[QUOTE]Originally posted by Mickey_Moose: Using crimp connectors is not usually a good way - you should solder the pieces together. Only way to make sure you have a good connection in the coming years.
I have seen way too many crimp connectors go bad in my 20+ years in the electrical/electronics field - but that is just me.
Solder have problem too. Many use way too much and wicked solder can change spec's for the link. Many people don't get the joint hot enough and make "cold" joints. Cold joints may look fine to most people but will bite you down the road. (Cold joints at the factory are part of why "blue dingy thingy" dies.)
Most pre-attach crimp are not water proof and water, road salt, etc, will rot the main and link wires. Worse, Users don't even try to water proof them by using silicon oil/grease. (Silicon won't attack plastic insulation.) I've see Inches to Yards of wire rot because 1 repair isn't water proof and water wick down the wire.
You often can remove insulated non water proof crimps w/o cutting wire. Look at crimp area. Put pliers etc 90° to crimp zone and expand the crimp by crushing only a bit. Clean wire's insulation to remove grease etc. Then use "weather proof" crimps and heat it after to shrink the tube and melt the glue.
Note that Iffy/Bad link to wire joints or terminals can make the link hot. Wire will be a heatsink for bad joints.[/QUOTE]
Yes I agree, you have to do a decent job at soldering (the solder has to wick, but not far enough to make the link pointless as you said - just need to wick the splice). I have never had a solder joint fail on me in all my years (I have been in the electronics field since 1986, mostly service and have done it all consumer to industrial, but now working research and development) - crimps, yes, no matter how good they are the wires inside the crimp can still break and if you get oxidation forming, then it is only a matter of time.
The cold solder problem with the "blue diny thiny" is common with all electronics with single side circuit boards (can happen on double sided boards as well, but is far less common). Any electronics of this age will have cold solder joints which develop due to heat and cooling cycles as well as movement/vibration. A lot of modern electronics have the larger (or any that can possibly move) parts "glued" to the circuit boards/other parts for this reason. Also most quality boards now days are multi-layer with any through holes plated all the way through - still single layer boards will have this problem, especially at any connectors.
The best water proofing is to buy and use weather proof heat shrink and a proper solder job.
In my industry fusable links are melt out style do to burner heat (24vac circuit is broke to the gas valve) The hot spot is the source of the problem electrically in AC voltage. I assume the rules are the same so I suspect the fusable link. Like a fuse in the car a voltage in millivolts cans be checked across a fuse to determine a battery drain. Maybe the volts checked across the fusable link will show a drop because of resistance in the link. If the link is that hot the wire should be pretty hot also if there was something in the circuit other than the link. Most of the circuits in the link A look like control circuits, if not all I didn't look that close.
Originally posted by LornesGT: In my industry fusable links are melt out style do to burner heat (24vac circuit is broke to the gas valve) The hot spot is the source of the problem electrically in AC voltage. I assume the rules are the same so I suspect the fusable link. Like a fuse in the car a voltage in millivolts cans be checked across a fuse to determine a battery drain. Maybe the volts checked across the fusable link will show a drop because of resistance in the link. If the link is that hot the wire should be pretty hot also if there was something in the circuit other than the link. Most of the circuits in the link A look like control circuits, if not all I didn't look that close.
Again... Fusible Link Wire is normal copper. The insulation is "fire proof" to prevent fried link ends shorting to frame etc.
If you measure Voltage Drop on a link then link is toast or your equipment has problems. Is not like VD testing for battery cables w/ active starter. Iffy battery cables and high draw motor can easily drop 1-5v.
Better tool is AC/DC amp clamp meter. This tool can answer most questions w/o taking thing apart, often in a few minutes. Note Many used meters are AC only. Carefully look at the unit before buying.
Yes mine gets driven almost daily. But I quit using the air conditioning last year and planned in buying the amp clamp to do more diag this year...using ac overloads causes the wire to get hot.
Originally posted by 88cryan: Yes mine gets driven almost daily. But I quit using the air conditioning last year and planned in buying the amp clamp to do more diag this year...using ac overloads causes the wire to get hot.
AC Clutch Coil pulls 5-8 amps normal, more if have shorted coil winding etc.
