hey guys the heater in my 91 integra is acting up, it starting only workin on 3 and 4 speed which i researched and im thinking its the blower motor resister, but lately somestimes it doesnt work at all unless i play with the turn dial and push on it for a bit it usually starts working again just on 3 and 4 so wondering if theres another problem also before i order anything, thanks for any help!
go bone yard hunting, it’s proably the resister. Besides they’re cheap at a yard and easy to get to.
Agreed ^^ They are easy to replace once you remove the knee bolster panel. Its best to buy one from the junkyard since autozone sells cheap shitty ones for $65. 
**The resistor is right by this bro’s hand
perfect, thanks man!
ebay bnib are like 35 i believe
it is possible that it is the switch as well. i would check for 12v at the resistor pack, on all settings. you can use a 2$ test light. or make one yourself. if that checks out, replace the resistor pack
Your not going to find 12V at the resistor pack, or you better not, the resistor is on the ground circuit for the blower motor.
When the resistor is the problem it will normally work on fast speed, [direct ground from switch] and none of the other speeds.
However I do agree that that checking at the resistoris the easiest way to determine problem, to test, check for ground on 3 of the 4 leads at resistor plug, 1 of the 3 leads will, [should] test as a ground in each speed setting, the 4th lead goes to the blower motor.
You can also elliminate the blower motor as the problem by testing for power at the blower motor plug, [ign. must be on] if good supply aground directly to the other lead in plug, blower should run at full speed.
Because OP can get blower to work by, “play with the turn dial and push on it for a bit it” I would guess it is the switch. 94
[QUOTE=fcm;2238251]Your not going to find 12V at the resistor pack, or you better not, the resistor is on the ground circuit for the blower motor.
[/QUOTE]
ohhhh. because the resistor pack is after the load? is that what you mean?
No, the resistor is before the load… blower switch---- resistor---- blower motor ground terminal, blower speed is controlled by running the ground for blower through one or more resister(s). 94
but then if you were testing for voltage at the resistor pack connector, supplying your own ground through the dvom probe, probing each pin of the connector at its respective setting, you should see battery voltage for each one, no?
i mean, you would be bypassing the resistor(s) by doing this, so essentially voltage should remain at a constant.
not questioning your ability, of course. just trying to get an understanding
[QUOTE=welfare;2238595]but then if you were testing for voltage at the resistor pack connector, supplying your own ground through the dvom probe, probing each pin of the connector at its respective setting, you should see battery voltage for each one, no?
i mean, you would be bypassing the resistor(s) by doing this, so essentially voltage should remain at a constant.
not questioning your ability, of course. just trying to get an understanding[/QUOTE]OK I see what you mean, anytime you test a ground lead for any load, [blower motor in this case] that is not grounded and the power side is hot, [12V on power side of load] yes you will “see” power, but it is power through the load, it only tells you one thing, the load has continuity, [the circuit is complete] but that is all, and with a DVM, [that has no load] it will not tell you if the circuit is good under load, a 12V test light would be better because it does have a load, the light bulb. 94
ahhh yes. the fundamentals. no load, no draw.
thanks for taking the time. much appreciated
i changed the resistor and the heater is not working at all, also when i push the a.c button it doesnt light up blue anymore, so i think it might be the switch like fmc said.when i press a option for the heat like window or any of them it does make a noise when it changes over…could the switch just be loose, or would i have to order one… its pretty cold here, but when i get a chance i am going to take it apart and check behind the switch. any thoughts
if you have a multimeter, you can test for continuity of the switch in each setting.
as stated previously though, because you were able to get it to work by tampering with it, it probably is the switch/contacts
[QUOTE=murda613;2243843]i changed the resistor and the heater is not working at all, also when i push the a.c button it doesnt light up blue anymore, so i think it might be the switch like fmc said.when i press a option for the heat like window or any of them it does make a noise when it changes over…could the switch just be loose, or would i have to order one… its pretty cold here, but when i get a chance i am going to take it apart and check behind the switch. any thoughts[/QUOTE]Where did you get the resistor from?
First thing I would do is check for power at the blower motor plug, [2 pin plug], if you have power there, [ign. switch needs to be on] use a jumper lead to supply a ground directly to the blower motor, [second wire at blower motor plug] if blower motor works, [full speed] you know the problem is not power or the blower motor and you can leave the ground in place untill you fix the problem, so you have heat.
By your discription it sounds like the problem is at the switch, you will need to pull the HVAC control head so you can test the wiring at the plug at the back of the control head. I will get back to you on the wiring to check, it’s all grounds. 94
i got the resistor online its brand new and oem.where is the plug for the blower motor, i have a black wire and a blue wire going into the blower motor with a rubber around it,is that what your talking about, sorry if im missing it, im not too good with this stuff,id like to ground it and just have the high speed for now if thats easy to do,it would just come on automatically everytime i turn the car on right,thanks!
i got a test light, the blue and black wire, as well as the blue and white wire that go to the blower motor both test as power. any suggestions, do you think its still the switch…
Unplug the motor and test again.
A ground lead that is not grounded on a load, [blower motor in your case] will test as a power lead, you are seeing the 12V that is on the other side of the load. 94
alright, so unplug it and test and if it test as ground, then what do i do after that… thanks
Find which one is the power, and plug a ground jumper into the other one, plug it back into the blower motor. 94