oldpro

got my airconditioning up and running a month ago and everything seemed fine . the other day I turned it on and nothing . I cked for code as the fsm says and it shows no codes . here is what it ddoes . I turn it on and the motor seems to drw down like the compressor is coming on the cooling fans come on but the fan for the aircondition to blow air in the car doesn't come on . I unfortunately don't have the fsm wiring book for my car to ck out the switches . how do I test those to se if one of them went bad . I double cked to make sure I had a charge and the gauge that one gets with the refill set up says 40 on the gauge . thanks for any guidance .

Kevova

Is there 12 volts at blower motor connector? If so you may just need a blower motor. good luck.

70ZZ3 96LT4

I checked a blower motor once by removing the power wire and connecting the positive clip of my battery charger (not a powerful battery charger) to the terminal and the battery charger negative clamp to ground and the fan motor worked just fine.

antfarmer2

Have you checked the fuse?

oldpro

I found a 5 amp fuse under the cooling system tank but it says there is a 30 amp fuse on the engine compartment bulk head on the drivers side cant seem o find that one ????///

Cliff Harris

Too many unknowns here to get specific...

What year is the car? Everything changed in 1990, so it makes a big difference.

Does it have C60 (manual) or C68 (digital) HVAC system?

antfarmer2

On my 94 there is a fuse case in front of the battery

WVZR-1

You've asked this question in 2 different C4 sub-forums and have failed to mention the year. The year matters certainly when you're looking for OR requesting help.

"oldpro" is maybe a newer userid that you've created - I've seen a couple posts that seem to indicate you've used many maybe for a few years.

oldpro

the car is a 90 I did mention it on the other forum and it also is a zr1 . . I have tested the blower motor and it works but no power to the plug I need to find the 30 amp fuse before I can go on and cant find it . I need to know where it is located . I found a 5 amp fuse under the coolant tank . but cant find the fuse block 1 which is suppose to be allocated on nthe bulkhead in the engine compartment . also it is a automatic system .

oldpro

yes I have had a few different I ds over the years I am not very computer savy and haven't until very recently figured out how to recover my id so I just created a new one so I could get on the forums.i am just a retired fella trying to either give help where I have knowledge or get help when I have no knowledge I wish the city colleges here would have night classes on computors but it is a small town and they don't offer anything . I mean nothing ill about doing it that way.it was the only way I knew how to do it till someone showed me how to do it . sorry

WVZR-1

A '90 doesn't have a fuse block at or near the LH firewall. There's the fuse that you found and the balance of the fuses are contained mostly in the fuse pane that's right side of dash. There are fusible-link exceptions but that you need to be concerned with? Don't know.

A '90 is also a potential C60 (manual) or C68 (automatic) AC option and the diagnostics are all different. The fuse that you mentioned finding hints it's a C68 system but ............

oldpro

I guess I have the c 68 system so does that mean I have that 30 amp fuse . do you know where I can buy the electric section of the fsm manual for a 90 .

Hooked on Vettes

If the 40 psi reading is with the engine off, (static pressure) that's to low and the compressor clutch won't engage. You have a refrigerant leak but that won't prevent the blower fan motor from operating.

You need a test light or volt meter.
On top of the evaporator housing are two electrical plugs.

One plug has a Red wire. That's 12 volts to power the blower control module and hot all the time.

2nd plug has three wires.

Dark Green/Yellow varying voltage depending on the fan speed setting.
a 1 in the LCD would be slow speed.
a 10 would be high fan speed. This is the control voltage sent to the Blower Control module from the HVAC Programmer.

Purple wire is the voltage to power the Blower Motor and comes from the Blower control module.

Black wire is Ground.

Unplug the two pin connector at the Blower Motor.
Connect red meter test probe to the Purple wire.
Connect the black meter test probe to the Black wire.


Turn ignition On.
Press the Auto button. 2nd button to the right on the bottom row of buttons. Auto LED below the button should light.

Press the Fan arrow up button until you see 10 displayed in the LCD.

You should measure at least 12 volts on the meter.

If you do and the blower motor fan isn't running the fan motor is bad.


If you read zero volts.

Turn ignition Off. (RECONNECT THE BLOWER MOTOR PLUG).

Remove both electrical plugs on top of the evaporator housing.

Place your Black probe on the four pin connector Black wire. (Ground)
Place your Red probe on the Red wire.

Should measure 12 volts.
If zero volts the Fusible link is blown. Its located under the battery
bolted to the battery jumper block.

If you measure 12 volts
Turn the ignition On.
Press the Auto button if it isn't lit.
Press the fan arrow button until you see 10 in the LCD.

Move your red probe to the Dark Green/Yellow wire.
you should measure around 7 volts DC.

If no voltage could be the AC programmer is bad or the Dark Green/Yellow wire is bad.

If you do measure 7 volts and the blower fan is not running the Blower Control Module is bad. The Blower Motor Control module is located inside the evaporator housing. Remove three or four small bolts and it will lift out of the evaporator housing. DO NOT REMOVE THE TWO SMALLER BOLTS OR THE Blower Motor control module will fall into the housing.

oldpro

wow thank you so much for taking the time to go thru it step by step and where to put the wires on the meter . you are so kind /.I will go thru the proceedures and report what I found .

Hooked on Vettes

I responded to your question and there is no way that voltage is correct.

oldpro

om thank you so much for all your help. I now have airconditioning. it was a pleasure to talk with you . when I get to bill I will see what I can do for you to repay you for all your kind help . have a great weekend