How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ron Your Own Question
Ron
Ron, ASE Certified Technician
Category: Honda
Satisfied Customers: 33439
Experience:  ASE Certified Tech 34 years.
7276279
Type Your Honda Question Here...
Ron is online now
A new question is answered every 9 seconds

98 CRV, new AC compressor with clutch, new pressure switch

Customer Question

98 CRV, new AC compressor with clutch, new pressure switch but clutch pulley will not engage unless we jump the relay??
JA: Has the clutch been slipping? Are you having any trouble shifting?
Customer: Actually put 2 new units in as the 1st one was determined to be defective from manufacturer
JA: Are you fixing your CR-V yourself? What have you tried so far?
Customer: Not talking about the transmission/clutch I'm strictly talking Air conditioning man
JA: Anything else you want the mechanic to know before I connect you?
Customer: Clutch pulley bearings went bad & was making a horrible noise
Submitted: 2 months ago.
Category: Honda
Expert:  Ron replied 2 months ago.

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

Expert:  Ron replied 2 months ago.

Dose the system cool once the relay has been jumped?

Is this a Manuel system (knobs) or an automatic (buttons)?

Customer: replied 2 months ago.
it begins to cool right away
Customer: replied 2 months ago.
Manual push button selector for AC
Customer: replied 2 months ago.
Push button AC selector with manual fan knob
Customer: replied 2 months ago.
Are you a Honda mechanic? This is a 98 CRV
Customer: replied 2 months ago.
Hello Ron are you there??
Customer: replied 2 months ago.
Ron I've paid the fee & now I expect some answers
Expert:  Ron replied 2 months ago.

Yes Im here . The problem you are having can be caused by any of the following,

Customer: replied 2 months ago.
we checked (with the relay in) there's no power to the red wire plugged into the AC compressor that runs clutch from relay
Customer: replied 2 months ago.
But when we pull the relay & jump it we get cold air & the clutch engages
Expert:  Ron replied 2 months ago.

You should have power (key on) on the 2 pins at the relay from fuse 56 (20 AMP) and the ECM (computer ) supplies the ground to energize the relay . Once the relay is energized you should have power out to the clutch. Do you have power at both power pins at the relay?

Customer: replied 2 months ago.
Expert:  Ron replied 2 months ago.

Okay dose the relay energize if you ground the red/black wire from the ECU?

Customer: replied 2 months ago.
Not sure, we haven't checked that. Is that the computer & is it under the dashboard?
Expert:  Ron replied 2 months ago.

Yes but you can ground the wire at the relay. Try grounding it and see if the clutch kicks on.

Customer: replied 2 months ago.
Ok I think we found it on the passenger side under dash, does that sound correct?
Customer: replied 2 months ago.
Ok going back up to the relay & trying to ground there
Expert:  Ron replied 2 months ago.

On your the ECU should be in the right side kick panel.

Customer: replied 2 months ago.
Does that mean pulling the fuse box out under the hood??
Expert:  Ron replied 2 months ago.

No, you can slip a small ground wire in under the relay and ground the pin at the relay.

Customer: replied 2 months ago.
Am I supposed to pull the fuse box under the hood
Customer: replied 2 months ago.
Do you mean the AC relay or the ECU relay?
Customer: replied 2 months ago.
I think you mean AC relay?
Expert:  Ron replied 2 months ago.

If you look at the wiring diagram I sent you , you will see the AC clutch relay is not under the dash. Its located in the under hood panel. The AC clutch relay is the relay Im taking about.

Customer: replied 2 months ago.
Vehicle running with AC selected correct?
Expert:  Ron replied 2 months ago.

Yes correct.

Customer: replied 2 months ago.
We grounded it from the relay to the battery and it did not activate the clutch
Customer: replied 2 months ago.
Clutch did not activate
Expert:  Ron replied 2 months ago.

Okay are you sure you have power at both power pins (key on)?

Customer: replied 2 months ago.
You mean power at the relay pins correct?
Customer: replied 2 months ago.
We did check that as far as I know and yes we did have power
Customer: replied 2 months ago.
We checked it to make sure we had the right ground for red/black wire before grounding to the battery
Expert:  Ron replied 2 months ago.

Okay if you have power on both pins and a good ground from the ECU then the relay should kick in and send power out on the red wire. Are you sure the relay is not bad?

Customer: replied 2 months ago.
We swapped that relay twice with 2 other same amp relays, cooling fan relay & condenser fan relay & still didn't activate the clutch
Customer: replied 2 months ago.
Expert:  Ron replied 2 months ago.

Okay go back and make sure you have key on power on both power pins and a good ground on the the red/black wire and power out on the red wire to the clutch. If you do then the clutch should run.

Customer: replied 2 months ago.
engine running with AC selected right
Expert:  Ron replied 2 months ago.

Yes correct.

Customer: replied 2 months ago.
Just turn key or has to be started with AC on? Just turn key right cuz all we're doing is checking for power & ground correct
Customer: replied 2 months ago.
Engine running or not?
Expert:  Ron replied 2 months ago.

