alright people, im having a slight problem here.
and just for everyones info, i did search first.
this is the closest thread i found with my problem.
http://www.j-body.org/forums/read.php?f=11&i=76874&t=76874#76874
heres the thing. my rear defrotst on my green cavi isnt working. it is a 98 2.2L if anyone wants to know.
i checked continuity accross the grid, all ok there. the button pushes in fine, light comes on fine aswell. i have pulled the fuse, fuse is good. there is voltage accross the grid aswell. the driver side lead is the +voltage, the passanger the ground. everything checks out fine there.
when i was pulling the dash apart to remove the stereo i thought i would do a bit more inspecting. of the hvac and see if i could do any measuring since the relay is on the back of the hvac. i pulled off the harness for th a/c and defrost and i found the problem.
i will post pics when i get a chance to take them (camera was at the g/fs), but the best way to explain it is that a lead on the harness had physically melted! the lead must have overheated and actually melted rather than blow the fuse. i cant remember which letter this lead corresponded to, but when the lead is plugged into the hvac and the hvac is facing the rear of the car like it is when it is normally installed in the console, it is the top right wire lead (toward the passanger side of the car).
ya i was a little surprised about this. i mean the harness is shot, cant even be cleaned. i can splice and solder in a harness plug no problem. i hope the hvac control is ok.
does anyone know how to remove the hvac so i can test it in my 97 cavalier and make sure it still works? there is some residue on the hvac side lead that i should be able to clean. should i just get a new hvac from the scrap yard?
the only thing that i have done to the car electrically is install fog lihts that are now tapped off of a 12v switched line at the fuse pannel. now when i was installing the fogs to a switched source i had broken a connection or 2 that i tried to tap into but couldnt. one turned out not to be a switched source, the other was too big of a wire to solder everything together with me 100 w solder gun. all connections have been remade with crimps, though i am going to take my torch and resolder them with heat shrink. the fog lights are tapped into the battery side of the radio line (tapped in before it hits the fuse because the fogs have their own fuse).
i need some help with this one, what should i do? i dont want the dealer ship to say its the wiring i did, and i also dont want them to bend me over for the parts and labour.
Injection is nice but id rather be BLOWN!
the difference is, im getting voltage. in that problem, no voltage was had at the grid and/or the light wasnt turning on anymore for the rear defrost. i am getting voltage and the light is comming on. the problem is (from what i have gatherd) is i am not getting any current at the back grid. the currecnt is what heats the window, not the voltage. right now im getting voltage, but no current.
i went to the scrap yard today and ripped out the plug i needed with a few inches of wire too just incase i cant relocate the leads and need to solder and splice. i got 4 items for $10, so that worked out to $2.50 for the plug, so not a bad deal in my eyes. as far as i know the harness goes right back to the hvac, maybe further (wasnt going to get down on the floor of that car in the yard). i might see if i can go to the yard or even gm and get a whole new harness and replug it in so there isnt any splices.
i'll post pics up tonight hopefully.
Injection is nice but id rather be BLOWN!
here is some pics to help explain my problem.
im gonna have to make another trip to the scrap yard so i can fix this problem. i tried to unplug all the wires from the current and melted harness in the car and replace it with the one i had picked up the other day and only have to splice the one wire.
well i got frustrated and kids were comming to my door wanting candy (being its haloween and all) so i cut the @!#$in things up and taped off all the loose leads for another day. im just going to solder all the leads on the new plug and replace the thing to the hvac when the weather warms up and time permits.
im gonna go to GM and see if they will do anything for me, but i doubt it.
anyways, heres the pics.
that pic shows the melted plug.
another angle.
that is the burnt up lead that caused the whole problem.
and another angle of that too...
from what i remember of the orientation that wire and socket is the lower left side ( makred "D" on the plug). if anyone knows how far that harness goes to, like all the way to the blower motor, that would help in finding a replacement for it.
thanks everyone, any comments or suggestions would be helpful. also, if anyone else has had this problem and fixed it, or maybe has just lived with it for this long, maybe this can help lead to a solution.
maybe this is the answer to the "jump the two wires together when your rear defrost doesnt work" problem that has been floating around here for a awhile.
Injection is nice but id rather be BLOWN!
On my '93 that wire goes from the 30 amp power acc circuit breaker to S257 junction (off to the door locks) and then on to Pin D of Heater/A/c and Defogger assy.
Through Defogger On switch contacts and out of the control assembly via pin H (Ppl/wht) C305 ppl C307 (Ppl) on to the Positive connection of the Defogger grid.
The Ground connection is a Black wire to Point G317.
So you had a high resistance in the overheated section and no current in the grid!
