Do I have a bad relay if my ac comes on only when i hit a bump 2010 audi a4

Asked by Jul 27, 2017 at 03:54 PM about the 2010 Audi A4

Question type: Maintenance & Repair

9 Answers

5,800

Could be anything electrical or a weak clutch magnet on your compressor. Loose connection, split wire making contact, something loose in or under fuse box. Relays do get weak and work intermittently and sometimes with a hit on them or close by. Ground wire loose? Connections to compressor all tight?

I will check all my connections Thank you

5,800

See if you have an identical relay that matches the AC relay in the box and interchange them to see if the other circuit now has issues. Many times the horn relay is the same as the AC clutch relay. MCLT is what many makers label the compressor relay.

The compressor will come on and the blower is not so then I open the hood and drop it. and the blower will work? Car has 42000 miles

5,800

Check the blower resistor on your car. Generally on passenger side in cabin by the persons feet or up a little under dash. Close to the blower that blows across evaporator. Google it for your car and location. About $30 - $40 of this is it. Also find the fuse or relay that runs this blower circuit and see if it is a bad relay, fuse or loose connection in circuit? Do a continuity test from inside cabin to fuse box location of that circuit. Also does some (not all) speeds work on this resistor? This is GENERALLY 100% proof that this resistor is bad. If this is good could be the control board on dash or wiring to this control board.

5,800

Blower motor resistor. Sorry. It is an easy replacement on most cars. If this is your issue...

Thanks I will check all connections, all speeds work fine when I take it off auto. And the Blower resistor for the Audi is $400.00 and the blower motor is $125.00 This is what has led me to believe that maybe I have a bad relay?

5,800

Bad Audi for those prices!!! On a serious note, Relays are very easy to check and are cheap online. I have even gone to a junkyard and pulled the entire box for pennies on the dollar. YouTube how to check a relay. It is easy! Pull a few (mark where they went) see if the one in question has a weaker clicking sound or has higher ohms than similiar ones. See about pin fittment is good in the box or if there are any melting or burn marks where this relay fit.

Thank you!!

Your Answer:

A4

Looking for a Used A4 in your area?

CarGurus has 6,114 nationwide A4 listings starting at $1,300.

ZIP:

Audi A4 Experts

  • #1
    Deathjam4
    Reputation
    4,860
  • #2
    lukeyramone
    Reputation
    740
  • #3
    F_O_R
    Reputation
    510
View All

Related Models For Sale

Used BMW 3 Series
991 Great Deals out of 28,591 listings starting at $1,550
Used Audi A6
133 Great Deals out of 7,056 listings starting at $1,995
Used Audi A5
79 Great Deals out of 2,133 listings starting at $5,995
Used Audi S4
35 Great Deals out of 799 listings starting at $4,777
Used Audi A3
170 Great Deals out of 3,403 listings starting at $2,900
Used Mercedes-Benz C-Class
1,036 Great Deals out of 28,160 listings starting at $1,100
Used BMW 5 Series
483 Great Deals out of 19,754 listings starting at $1,700
Used Honda Accord
1,063 Great Deals out of 86,345 listings starting at $1,200
Used Audi Q5
251 Great Deals out of 13,433 listings starting at $7,500
Used Ford Mustang
675 Great Deals out of 39,790 listings starting at $1,795
Used Dodge Charger
613 Great Deals out of 29,775 listings starting at $1,500
Used Mercedes-Benz E-Class
644 Great Deals out of 22,039 listings starting at $2,219
Used Volkswagen Jetta
867 Great Deals out of 36,431 listings starting at $1,494
Used Audi A8
62 Great Deals out of 1,553 listings starting at $3,800

Used Cars for Sale

2018 Audi A4 For Sale
10 Great Deals out of 1,094 listings starting at $27,800
2017 Audi A4 For Sale
29 Great Deals out of 573 listings starting at $17,998
2016 Audi A4 For Sale
18 Great Deals out of 565 listings starting at $15,498
2015 Audi A4 For Sale
22 Great Deals out of 518 listings starting at $10,990
2014 Audi A4 For Sale
14 Great Deals out of 402 listings starting at $9,555

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.