AC Ballast Resistor
05-27-2009, 01:30 AM
#1
AC Ballast Resistor
We replaced the AC Ballast Resistor last winter as a preventative maintenance issue -- essentially used it one season -- tonight the fan cycles on and off -- from reading the posts on RL it seems to indicate that this is a sign of a bad ballast resistor - having a hard time believing that a newly replaced resistor would be bad - any other thoughts?
05-27-2009, 11:02 AM
#3
Track Day
Join Date: Apr 2009
Location: The Netherlands
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Do you mean the resistor below your rear blower?
The one with the spiral?
If this is the one you mean then I would recommend to change your heat sensor above this resistor.
On the resistor is a bi-metal that opens when he gets hot and shut dowm the current of the resistor.
After cooling down the bi-metal makes contact and the spiral gets again hot and so on.
I had the same problem and after changing the sensor everything was OK
The one with the spiral?
If this is the one you mean then I would recommend to change your heat sensor above this resistor.
On the resistor is a bi-metal that opens when he gets hot and shut dowm the current of the resistor.
After cooling down the bi-metal makes contact and the spiral gets again hot and so on.
I had the same problem and after changing the sensor everything was OK
05-28-2009, 01:21 AM
#4
No - it's not the resister in the engine compartment - it's the ballast resistor which is located on top of the A/C condensor fan in the left front wheel well.
Do you mean the resistor below your rear blower?
The one with the spiral?
If this is the one you mean then I would recommend to change your heat sensor above this resistor.
On the resistor is a bi-metal that opens when he gets hot and shut dowm the current of the resistor.
After cooling down the bi-metal makes contact and the spiral gets again hot and so on.
I had the same problem and after changing the sensor everything was OK
The one with the spiral?
If this is the one you mean then I would recommend to change your heat sensor above this resistor.
On the resistor is a bi-metal that opens when he gets hot and shut dowm the current of the resistor.
After cooling down the bi-metal makes contact and the spiral gets again hot and so on.
I had the same problem and after changing the sensor everything was OK
04-21-2010, 11:08 AM
#6
I doubt you're as stupid as me - but just in case....
Years ago, I replaced my ballast resistor and found the fan still cycled on and off. After checking, I realised that although it looked like I'd plugged the resistor into the loom, I hadn't lined the connector up correctly so it wasn't actually making contact - even though it does look like it's connected.
I very much doubt this is your problem - but just in case....
Years ago, I replaced my ballast resistor and found the fan still cycled on and off. After checking, I realised that although it looked like I'd plugged the resistor into the loom, I hadn't lined the connector up correctly so it wasn't actually making contact - even though it does look like it's connected.
I very much doubt this is your problem - but just in case....
04-21-2010, 12:06 PM
#7
Rennlist Member
mine does this too and still looking for a solution. I replaced my resistor also and it still does it. I jumped the pins at the relay and it works fine, so im guessing its a problem with the control head at this point.
Trending Topics
04-21-2010, 08:29 PM
#8
04-21-2010, 10:21 PM
#9
Advanced
I had a similar problem on the other side with my oil cooling fan - thought it was the resistor (fan was stuck on), but as it turned out all I had to do was pull the relay out with the car off (battery was disconnected), then put the relay back in and that solved the problem. Don't know if it will help on the A/C fan, but it's free and worth a shot.
04-21-2010, 11:09 PM
#10
Racer
Join Date: Feb 2004
Location: Silverthorne, Colorado
Posts: 373
Likes: 0
Received 15 Likes
on
3 Posts
Two problems. They maybe related or not.
1. No deforest air comes out of passenger side. Drivers side is fine. - I check the servo's and all of them that I could see, seem to be operating.
2. The condenser fan cycles on and off every 3 seconds- I check the following:
-Low side pressure is at about 40 (134a) so seems ok
-I switched out the R14 relay - No change in operation
-I checked the # 39 fuse- It was blown. I replaced it and it immediately blew again. I replaced it again,
It has been over a week and this fuse has not blown again> Weird.
- I jumped 30 and 87C (slow speed) did not come on with the car off. I could not hear if the condenser fan came on when the car was running. The car is a bit loud with my exhaust mods,oh well.
- I jumped 30 and 87 (high speed) and the condenser fan came on immediately, without the car running. When the car was running the fan continued to run. In both conditions the fan ran constantly without cycling.
- Inside the car the force of the air coming out of the vents is moderate. At times it blows harder but that will only last a few seconds and then it will blow at moderate force again for 30 seconds or more before it tries to blow hard again.
Everything i have read points towards the Ballest Resistor, the 3 level pressure switch or possibly the head unit.
Any thoughts?
Thank you in advance,
Peter
1. No deforest air comes out of passenger side. Drivers side is fine. - I check the servo's and all of them that I could see, seem to be operating.
2. The condenser fan cycles on and off every 3 seconds- I check the following:
-Low side pressure is at about 40 (134a) so seems ok
-I switched out the R14 relay - No change in operation
-I checked the # 39 fuse- It was blown. I replaced it and it immediately blew again. I replaced it again,
It has been over a week and this fuse has not blown again> Weird.
- I jumped 30 and 87C (slow speed) did not come on with the car off. I could not hear if the condenser fan came on when the car was running. The car is a bit loud with my exhaust mods,oh well.
- I jumped 30 and 87 (high speed) and the condenser fan came on immediately, without the car running. When the car was running the fan continued to run. In both conditions the fan ran constantly without cycling.
- Inside the car the force of the air coming out of the vents is moderate. At times it blows harder but that will only last a few seconds and then it will blow at moderate force again for 30 seconds or more before it tries to blow hard again.
Everything i have read points towards the Ballest Resistor, the 3 level pressure switch or possibly the head unit.
Any thoughts?
Thank you in advance,
Peter
04-22-2010, 01:04 AM
#11
Rennlist Member
if you jumped the low speed connectors and the fan did not come on, then the resistor is bad, or disconnected. basically what you're doing at the relay by jumping the pins, is sending voltage directly to the resistor, which in turn creates a voltage drop which is then sent to the fan so the fan only receives 6 or so volts, so it will turn slower. So if you did that and the fan does not work, then somewhere between the relay and the fan is an open circuit, or more likely, a blown resistor.