Yes start the engine, turn the AC on and then check the powers and ground at the relay and out of the relay to the clutch on the red wire.

Customer: replied 2 months ago.
Do we pull the relay for this check or leave it in?
Expert:  Ron replied 2 months ago.

You only pull the relay to check the two power pins, if you have power on them the place it back in and back probe it to check the ground and power out.

Customer: replied 2 months ago.
I'm assuming that means taking the relay out to check the pins & then
Expert:  Ron replied 2 months ago.

Yes just the two power pins, the relay dose not need to be in place to check them.

Customer: replied 2 months ago.
Then replace & check red power wire out of relay & red/black wire as well
Customer: replied 2 months ago.
With relay out we have power & ground to pins
Expert:  Ron replied 2 months ago.

Yes verify you have power on both power pins, then reinstall the relay and check for ground from the ECU on the red/black wire and power out on the red wire to the clutch.

Customer: replied 2 months ago.
we do this at the box in the engine compartment not the ECU panel in passenger side kick plate correct??
Expert:  Ron replied 2 months ago.

Yes you do this at the AC clutch relay.

Customer: replied 2 months ago.
Do we need to pull the fuse box apart to see these wires?
Customer: replied 2 months ago.
to verify the color & ground?
Expert:  Ron replied 2 months ago.

If you can not back probe them at the relay then yes, pop the fuse box up and access them from underneath.

Customer: replied 2 months ago.
I didn't think it required that but apparently we have to pull the entire box apart which is a real pain in the ass
Expert:  Ron replied 2 months ago.

You need to do what ever it take to access the pins with the relay in place. How else are you going to know if there is ground in and power out.

Customer: replied 2 months ago.
Ok so we did back probe and when we did the ground it activated the clutch
Customer: replied 2 months ago.
We now have the entire box torn apart & can't really tell much from the bottom, not seeing a red/black wire?
Expert:  Ron replied 2 months ago.

You should be able to trace it in from the harness. It looks just like the wiring diagram I sent you.

Customer: replied 2 months ago.
I see 2 black wires with red tracers & a red one with a silver tracer
Expert:  Ron replied 2 months ago.

Yours should match the wiring diagram.

Customer: replied 2 months ago.
Do I need to understand what you mean is it BLACK with a RED tracer or RED with a BLACK tracer?? We are seeing 2 black with red tracers and one has 1 silver hash & the other 2 silver hash marks?
Expert:  Ron replied 2 months ago.

It should be red/black witch usually means its red with a black tracer.

Customer: replied 2 months ago.
You told me "Red/Black" wire
Expert:  Ron replied 2 months ago.

The diagram shows it as back/red , have you looked at the wiring diagram?

Customer: replied 2 months ago.
We absolutely do NOT have one single "Red/Black" wire, they again are BLACK WITH RED TRACER
Customer: replied 2 months ago.
Of course we are looking at it!
Expert:  Ron replied 2 months ago.

Okay Im not sure where to send you now, the system should match the factory wiring diagram. If you would like I can open the post back up for you. Perhaps someone else has something else to offer.

Customer: replied 2 months ago.
Umm....sir 3 maybe 4 times you told me "red/black" that is in fact incorrect it's Black/Red.
Customer: replied 2 months ago.
Again we have 2 wires that are black with red tracers
Expert:  Ron replied 2 months ago.

Yes, the black wires with the red tracers should be the correct color.

Customer: replied 2 months ago.
a solid red wire
Expert:  Ron replied 2 months ago.

It could be both, if you look at the bottom of the panel where the relay goes in you would be able to trace it from there.

Customer: replied 2 months ago.
we have power at both pins at relay but when relay replaced, car running, AC selected, no power from red wire to clutch until it was grounded (relay in, back probe the ground) and clutch kicked on?
Expert:  Ron replied 2 months ago.

Okay the ground is supplied from the computer and if the computer is not grounding the relay it will not engage. Have you by chance scanned the system to see if there are any fault codes setting for the AC?

Customer: replied 2 months ago.
I watched the clutch while my buddy back probed the ground and every time it activated the clutch
Customer: replied 2 months ago.
we have & there are no fault codes for the AC
Expert:  Ron replied 2 months ago.

Okay if everything else checks out okay that usually means the problem is with the ECU.

Customer: replied 2 months ago.
again to be clear we have no fault codes for the AC
Expert:  Ron replied 2 months ago.

Okay then the ECU is not supplying a ground to the relay and if you have done your testing correctly that usually means the ECU is at fault.

Customer: replied 2 months ago.
There is ground continuity from the ECU to the fuse box on the black/red wire with the double hash....as far as the single hash black/red wire we have continuity from fuse box to battery and from fuse box to engine
Expert:  Ron replied 2 months ago.

Okay are you getting a ground from the ECU to the relay?

