baddog8it Posted December 4, 2018 Author Share Posted December 4, 2018 Disconnect your brake light switch to see if your brake lights are still on. when brake switch disconnected, there are no brake lights (but running lights work normally) Link to comment Share on other sites More sharing options...
vjsimone Posted December 4, 2018 Share Posted December 4, 2018 when brake switch disconnected, there are no brake lights (but running lights work normally) I quess you are going to have to check the wiring you did. Seems you are also not getting a good connection in there for the brake light pass thru,I suggest you clean off the grease you applied. With the flasher removed & the brake switch disconnected you should not blow a fuse, unless there is a short in a wire somewhere in the path to the flasher of brake switch. Link to comment Share on other sites More sharing options...
vjsimone Posted December 4, 2018 Share Posted December 4, 2018 FYI - dielectric grease is an insulator and inhibits current flow. Link to comment Share on other sites More sharing options...
grumpin Posted December 4, 2018 Share Posted December 4, 2018 FYI - dielectric grease is an insulator and inhibits current flow. Vinny mentioned to check the trailer wiring. I second that. When I got my truck I needed to replace the turn signal switch, one of the tabs that hold the turn signal on was broke. Afterwards, IIRC, I was also blowing the fuse for the brake lights and my tail lights were intermittent and the license plate lights were not working. The trailer wiring had been spliced into and wired incorrectly. Ended up getting it all out where I could see it and got the EVTM out and straightened it up, been fine since. Hope you get this soon, these kind of problems can drive you nuts. Link to comment Share on other sites More sharing options...
baddog8it Posted December 5, 2018 Author Share Posted December 5, 2018 Vinny mentioned to check the trailer wiring. I second that. When I got my truck I needed to replace the turn signal switch, one of the tabs that hold the turn signal on was broke. Afterwards, IIRC, I was also blowing the fuse for the brake lights and my tail lights were intermittent and the license plate lights were not working. The trailer wiring had been spliced into and wired incorrectly. Ended up getting it all out where I could see it and got the EVTM out and straightened it up, been fine since. Hope you get this soon, these kind of problems can drive you nuts. So last night I dug back into it. First I double checked my wiring at the C305 connector - all was fine. Then pulled the steering wheel. Low and behold, this is what I found... I cleaned up everything, used some liquid tape to insulate the exposed copper, and tucked it away out of harms way. I was confident that that a bare wire rubbing on the steering wheel had to be the problem and set about putting everything back in place - fully wrapping it up. Reinstalled brake switch connector, hazard flasher and verified I had a good fuse in place. UGH!! Symptoms still exist (at least some of them). I unplugged the brake switch connector so that I'm not running down the battery. Everything still seems to act the same with the possible exception of the fuse shorting. I think that either the flasher/turn signal assembly is wired wrong or has an internal short, or there is a problem in an aft wiring harness as others have alluded to. I'll have to wait for the driveway to dry off enough so that I can go crawling around under the rear end of the beast! thanks for the support and helpful info! Hopefully I can get this resolved quickly. Link to comment Share on other sites More sharing options...
baddog8it Posted December 5, 2018 Author Share Posted December 5, 2018 So last night I dug back into it. First I double checked my wiring at the C305 connector - all was fine. Then pulled the steering wheel. Low and behold, this is what I found... I cleaned up everything, used some liquid tape to insulate the exposed copper, and tucked it away out of harms way. I was confident that that a bare wire rubbing on the steering wheel had to be the problem and set about putting everything back in place - fully wrapping it up. Reinstalled brake switch connector, hazard flasher and verified I had a good fuse in place. UGH!! Symptoms still exist (at least some of them). I unplugged the brake switch connector so that I'm not running down the battery. Everything still seems to act the same with the possible exception of the fuse shorting. I think that either the flasher/turn signal assembly is wired wrong or has an internal short, or there is a problem in an aft wiring harness as others have alluded to. I'll have to wait for the driveway to dry off enough so that I can go crawling around under the rear end of the beast! thanks for the support and helpful info! Hopefully I can get this resolved quickly. Quick question - I don't have a build sheet available, so what's the simplest way to determine if my beast has the factory trailer wiring? Edit - a bit of clarification. Looking at the '85 EVTM on page 134, it appears that the 'TRAILER OPTION' includes a 'TRAILER ELECTRIC BRAKE CONTROL' which is attached to the brake pedal. Compare that to the diagram on page 79 (showing turn/brake lights), there are greyed out areas labelled 'TRAILER ONLY'. Are these areas and items labelled 'TRAILER ONLY' the same as the 'TRAILER OPTION'? i.e.. If I don't have the trailer option, I can and should ignore anything labelled 'TRAILER ONLY'? Link to comment Share on other sites More sharing options...
