This just happened to my Dad's 1998 GMC Safari...
Firstly...
Check the hard vacuum line as previously noted by others.
If that's ok, then take off the intake pipe and spray brake clean into the throttle body while trying to crank it.
If it starts.. then you have a fuel related issue, if it doesn't start then you have an electrical related issue.
Our van did not start after trying to use brake clean.
Take off the console inside the vehicle's cab and get at the distributor.
Usually people noted that the ICM (ignition control module, inside the distributor) was the main issue here, but on our van, the distributor and wires looked brand new so it was probably recently changed (we got this van 5 months ago), so I assumed the spark plugs were also changed at the same time.
We unplugged the connection from the coil to the distributor, tried to crank it, and no spark was being generated, boom, got a new coil and starts up fine.
Just takes a bit of trial and error.
Do you know anything about automotive electrical system's ? How to use a wiring diagram an a DVOM - digital volt ohm meter to test electrical circuit's ? Looking at wiring diagrams to see if these systems share a common ground point or power supply would be the place to start . Free wiring diagrams here http://www.bbbind.com/free_tsb.html Enter vehicle info year , make , model . Under system click on body & accessories ,then under subsystem click on power windows . click the search button then the blue link . looking at the diagram i see a 30 amp circuit breaker powers the windows , wouldn't think that to be the problem . Check out the ground # at the bottom right . G-103 or 105 . Check some of the thing's not working . Go back to the first part an click on HVAC under system . Check the blower motor circuit . This has a different ground . probably not that ! Checking the instrument panel electrical harness an connector's . Go to electrical distribution under system , then under subsystem click on power distribution . Look an see where all these system fuse get power from , a main fuse , ignition switch or a relay etc.... Check to see if B+ voltage is at the power window circuit breaker when not working . If not , problem is up stream from there . Watch these video's Electric Testing Techniques You Need to KnowMastering Voltage Drop Testing with Pete Meier and Jerry Truglia
Testing the electrical circuit's is the way to find the problem . Hope i explained this good enough . Good luck & god bless
There are usually around 4 to 6 screws around the instrument panel to remove it.
Be careful here, I've seen many wires broken doing this removal.
Hope this helps.
The resistor is not the likely candidate for a fuse problem. There is either a short in the electrical wiring to the blower motor, or the blower motor itself is faulty, causing the fuse to blow. Disconnect the blower motor from the circuit and try turning it on. If the fuse doesn't blow, it's probably the motor.
there is a blower relay circuit board located right by the blower motor which sounds like your problem to me i've worked on several that had the same type problem and thats what it was. the two blower motor wires will plug into it and there are two screws that hold it on
to me it sounds like a loose wire may be exposed to metal touching that one point or another and it's definitely an intermittent problem and that's what it sounds like to me
Listen closely for a hard "click" sound at the starter motor when turning the key switch for crank. If it clicks, check the contacts of the thick cables at the starter, battery and grounds at the chasis and engine. If it doesn't click, the the problem might come from the key switch or its wiring.
you can try flicking the throttle, it may release. check for kinks or any other damage to the accelerator cable. there may even an adjustment on the throttle body, aproximatly 800 rpm is acceptable
Check the wheel bearings for serviceability. Check the pad thickness on the discs. I suspect a failed wheel bearing allowing the disc rotor to touch the ABS sensor ring and the calipers.
you have a SHORTED, CONDITION, you need to inspect all wires within this circuit, including all grounds. are all your connections right ? with engine running is your battery showing 12 to 14 volts, is your starter connected properly, reinspect all wiring in this cicuit, are your battery cables in good shape ? make sure no other wires are touching wires in this charging circuit . have a parts store check the charging circuit for you . have them check the battery, and the alternator, one dead cell in battery can cause your problem, also even a new alternator can be bad !!!