch from the 85 directly to the harness that way. However, we can't find the two wires that would connect to the rear window defrost grid on the 88. On the 85, they were black and red and simply came out through one of the rear harness forks. We have untaped the harness of the 88 but have not found it yet.

Originally, we were thinking that since most car manufacturers simply have a "one size fits all" harness we would be able to find the two wires that connect to the window grid itself inside the rear section of the 88 harness (inside the rear door) and be good to go. However, we're now wondering if that is really the case (nothing ever seems to be as easy as it theoretically should be). Any info?

Additionally, if the defrost grid wires are not already run through the wiring harness and we have to run our own new wires from the switch in the dash, we really don't know which wires to splice into. The Haynes manual schematic that we're trying to work from seems to be generic at best. For that matter, we're not even sure if there is any point in trying to use the wiring harness connector that is in the dash if we have to run our own wires. Any input you guys might have would be great. Thanks.

FORGET Haynes manuals when it comes to wiring I have discovered they are seriously flawed when it comes to the 4Runners.
Check at the door relay box.
This ensures the window is up before the wiper, washers or defrogger can be operated and also that the tailgate is closed before the window will roll out.
Check the wiring outputs from the relay box. Keep in mind that toyota used many different harnesses for the same year of vehicle depending on where it was shipped. Not sure if there was only one for the tailgate.

Do an internet search for the FSM Factory Service Manual for your year some one might have them posted online as they do for the 93 in the sticky at the top of this forum.

Warning you do not want to be able to energize the defogger when the window is inside the door!
Good Luck

Thanks for such quick input 4wheel. I wasn't counting on anyone responding so fast so we continued to plow into things after I posted. I ended up ripping the wiring harness on the 85 apart all the way through the rubber boot that accesses the left rear sidewell (where the jack and rear washer bag are stored). It turned out that there was another harness coupler in this area which got me to thinking that maybe the segment of wiring that ran from the dash (with its accompanying defrost switch harness connector) to the sidewell might be the "one size fits all" portion while the segment that ran from the sidewell into the rear door might be more specific for individual options (power locks, defrost, etc.). I believe this is what you were talking about when you said that Toyota made different harnesses for different applications. Turns out the hunch was right. When I compared the "dash to sidewell" harness section on each of the trucks they matched up perfectly. However, the "sidewell to door" harness sections were different on each truck. The ground wire for the defrost grid on the 85 harness was simply spliced into a larger guage ground and the power wire (red) travelled with the the rest of the wires through the rubber boot, into the sidewell and into the tailgate harness connector. The corresponding terminal on the "dash to sidewell" connector was connected to a black power wire. On the 88, this black power wire was in the "dash to sidewell" harness and attached to the harness connector but the corresponding slot on the "sidewell to door" harness was empty. Soooooo...

We cut the black wire free of the "dash to sidewell" connector and essentially made a jerry-rigged version of the 85 "sidewell to door" harness (we couldn't reuse the harness from the 85 since many of the wires were too brittle and some had even broken off). We spliced into the same ground wire as the 85 for the defrost grid ground and ran our own power wire from the clipped black wire straight to the defrost grid (bypassing the harness connectors entirely). We rewrapped the harness, put the door back together and tried it out. Initially, the light on the defrost toggle switch in the dash came on so I went back to the window to try to frost it up a bit in order to see if the grid was working (don't have a test light or ohmeter right now). Didn't seem to be doing anything so went back to turn the truck off and go borrow a light from a friend. However, before turning it off, I noticed that the light on the defrost switch toggle had gone off even though the switch was still in the "on" position. I checked the fuse and it's fine and that brings the story up to date. I'm taking a break from it for awhile. I'll check into some better diagrams and get that test light...let you know on further developments (hopefully they'll be good!).

Some switches have timers incorporated in them mine doesn't
Relay box?

Any Public Library in your area would have the Factory service manual,Haynes,Chiltons,Mitchells,Clymers,Bentley and Toyota repair books.

There is also free AutoZone service manuals at:

http://www1.autozone.com/servlet/UiBroker?ForwardPage=/az/repair_info/repair_guide/repair_guide.jsp

1985 Toyota 4-Runner/pickup Factory Service manual:

http://www.jasuza.com/1985toyotatruckfsm.pdf

1993 Toyota Pickup Service Manual:

http://personal.utulsa.edu/~nathan-buchanan/93fsm/

2003 (2001-2004) Toyota Tacoma Factory Service Manual:

http://fsm.afraid.org/
http://www.junglecode.com/toyota/tacoma/2003_fsm/
http://65.200.1.6/FSM/

FSM (factory service manual)can be acquired in several ways:

Toyota Material Distribution Center
750 West Victoria St
Rancho Dominguez/Compton,CA 90220-5538
USA
Ph:1-800-622-2033 (outside CA)(M-F: 7-5 PST)
Ph:1-800-443-7656 (inside CA)
Ph:1-310-818-4630 (in or outside CA)
Speak to Beverly or Deloris
http://techinfo.toyota.com/public/main/mdc.html
http://www.4crawler.com/4x4/FSM.shtml

1)buy a used one off e-bay
2)some Toyota dealerships may give you one or sell it for $10-20 (used) as most Toyota dealerships don't repair many old Toyotas and no longer need the service manual
3)some public libraries sell their old books as they are not in demand any longer
4)some free buy & sell classified papers,websites and bulletin boards may have some used ones for sale
5)some junk yards may have one laying around
6)some Toyota specialty garages may have one laying around and no longer use it as the vehicle may be too old and those mechanics probably have so much experience that they could publish their own factory service manual with corrections and "real world repair tips"
7)if someone has the FSM maybe they could scan all of the pages and post it on a site for all of us to download or view.

For scanned pages of factory service manuals for other engines:

http://www.brian894x4.com/Scannedmanual.html
http://home.swiftdsl.com.au/~scorp/surf/1KZ-TE.pdf
http://www.showmesome.info/hilux/info/manuals/1KZ-TE
http://surf.mactherapy.com/1KZ-TE.pdf
http://surf.mactherapy.com/parts/
http://www.spyderchat.com/1zzfe.pdf
http://files.matrixvibe.net/docs/1zzfe.pdf
http://landcruiser.free.fr/mans/
http://surf.mactherapy.com
http://www.turbosupras.com/pages/technical/tsrm.htm
http://www.lieblweb.com/tacoma/Mechanical/96TacomaDiagrams/index.htm
http://perso.wanadoo.fr/adherence.4x4/liens_techniques.htm
http://perso.wanadoo.fr/adherence.4x4/index.htm
http://www.asatraction4x4.cl/html/
http://www.toyotasurf.asn.au/techsite/downloads.htm
http://www.grubinski.com/grubinski/automotive/toyota.manuals/
http://www.carsoft.ru/files/4runner95di.exe
http://www.hotrodder.com/kwkride/tech.html
http://www.autoshop101.com/autoshop15.html
http://www.mtv411.com/sitemap.htm

Sidney® ™
Repairs tv's,vcr's,home/car audio out of my home
E-mail:sidneybek@yahoo.com
Dartmouth,Nova Scotia
Canada
1985 Toyota 4-Runner,solid front straight axle,factory cruise control,sunroof,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome bumper with 246 000 KM