grumpin Posted December 6, 2018 Share Posted December 6, 2018 Quick question - I don't have a build sheet available, so what's the simplest way to determine if my beast has the factory trailer wiring? Edit - a bit of clarification. Looking at the '85 EVTM on page 134, it appears that the 'TRAILER OPTION' includes a 'TRAILER ELECTRIC BRAKE CONTROL' which is attached to the brake pedal. Compare that to the diagram on page 79 (showing turn/brake lights), there are greyed out areas labelled 'TRAILER ONLY'. Are these areas and items labelled 'TRAILER ONLY' the same as the 'TRAILER OPTION'? i.e.. If I don't have the trailer option, I can and should ignore anything labelled 'TRAILER ONLY'? Dang it! I don't remember well anymore. I had that same thing happen, it was blowing my fuse, then I found the trailer wiring all messed up because of my tail and license lights. On the trailer option, I believe you will have a trailer lamp relay by the fuel pump relay on the left firewall to the left of the brake master cylinder. Also you will find wires that are white with a red dash for your year I believe, at the trailer plug. Also a bigger yellow wire for 12v trailer power. HTH! Link to comment Share on other sites More sharing options...
vjsimone Posted December 6, 2018 Share Posted December 6, 2018 So last night I dug back into it. First I double checked my wiring at the C305 connector - all was fine. Then pulled the steering wheel. Low and behold, this is what I found... I cleaned up everything, used some liquid tape to insulate the exposed copper, and tucked it away out of harms way. I was confident that that a bare wire rubbing on the steering wheel had to be the problem and set about putting everything back in place - fully wrapping it up. Reinstalled brake switch connector, hazard flasher and verified I had a good fuse in place. UGH!! Symptoms still exist (at least some of them). I unplugged the brake switch connector so that I'm not running down the battery. Everything still seems to act the same with the possible exception of the fuse shorting. I think that either the flasher/turn signal assembly is wired wrong or has an internal short, or there is a problem in an aft wiring harness as others have alluded to. I'll have to wait for the driveway to dry off enough so that I can go crawling around under the rear end of the beast! thanks for the support and helpful info! Hopefully I can get this resolved quickly. Yeah, that White/Red wire with the bare spot is the 12v power to the switch from Fuse #1 via the Hazard Flasher, if that shorts, bam, fuse #1 gone, so you have found one problem. Link to comment Share on other sites More sharing options...
vjsimone Posted December 6, 2018 Share Posted December 6, 2018 Quick question - I don't have a build sheet available, so what's the simplest way to determine if my beast has the factory trailer wiring? Edit - a bit of clarification. Looking at the '85 EVTM on page 134, it appears that the 'TRAILER OPTION' includes a 'TRAILER ELECTRIC BRAKE CONTROL' which is attached to the brake pedal. Compare that to the diagram on page 79 (showing turn/brake lights), there are greyed out areas labelled 'TRAILER ONLY'. Are these areas and items labelled 'TRAILER ONLY' the same as the 'TRAILER OPTION'? i.e.. If I don't have the trailer option, I can and should ignore anything labelled 'TRAILER ONLY'? Also look on your brake pedal to see if you have a Brake Controler. Link to comment Share on other sites More sharing options...
vjsimone Posted December 6, 2018 Share Posted December 6, 2018 So last night I dug back into it. First I double checked my wiring at the C305 connector - all was fine. Then pulled the steering wheel. Low and behold, this is what I found... I cleaned up everything, used some liquid tape to insulate the exposed copper, and tucked it away out of harms way. I was confident that that a bare wire rubbing on the steering wheel had to be the problem and set about putting everything back in place - fully wrapping it up. Reinstalled brake switch connector, hazard flasher and verified I had a good fuse in place. UGH!! Symptoms still exist (at least some of them). I unplugged the brake switch connector so that I'm not running down the battery. Everything still seems to act the same with the possible exception of the fuse shorting. I think that either the flasher/turn signal assembly is wired wrong or has an internal short, or there is a problem in an aft wiring harness as others have alluded to. I'll have to wait for the driveway to dry off enough so that I can go crawling around under the rear end of the beast! thanks for the support and helpful info! Hopefully I can get this resolved quickly. So, you are replacing the Brake Light switch right? In the mean time, jump the 2 wires for the Brake Light switch to see if the lights get brighter. Also check connector 305 for bent pins/blades. Link to comment Share on other sites More sharing options...
Recommended Posts