Ok, My blower has an intermitent problem.
When I am driving (moving at RPM's above 1000) the blower motor works fine. Sometimes when i come to a stop, (like at a stop light) and i am in drive with my foot on the brake the blower will just stop. when it does this i can hear the relay under the dash on the drivers side clicking away. So i changed the relay and it is still doing this? The A/C blows cold but the blower quits working when i need it most - at stop lights.... Anyone have any ideas about this?

Mine does the same thing sometimes, but mines a manual. I notice mine only does it when the rpms drop below a certain point. My rpms sometimes bounce a little when coming to a stop. When it goes below a certain point, the blower quits, but as soon as the rpms go above that certain point, the blower comes back. My theory is that the computer is shutting down accessories to try to keep the engine running. Either that or the relay that turns the blower on once the engine is running ends up believing the engine has been turned off and it loses power momentarily.

Richard <img src="/forums/images/graemlins/patriot.gif" alt="" />

Sound like low voltage to the blower relay. Bad ground wire, weak battery or alternator things to check out. HTH

<img src="/forums/images/graemlins/zombie.gif" alt="" />

You have A/C and you're complaing??? <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

Ugh, to have your problems.... 90degrees today...100% humidity. Canandian friggin' Trooper w/no A/C, intermittent or otherwise.

Good luck. <img src="/forums/images/graemlins/smile.gif" alt="" /> I'll try to feel sorry for ya.

Dana

Well, I had to refurbish my whole A/C....
which encompassed replacing cracked lines with new ones from car-part.com ($30)...flushing with brake cleaner and changing every o-ring and componenet in the system (except the evaporator and condensor)....

This site sells retro A/C kits for troopers not equipped with A/C for $711.00...... may be an option for you?

http://www.ackits.com/index.cfm?fuseaction=FindAKit

I'd buy a multimeter and check the voltage across both pairs of blower relay terminals while at idle, and again at medium rpm. If the relay is clicking, I'd agree with what's been mentioned as a battery, alt or wiring problem.

If you want to put A/C into a trooper without it , its not really that hard.Just find a donor vehicle with it , in my case its out of my 89.I have it all ripped out and ready to put in the 90.I just need to get that kit that redoes the seals to convert it to the new refigerant , and load her back up.Its a matter of taking out the A/C rad in front of the truck rad , the drier and 2 lines , the compressor , and not sure what to call the part thats piped into your ducting inside the truck.All in all , it took me about an hour to rip it all out.And while I did that , I also took out the cruise control , doesn't hurt to have a spare <img src="/forums/images/graemlins/smile.gif" alt="" />

same problem here. I have changed out all of the relays associated with the blower. I also noticed that when the blower doesn't work, the A/C compressor doesn't either. I have been told to change the resistors that go to the blower assembly but have yet to find one that I can use. I have pretty much just givin up on it. I did find though that if you put one of the gray relays from under the dash into the relay plug under the headlight your blower will work just fine, however it won't shut off when you turn off the key and it will also run down your battery.

If anyone has ever figured out this problem successfully I would gladly pay for the solution <img src="/forums/images/graemlins/scared.gif" alt="" /> It has driven me crazy for almost a year now. The local shops either won't even touch it or they want more than the Trooper is worth to fix the problem

I have noticed the same thing on my troope also
(compressor turns off when blower turns off).

I had my battery and alternator checked by an alternator specialist. the alternator is putting out and the battery is
holding a charge.

There has to be a solution to this?

I have noticed that in addition to the above mentioned problem ,when at idle under load (in drive with brakes applied) or in park the compressor clutch will slip at idle. If I kick up the idle the cltuch will engage. HAs anyone ever changed an A/c compressor clutch with the compressor on the vehicle?
What tools are needed?
BTW, this is the GM R4 compressor and clutch.