Where Is the Location of the Headlight Relay on a 1982 Chevy S10 Pickup Truck

Username	Post: 1982 Chevy Truck Headlights Not Working. HELP. (Topic#309532)
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-20-14 02:28 PM - Post#2437317 My headlights, parking lights and instrument cluster do not work. My brake, hazards and blinkers do. I've wired tested the dimmer switch and headlight switch and there is no power so I'm assuming that it's not a switch problem. I can't seem to find a headlight fuse. Someone suggested that a fusible link on the firewall might be burned out, but I can't seem to find any that are burned. Plus, I don't really know which link I'm looking for. Can anyone help me fix this? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report

bry593 Contributor Posts: 831 Reg: 10-07-13 User Info Send Private Topic View Profile	03-21-14 05:39 AM - Post#2437441 In response to sutaabo There is no headlamp fuse. You pulled the light switch and then tested the harness plug? The large red wire should have 12V if the battery is connected. If not, there is a fusible link on the end of this red wire, near the battery. It will need replaced. A 16 gauge fusible link typically supports a 12 gauge circuit. If the fusible link is burned and not just cut or corroded, you need to find out why it fused. There is either excessive current load (headlamp mods?)or a short somewhere in the line (h/l switch?, dimmer?). Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-21-14 08:04 AM - Post#2437466 In response to bry593 I didn't pull the light switch when I tested it. I used a probe light tester and stuck in from the back side while the light switch was still connected. Should the red wire you mentioned, be constantly hot whether or not the ignition is on? Whether or not the light switch is on? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-21-14 08:07 AM - Post#2437468 In response to sutaabo It should. That's how your lights turn on with the vehicle off. or in my case forget to turn off the lights. 1990 r-1500 suburban, 350 TBI, 2wd Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-21-14 11:15 AM - Post#2437503 In response to ggenovez I tested every single wire at the light switch harness and none of them were hot, whether the ignition was on or not. 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-21-14 11:29 AM - Post#2437505 In response to sutaabo First thing I would do is set your meter to continuity and touch the probe to the red wire and the other probe to ground. If you have continuity, you have a short to ground. If that is fine then I would look for that fusible link that Bry mentioned, and see if there is voltage before and after the link. 1990 r-1500 suburban, 350 TBI, 2wd Email Report
bry593 Contributor Posts: 831 Reg: 10-07-13 User Info Send Private Topic View Profile	03-21-14 11:57 AM - Post#2437513 In response to ggenovez I was looking at the '82 truck diagram, it says the alternator is attached downline of the fusible link. That means if you start your truck, your lights should come on as powered directly off the alternator. It also means your alternator is no longer attached to your battery so the battery should be going dead. Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-21-14 12:09 PM - Post#2437516 In response to bry593 Bry is right. so it's either short and fused or broken, if that fusible link is broken. here are the diagrams 1990 r-1500 suburban, 350 TBI, 2wd Edited by ggenovez on 03-21-14 12:09 PM. Reason for edit: No reason given. Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-21-14 12:12 PM - Post#2437518 In response to bry593 OK, this is interesting!! My lights do NOT work no matter what I try. BUT, i did notice that my battery was dying. So I had the battery charged and tested. ALL GOOD. So then I started my truck and when I pull the battery cable, the truck dies. I thought there was a problem with my alternator, because, Unless I'm wrong, the truck should remain running even if you disconnect the battery. So when the truck died I thought there was a problem with the alternator. I removed it and had it tested and it passed on all tests! So what do YOU gentlemen make of that? And thank you so much for the help so far. It's given me hope to an problem I've yet to fix. 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-21-14 12:19 PM - Post#2437521 In response to sutaabo Look at the diagram. The alternator connects directly to the battery on that Red wire. If the fuse is blown you won't have any voltage. 1990 r-1500 suburban, 350 TBI, 2wd Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-21-14 01:42 PM - Post#2437542 In response to ggenovez OK. I'll check that tonight. Also, thank you for that diagram. It helps tremendously! 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