I add this info just in case it is any help, Irealise it is an earlier model..
Good luck with fixing it
So you had a high resistance in the overheated section and no current in the grid!
Alont
that does help. at least it is a bit of an explanation as to what happend thanks for the info. im gonna go pay a visit to the scrap yard today on my lunch so i can get the new harness or the new socket atleast and either replace the whole thing or atleast solder in the plug so it will atleast be working for the cold weather.
thanks man.
Injection is nice but id rather be BLOWN!
Well common issue I see with defroster wiring harnesses melting like that, Is when you got youre heater on, lights on, defroster on it eats alot of current, In which causes this to happen from time to time, The rear defroster uses alot of current, Or sometimes people forget its on, Pop their goes the fuse panel fuse or wiring harness, Well you could get another wiring harness, Then rewire the old wires back to new harness,
Good Luck
ive picked up another new harness plug for the a/c and rear defrost so i can solder it back togther so it can work for the winter months atleast. when the weather warms up again i plan on replacing the whole harness. i believe that harness goes back to the blower motor, or atleast somewhere near it since its run with all the hvac controls and all that.
im going to find out what the new and old costs are on the harness, and maybe see if gm will hand me a new one or atleast i cheaper price.
it would be nice ( for me atleast) to see if anyone that has done the splice of the wires for their rear defrost to fix an issue has had the same problem. maybe the wire for our rear defrosts arent big enough to handle the current for that prolonged period of time, or maybe if anyone knows if there was a TSB posted up on this problem.
any help, much appreciated.
Injection is nice but id rather be BLOWN!
more @!#$ gone wrong!!!!
so i took the piece from the junkyard today and went to go solder it in. turns out it is a different plug. i took this one out of a sunfire, unsure of the year, and the wires are in a different position. i thought to myself i would just look at the 97 i bought and that would help me figure out the problem on the 98. wrong again!
turns out my 97 is like the sunfire piece i took out of the scrap yard, but again it is a different plug. atleast its not as different as the 98. the 98 and the piece i have, the wires are in completely different spots.
while i was proding around back there, i thought i would pop out the printed circuit board with the built in relays for the defrost and a/c. turns out that even if it had the proper wiring to just solder in the plug, the bottom of the circuit board was screwed up because some solder melted too.
so im taking that cicuit board with me tomorrow when i go to the yard. im going to grab the whole circuit board out of it and make sure it is the same as the one that the 98 came with.
im frustrated now. i just want the defrost to work so my mom and dad dont snap on me.
oh, and i also scored a OEM CD player for them for $50. the rest of the stuff i had he didnt charge me for, just the cd player.... at least the day wasnt a total waste.
Injection is nice but id rather be BLOWN!
where did ya get that plug from!?!? i think i have to replace that then cause mine doesn't work either jus light and nohtin but when i replace the fuse it sparks on contact and blows it right away!! is that whats causing!?
98'zeta veinte-quatro
(z24)......
mine never blue the fuse...
anyways when i was at the junk yard today i found the entire harness, it was out of a 00+ though so i just cut out the plug and took the circuit board.
the ENTIRE harness from gm (im hoping they quoted me the wrong one cause the guy wasnt 100
is $1400 CDN!
it seems that the harness in the scrap car went from the HVAC through the dash to around the air bag where it split off into 2 directions. one went left through the dash, where im assuming it goes to the fuse panel or something. the other direction it went was under the passanger side airbag and to the blower motor. where it went left it actually had a male and female plug type connection. i dont know if my car is the same or if all the cars are like that with that connection, but if they are then that side of the harness could stay and the one that goes from the HVAC to the blower be replaced.
for now, im going to be splicing the new plug in. i need to go get a tear down guide though, cause im an idiot and cant remember which of my wires that are cut in the dash go to where. plus, i have 2 brown wires on the original harness and the new one has a brown and brown with white stripe.
this should be a fun night....
Injection is nice but id rather be BLOWN!
so the problem was fixed last night.
i solderd and used heat shrink to splce in a new harness and pluged that into the new circuit board. all seems to work ok right now. i havent been able to test and see if the defog is actually defogging or not because the window was clear last night and this morning.
the two thicker gauge wires ( i believe they are 10 AWG) were too thkc for me to solder with both my 100W gun and my butane torch ( i was starting to melt the insulation, need more practice with my torch). for the time being they are just crimped and taped.
anyways, im going to take pictures of this fix when i get a chance, until then i'll just let all of you know if you run into a problem like this it can be fixed.
Injection is nice but id rather be BLOWN!
i think i am having the same problem but i cant get the plug off the back the check i removed the 2 blue clips but it still wont come out
Any thoughts