Customer: replied 2 months ago.
Running or not?
Customer: replied 2 months ago.
We've been doing these ground continuity tests with engine off
Customer: replied 2 months ago.
Without running we are getting continuity from ECU to fuse box on the ground
Expert:  Ron replied 2 months ago.

Yes I under stand that but is the ECU sending a ground to the relay with the system running?

Customer: replied 2 months ago.
Ok we'll check now with it running
Expert:  Ron replied 2 months ago.

Okay, the ground to the relay comes from the ECU to ground the relay.

Customer: replied 2 months ago.
we get ground from ECU to relay with engine running & AC selected
Customer: replied 2 months ago.
We have both ground & continuity from the ECU engine running AC selected
Expert:  Ron replied 2 months ago.

Okay then the relay should engage and the clutch should kick on.

Customer: replied 2 months ago.
That's basically our original problem, the clutch was not activating unless we jumped the pins when the relay was out
Customer: replied 2 months ago.
When jumping the pins the clutch kicks on & we got fairly cold air
Expert:  Ron replied 2 months ago.

Well if you have power on both power pins and a good ground from the ECU to the relay then it should energize and send power out to the AC clutch. Are you sure you have a good ground from the ECU to the relay?

Customer: replied 2 months ago.
we do have both continuity and a good ground with a test light with car running , AC selected from ECU to fuse box
Customer: replied 2 months ago.
Can it possibly be the main fuse box?
Expert:  Ron replied 2 months ago.

Its not likely if you have power in and out at the back of the panel with the relay in place.

Customer: replied 2 months ago.
Customer: replied 2 months ago.
what are we looking at then?
Expert:  Ron replied 2 months ago.

As I have said, you need power at the two power pins, and a good ground from the ECU to the relay and if you have this, the relay should power on and send power out to the clutch. Are you 100% sure you have these?

Customer: replied 2 months ago.
We took the relay apart, checked it and the coil winding is swollen, furthermore it doesn't actuate the clutch unles you depress the switch on the relay, therefore we think it's a bad relay??
Expert:  Ron replied 2 months ago.

I am pretty sure I asked you about the relay some time back. have you tired a known good relay?

Customer: replied 2 months ago.
Well that's the issue, we swapped 2 relays but still couldn't get the clutch to activate but when we pulled the original relay apart it shows signs of it being bad & you physically have to depress the switch to engage clutch
Customer: replied 2 months ago.
Ordered new relay , waiting for delivery
Customer: replied 2 months ago.
Just arrived now and installing
Expert:  Ron replied 2 months ago.

Okay if you have power at both power pins and a good ground from the ECU the compressor should kick in.

Customer: replied 2 months ago.
New relay no AC
Expert:  Ron replied 2 months ago.

Okay are you 100% sure you have power at both power pins and a good ground from the ECU the compressor?

Customer: replied 2 months ago.
ECU to compressor or ECU to relay?
Expert:  Ron replied 2 months ago.

ECU to the relay, the ECU supplies the ground to the relay just like its shown in the wiring diagram.

Customer: replied 2 months ago.
With key on He put a test light to the neg terminal on battery and to the ground relay when it was in place, also to the power pins there's 4 pins- 2 power & 2 grounds correct? I have to be honest my automotive electrical skills are very, very basic & I'm not confident that the other guy knows what he's doing, he says he does but I'm not convinced.
Customer: replied 2 months ago.
Please give me step by step instruction of how & where to check this Power & ground as well as with or without running & with relay installed or removed ?
Customer: replied 2 months ago.
I will show him your step by step instructions
Expert:  Ron replied 2 months ago.

Im afraid I would agree with the testing skills , no offense. At the relay there should be 2 pins with key on AC on that should read power, and to energize the relay (turn it on) the ECU (computer) supplies the ground on the Black/red wire. Once the ECU supplies the ground then the relay should kick in (turn on) and supply power out of it on the red wire to the AC compressor clutch.

Expert:  Ron replied 2 months ago.

What did you figure out on your retesting?

Customer: replied 2 months ago.
Went through everything & I mean everything again and still the clutch won't engage! Changed relay twice just to make sure, changed dryer, evap the entire system & re charged! Still nothing?
Customer: replied 2 months ago.
This is the second new compressor with clutch assembly that's been installed in the last 2 days along with 2 new relays & a new accumulator/drier
Customer: replied 2 months ago.
Scan check on computer checks good
Expert:  Ron replied 2 months ago.

As I have said, if you have power at the relay on both power pins and a good ground from the ECU then the relay should engage. Did you ever decide if you have power and ground at the relay?

Customer: replied 2 months ago.
Would you advise using a test light or a multi meter to run these checks
Expert:  Ron replied 2 months ago.

You can use either one, the volt meter work best for checking voltage though.

Customer: replied 2 months ago.
He's been using a test light and I haven't seen him put a multi meter on it yet. I understand the test light show your ground and I'll probably show your power as well but it's certainly not going to give me the numbers
Expert:  Ron replied 2 months ago.

That is correct, it will not show you the actual voltage and thats why a volt meter is best for testing.