Often Need current and volts even using amp clamp. Volts when whatever is on. Easy by back probing connectors. Carefully use a needle or two to probe seal side of connector. Google it for more. YOU CAN EASILY SHORT THE CONNECTOR w/ this using 2 needles.
If motor ground thru same then need two needles... While Back probing for motor volts, check ground for volt drop to frame (motor on) and Ω to frame (motor off) Both should be close to 0. G101 and G102 (and others in engine bay) are known to rot from road salt etc. I always clean and silicon them. If screws are loose from rust/stripping, drill new holes.
Today I was poking around and I was feeling all the wiring and relays I could easily touch.
fuse link A is still very hot the battery to alternator cable is very hot the fuel pump, a/c control, and blower motor relays are all hot to touch
I back probed the fuel pump connector on the passanger side (tan/wht) and while running I touched the battery + and got a reading of 1.87. So I'm loosing almost 2 volts on the positive of the fuel pump (max allowable voltage drop >.50 volt) The negative side tested at .09 so ground is good.
EDIT: A/C control relay is loosing 1.23 volts at the relay (easiest place to access, would prefer compressor clutch directly but its night right now and I'm doing this in my apartment parking lot.
ALSO: I have the both the compressor and fuel pump relays un-plugged right now and fuel pump hooked to battery power. The fusible link and alt cable are still burning hot even with those bad loads out of the system.... stumped
Cooling fan had a voltage drop of .60 and blower motor .83
The headlights use link B but I tested them too since I was there and they are loosing 1.30 volts
[This message has been edited by 88cryan (edited 06-26-2016).]
Been a long time since I checked in on this thread, but I you sure your battery cables are in good shape? What is battery voltage at the alternator with the engine OFF?
Battery voltage at the alternator while off, no problem there. I have been doing some heavy diagnostics and I determined everything powered by Fuse link A is 1 volt short compared to battery while running and under load. So when I voltage drop test the blower motor, radiator fan, a/c clutch coil, fuel pump, etc they show 1.23, 1.14, 1.06 etc. So they have an acceptable voltage drop because really it it .23,.14,.06 which is under .50 volt drop. I traced the 1 volt drop all the way to the fuse block and ignition switch so far. I tested the two red input wires to the ignition switch and also found the 1 volt drop so the ignition switch is actually good. I tested the voltage drop at the fusbile link and it was .15........So the voltage drop of 1 volt is being dropped somewhere between Fusible link A and the input of the ignition switch. That could be S206 or the bulkhead connector or the wire in between. Hopefully I will figure that out this weekend!!!!!
I took the dash out and in case you all are wondering S206 is buried and hidden out of site in the main harness behind the steel reinforcement beam. I couldn't actually get to it without taking the column out and disconnecting everything to pull the harness through.....but I did probe the red wire right before it disappears and at the fuse box and no alarming increase in voltage drop. The wire itself looses quite a bit of voltage just in length. I think it should have been larger from the factory.
For example here are my recorded drops along the Red primary wire; Battery terminal 0.00 after Fuse link A 0.15 after bulkhead connector 0.35 near shifter assembly 0.59 before dissappears and S206 0.82 At fuse box and and accessories 1.00 volt drop
Also according to my 88 factory service manual 1 volt is an acceptable voltage drop (I thought .50 was but I only work on 10 year old cars and newer at my work) Someone reading this if you have time touch your Fusible Link A wire while everything has been on for 5 mins and tell me if its hot. Starting to think its normal as I just proved my drops are acceptable and my amp draws were reasonable. If this is normal I'm considering running a 2nd 5mm power wire that also has the same size fusible link and merge it into the harness before S206....Or go through the trouble and split up S206 somehow.
Instead of running new wire, I would consider just replacing the fusible link with a maxi fuse. Fusible links work by being "undersized" for the current they transmit. if Circuit A runs 20a and requires 16ga wire to be reliable, the fusible link for Circuit A is 18ga wire and will fail before the rest of Circuit A's 16ga wire does, limiting potential damage to that fusible link. I completely made those numbers up because I can't be arsed to look them up, but that is conceptually how that works. As a result of being undersized, fusible links will run hotter than adjacent wire. How hot "too hot" is will be a matter of science I don't know, but have confidence that if it's not failed, it's probably within the design envelope. A maxi fuse provides the same protection and same "slow blow" attributes as a fusible link, so if you're concerned about the properties of your link, just replace it with a maxi. It's the right approach.
