Vladislav Posted August 27 Share Posted August 27 This may also not work for '89 truck. Starting from somewhere about 1991 wiring in a RD became all made by wires in white insulation. With tiny black scripts (or marks?) on each one. Not multicolored harnesses as "88 and earlier models were made. IDK if the particulat schematic is identical or not but that doesn't seem be of a must. And sure work with wiring all of one color isn't a big pleasure. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557714 Share on other sites More sharing options...
Joey Mack Posted August 27 Share Posted August 27 I have some hand writen notes from an '87 RW that I did a lot of wire repair and terminal bars.. I will post pictures shortly.. Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557718 Share on other sites More sharing options...
Joey Mack Posted August 27 Share Posted August 27 https://photos.app.goo.gl/CtHebLjzJxNeu6RN7.. I dont think this is what you were asking for, however, it's free '87 Superliner. 'R' cab.. the model and v.i.n. is there in case you need to look for info common to 'R' and 'RW'.... I have so many note books from my repairs, that I pull my hair out trying to remeber which box they are in.. I have recorded 23 years of jobs in note books.. I guess back then I was doing it to post info today to help guys like you.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557720 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 Ok I ran a new power wire to the washer switch and now the pump works. im dead in the water on what to do with the high beam though. Head lights come on and the dimmer switch has power to it but I can’t get the head lights to change any suggestions? Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557991 Share on other sites More sharing options...
Joey Mack Posted September 3 Share Posted September 3 bad dimmer switch? are the wires inside of a plug or just have female blade connectors on them and plugged into the dimmer? Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557992 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 (edited) I clicked the link Joey but nothing comes up Edited September 3 by Supahonky Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557993 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 The dimmer switch was bad I replaced it but I still have nothing. It’s the original connector 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557994 Share on other sites More sharing options...
Joey Mack Posted September 3 Share Posted September 3 sorry bud,, I have had an issue with pics for months.. Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557995 Share on other sites More sharing options...
Joey Mack Posted September 3 Share Posted September 3 dont you have terminal strips under the hood for the lights and the horn? Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557996 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 Looks like a harness comes out of fire wall splits into two harness and leads to a bus next to each headlight Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557998 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 And one of this harness does connect to the bus on the firewall Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-557999 Share on other sites More sharing options...
Joey Mack Posted September 3 Share Posted September 3 the wires are coming from the terminal strip on the firewall left of the steering shaft. they are 14 or 15 pin strips. Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558001 Share on other sites More sharing options...
Joey Mack Posted September 3 Share Posted September 3 i bet the wires are wrapped in that hard plastic woven loom. If there is good power coming from the dimmer switch, I bet there is a bad wire or 2 in the loom. probably nice and green.. does the harness run by the steering box and go to the left hood hinge area? Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558002 Share on other sites More sharing options...
Joey Mack Posted September 3 Share Posted September 3 in my note book, pin #8 on the left terminal strip on the firewall, is the headlight power, but for some reason I didnt write down which was high beam. I'm also missing a note book from an RW that I re-wired... It had better notes.. wish I had more for you. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558005 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 So there is a harness that has brown and yellow (same on the dimmer) it shares another harness in the same loom that is a bunch of greens I think it piggy backs to the other headlight. If I disconnect I either lights got out. The green connects to bus next to steering shaft that is 10-14 Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558006 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 Yeah I checked there for breaks the hinge area Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558007 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 I noticed someone added a side marker onto the dimmer on the buss nest to the headlight could that be interfering with it? Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558008 Share on other sites More sharing options...
JoeH Posted September 3 Share Posted September 3 54 minutes ago, Supahonky said: I noticed someone added a side marker onto the dimmer on the buss nest to the headlight could that be interfering with it? Headlight hi/lo beam switch should be a button on the floor, for your left foot to push. Is this the dimmer switch you're referring to or are you talking about the dash mounted interior lights dimmer?... Just want to make sure we're talking about the right switches here. Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558012 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 Headlight high low mounted to the floor Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558020 Share on other sites More sharing options...
Brocky Posted September 3 Share Posted September 3 Those floor mounted dimmer switches tend to collect dirt and water and corrode back up the wires a long ways as well as the plug corrodes.. Quote Brocky Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558022 Share on other sites More sharing options...
Supahonky Posted September 3 Author Share Posted September 3 Yeah I sprayed some terminal cleaner and scrapped it around with a pick Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558024 Share on other sites More sharing options...
Supahonky Posted September 4 Author Share Posted September 4 Ok more info the headlight/parking light switch first pic seems to turn the headlights on in either position the second switch on top of the dash seems to do nothing Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558053 Share on other sites More sharing options...
JoeH Posted September 4 Share Posted September 4 You're missing your clearance lamp switch to the left of the dimmer. The switch to the right of the dimmer is park lamps down and park/headlights up. Middle is off. The Signal switch up top to left of steering wheel is forward flashes headlights, backward flashes taillights. Center dimmer switch controls the dash gauge brightness. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558054 Share on other sites More sharing options...
JoeH Posted September 4 Share Posted September 4 If you pick up that book I mentioned earlier it should largely have everything you need diagram-wise. Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558055 Share on other sites More sharing options...
JoeH Posted September 4 Share Posted September 4 It is possible someone wired everything onto the one switch on the right, but the switch isn't rated for that much electricity to go through it. Unless they wired it to control a relay instead. I know headlight switches melting is a common problem on older pickups, so they sell aftermarket relay kits where the headlight switch controls the relays instead. Quote Link to comment https://www.bigmacktrucks.com/topic/74492-r-model-electrical-help/page/2/#findComment-558056 Share on other sites More sharing options...
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