bry593 Contributor Posts: 831 Reg: 10-07-13 User Info Send Private Topic View Profile	03-21-14 06:41 PM - Post#2437617 In response to sutaabo Sounds like your alternator shorted internally. It will blow the fusible link and of course you will not have lights when you start the truck. Take it to the parts store and have them check the alt. Buy a link while you are there along with some heat shrink tubing to cover the splice. Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-21-14 08:55 PM - Post#2437647 In response to bry593 bry593, you missed where he said he pulled the alternator and had it tested and it passed. Again, I would start with the red wire, and test for continuity. if there is continuity unplug it at the switch and test for continuity again. Keep on doing so until you find where the sort is. What probably happened is the wire rubbed on something and wore off the insulation until it grounded and shorted. Shorts are a pain to find because you have to unplug every component and test until you find where the short is. Makes sense? So follow the diagram and unplug a component in line and test both sides until you find the short. Kind of like finding the burnt Christmas light in reverse. 1990 r-1500 suburban, 350 TBI, 2wd Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-24-14 07:26 AM - Post#2438350 In response to ggenovez Ok. So here's the scoop. I've inspected all wires leading in or out the alternator. They look like they're in bad shape. One of them has a bare spot. So I'm going to replace ALL wires going in or out of the alternator. I'll use the exact same size wire. (Unless you gentlemen know the ga sizes?) I know they should have a link or fuse on them. Do you happen to know what wires need fuses and what size fuse or fusible link??? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-24-14 08:57 AM - Post#2438369 In response to sutaabo Go with the same gauge. Too small and it will turn into a fuse and too large and you're paying more for something you don't need. Here is a picture of a fusible link. 1990 r-1500 suburban, 350 TBI, 2wd Email Report
bry593 Contributor Posts: 831 Reg: 10-07-13 User Info Send Private Topic View Profile	03-24-14 09:48 AM - Post#2438386 In response to ggenovez The red wire from the battery should be 10 gauge. The alternator can be the same if you like, but from GM, I think it is 12 gauge. USE SXL WIRE You can get it at Napa, or buy it online for a heap less money. SXL is special crosslinked thermoplastic for high temp, greasy areas and is what GM used. It is also the thickest jacket for excellent abrasion resistance. Do not use the general PVC stuff you find on the wall at AutoZone. The fusible link should have a rating for use with 10 gauge or 12 gauge. Essentially, it is a wire that is lighter by 4 gauges. For example, a 12 gauge main uses a 16 gauge fusible link. The fusible link in the pic above is the style GM used in 80's + vehicles. Earlier links are just a wire with a special jacket that doesn't melt off when it fuses. You simply solder (or crimp) inline at the battery (or starter) terminals. Napa should have both styles on hand. Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-24-14 10:45 AM - Post#2438401 In response to bry593 Ok. This is a ton of help. So please don't get annoyed with this question. 1. Is the SXL wire; the wire I use to replace my current wiring? All of it? (I'll refer to this in question 3. 2. Is a "Fusible Link" nothing more than a thinner wire that's connected right in the middle of the main wire? Like an inline fuel filter? EXAMPLE: 10" of 12ga SXL connected to 4" of 16ga sxl connected to another 10" of 12ga sxl? 3. Can I just buy 12ga and 16ga SXL wires and put a small section of 16ga wire in the middle of the 12ga wire on ALL three alternator strands? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
ggenovez Senior Member Posts: 998 Loc: DFW, Tx Reg: 06-08-05 User Info Send Private Topic View Profile	03-24-14 11:01 AM - Post#2438405 In response to sutaabo Sut, If we were to get annoyed, what's the point of helping people? 1.SXL is a type of Wire that is made to survive the conditions of an engine. Home depot wire won't do it. SXL 2. basically yes 3. No you don't want to do that. The burn rate of a 16 gauge is too close to your 12 gauge so it will melt the 12 gauge wire before the fusible link blows Here is a 14 gauge fusible link. I'm sure you can find a 12 gauge http://www.summitracing.com/parts/rnb-85620?seid= s... 1990 r-1500 suburban, 350 TBI, 2wd Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-24-14 11:10 AM - Post#2438409 In response to ggenovez Thanks! So I can buy a 16ga fusible link shown here: http://www.summitracing.com/parts/rnb-85621/overv i... and connect it to 12ga SXL wire on all three alternator wires and connect it to my Alternator? Do the pigtail wires coming off the alternator need fusible links? Or do I just need the ONE from the battery to the alternator? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
Vaughn Member #455 "15th Year" Gold Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Send Private Topic View Profile	03-24-14 01:27 PM - Post#2438443 In response to sutaabo The field wires (ones that plug into the top of the case - or in other words, any wires going to the alternator that are not the large output wire to the battery) are only to activate the electromagnet on the stator and for the alternator gauge/warning light. They really don't use much current, so you don't really need to go to the trouble of fusing them. Email Report
bry593 Contributor Posts: 831 Reg: 10-07-13 User Info Send Private Topic View Profile	03-24-14 01:28 PM - Post#2438444 In response to sutaabo Yes, that fusible link should work. You connect it in place of your current fusible link by cutting out the old and splicing in the new. On my '70 Chevy, the link is on a wire coming off the positive battery terminal to a junction block on the radiator core support. On my '80 Chevy, it is at the starter. Your '82 diagram shows it at the battery, but I'd check the starter too since that's where it is on my '80 model pickup. I recommend solering all connections and covering with double wall heatshrink tubing. That way you'll never have to fix again what you already repaired once. It takes more time to do it right the first time, but less time if you have to do it twice... Edited by bry593 on 03-24-14 01:31 PM. Reason for edit: No reason given. Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	03-31-14 08:21 AM - Post#2440673 In response to bry593 Ok Folks. Here's an update. I unwrapped all the wires leading from the battery to the starter, and the starter to the alternator, then the alternator to the firewall. What I found was terrible. Large gauge wires spliced into smaller gauge wires back up to larger ones. Several of the lines seem to have shorted. So, I think I"ve found the problem. I intend to replace ALL the wire with SXL wires of the appropriate gauge. I don't know if the wires on there now, are the correct size or not... So first question. How do I know what gauge a wire is? I'm starting with the alternator field wires, since I KNOW those are the correct size. But how do I tell what gauge those are? Is there some kind of diagram to help me? Can I get a tool to measure them? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
Vaughn Member #455 "15th Year" Gold Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Send Private Topic View Profile	03-31-14 11:01 AM - Post#2440710 In response to sutaabo Use 12 gauge wire on circuits that need a fair amount of current, or 10 gauge if it makes you feel better. These are the alternator wires that go to the battery or the starter, or that feed power to the inside of the truck. You also want to use it to feed the headlights and the power feed to the HEI. Use 14 gauge for any sensors or activation circuits (like the alternator field wires). Some stripping tools have guides for stripping different gauge wires, you can use that as a guide to tell you what gauge the wires are. Pretty quickly you will be able to tell what gauge a wire is just by looking at it. It isn't difficult to pick up. Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	04-01-14 10:24 PM - Post#2441173 In response to Vaughn So theoretically. If the alternator wiring is correct, and all fusible links are replaced then when the truck is running, I can pull the battery cables and the truck won't die. Correct? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Email Report
gchemist Member #271 Senior Chevytalk Moderator Posts: 25619 Loc: Austin, TX 78748 Reg: 05-09-00 User Info Send Private Topic View Profile	04-02-14 03:41 AM - Post#2441199 In response to sutaabo Weird but yea. '83 Silverardo XST - ZZ4 powered '95 Jimmy SLT (Bought @131,814) '96 GMC Jimmy LS Ret. @236651 miles '08 GMC Acadia 3.6L SLE Email Report
Vaughn Member #455 "15th Year" Gold Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Send Private Topic View Profile	04-02-14 10:19 AM - Post#2441310 In response to gchemist No, that only works on a generator equipped truck. On an alternator truck, it will immediately die. It is POSSIBLE that you might be able to do it on a self exciting alternator truck, but I wouldn't bet on it. Try it, you will see what I mean. My father had an old Studebaker truck with a generator that we could run without a battery. It would still die while driving without the battery. I had to drive the truck home several times without a battery because we had the musical chair version for batteries - 2 batteries and 3 vehicles. It would still die several times before I got home and would have to be jumped to get started again. The Studebaker is the only vehicle that would work on. Every time you tried that on an alternator vehicle it would die. Email Report
sutaabo Forum Newbie Posts: 23 Reg: 03-20-14 User Info Send Private Topic View Profile	04-02-14 12:44 PM - Post#2441345 In response to Vaughn Ok. Well Thanks Vaughn. So If I get the alternator wired up, how can I tell if it's actually charging the battery? I don't want to run down the road and it slowly die, wipers slowing, lights fading, until BOOM, it's dead. How can i tell that the alternator was wired correctly to charge the battery? 82 Chevy C30 Crew Cab 88 Chevy V10 Suburban Edited by sutaabo on 04-02-14 01:06 PM. Reason for edit: No reason given. Email Report
gchemist Member #271 Senior Chevytalk Moderator Posts: 25619 Loc: Austin, TX 78748 Reg: 05-09-00 User Info Send Private Topic View Profile	04-02-14 01:49 PM - Post#2441368 In response to sutaabo Voltage throughout wiring will be 13-14 volts. '83 Silverardo XST - ZZ4 powered '95 Jimmy SLT (Bought @131,814) '96 GMC Jimmy LS Ret. @236651 miles '08 GMC Acadia 3.6L SLE Email Report
Vaughn Member #455 "15th Year" Gold Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Send Private Topic View Profile	04-02-14 07:05 PM - Post#2441477 In response to gchemist IF it is charging well, it will be above 14 volts. If it is charging just OK, it will be in the 13 volt range. You may want to turn on all your accessories and then check the battery voltage. If it is down to the 12 volt range, your alternator is being overloaded. If you want, you can run it by a parts store and use their electrical system tester. Their tester will put a load on the alternator and determine if it is producing enough current. You don't have to take the alternator off, they have a tester that they just hook to the vehicle. Email Report
raycow DECEASED Posts: 27999 Loc: San Francisco, CA Reg: 11-26-02 User Info Send Private Topic View Profile	04-02-14 10:31 PM - Post#2441533 In response to sutaabo sutaabo Said: If the alternator wiring is correct, and all fusible links are replaced then when the truck is running, I can pull the battery cables and the truck won't die. Correct? Yes, if the alternator is charging you can disconnect the battery and the engine will continue to run. I have done this many times. Ray Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive. Email Report