If you really want to run new wire, you can duplicate what you've got. Same size wire with the same fusible link. Remember that will double the capacity and halve the current each side has to carry, so you have to down-size the fusible link on each leg to get the same protection level.
Ok, so I'm reading this thread with interest as I have an 86 SE which had an interior fire which I am putting a used harness in. The Fusible links in the used harness look a little questionable with some degradation of the insulation. I was thinking about replacing them until I read your story. Now I'm thinking I'll install the harness as is and monitor the fusible links. When I get my car running I will do some of the same tests you have done and report back.
Question for you: When you replaced the fusible links did you match the length of the originals? A longer length would have additional resistance.
As Ogre mentions above, fusible link isn't resistor wire. It's just normal copper wire with special insulation. The "added resistance" of additional length is negligible, probably not even measurable with conventional equipment. If the insulation on the fusible link of the replacement hardness is damaged you NEED to replace that link. When a fusible link fails, the copper wire MELTS and the insulation is what prevents multi-hundred degree wire from starting a fire. If that molten metal makes it out into the world it could contact something less fire-resistant and then you have another car fire. The "fail by catastrophe" is why fusible link is not used much anymore in cars. You can still find it if you look hard enough, but with solutions like maxifuse, AMI/AML, and megafuse there isn't much reason to risk a fusible link fire.
Any solution to this problem yet? I'm following along with interest.
I know Orge said the link should never be hot and I've never actually touched mine to know, but I recall 25 years ago, I was traveling cross country, middle of no where, and the non-Fusible Link on my 84 went out. Miles from a phone or a tow truck, I 'hot wired' power across the fuse panel under the dash to get me going to a service station, and I can tell you my jumper wire across the fuse block was hot enough to melt the insulation off the wire.
After the link was replaced it was good for 80k miles or so until it went out again. After that 2nd failure I relocated the link away from the hot exhaust.
I bought a single fusible link kit from autozone so the length was already calibrated and I didn't alter them. If you bought bulk fusible link wire it would probably be cut to same length.
quote
Originally posted by Jefrysuko:
Question for you: When you replaced the fusible links did you match the length of the originals? A longer length would have additional resistance.
Any solution to this problem yet? I'm following along with interest.
I know Orge said the link should never be hot and I've never actually touched mine to know, but I recall 25 years ago, I was traveling cross country, middle of no where, and the non-Fusible Link on my 84 went out. Miles from a phone or a tow truck, I 'hot wired' power across the fuse panel under the dash to get me going to a service station, and I can tell you my jumper wire across the fuse block was hot enough to melt the insulation off the wire.
After the link was replaced it was good for 80k miles or so until it went out again. After that 2nd failure I relocated the link away from the hot exhaust.
I know 84's had a different fusible link setup. If I remember their links were located near the starter down low and got hit with the elements. Mine (and 1985?-1988) have them located at a junction block under c500 by the battery. It could be that your jumper wire was to small for the loads (Fuse A powers just about everything except headlights).
I have not found a solution yet but I am working on it and will keep everyone updated. Bypassing fusible link A and the wire is my next diag step.
So today I was replacing the ignition tumbler on my friends 87gt automatic and I started it up after my repair and kicked on max a.c.. After a few mins I grabbed it's fusible link A and it was burning hot too! This car had everything stock down to the radio and factory fusible wiring, I'm leaning toward design flaw instead of issue. I wish I could find more cars/people to check.
Just an update, I am calling the hot fusible link a design flaw in our electrical system. I checked every load on the circuit, checked the wiring itself, and couldn't find anything "abnormal" with the system besides the hot link. Also I have checked and found this problem on 5 different Fiero's, including my new 88 coupe 2.5.
Short story.. The link on my 86 GT gets pretty hot to the touch as well. It does not burn but gets hot. I would say run the thing. Links are designed to take the heat and are the weak point in the system for a reason.
[This message has been edited by Easy8 (edited 05-10-2017).]
