Would greatly apreciate any advice on this.

My work van (2002 Dodge Ram Van 1500 - 80k miles) is giving me a lot of
trouble. In the morning when I start it up, it runs perfectly fine for
about 15 minutes. Then it abruptly starts stalling. Once it starts
stalling, it stalls at almost every red light. If I'm in heavy traffic
where a lot of stop and go is required, it'll stall many times. In a
parking lot, I sometimes have to restart the van a few times to get in and
out of a parking space. Right before it stalls, I hear a clicking noise
down towards the left side of the dash. If I'm driving above 30mph or so,
the van seems to jerk as if it was trying to stall, and the oil level
guage drops all the way to the left as if the van was shut off. I hear a
clicking noise down toward the left side of the dash when this happens,
too. It always starts right back up - usually the oil guage returns to
normal, and sometimes it remains buried as if the van was shut off - even
though the van runs fine and does not overheat.

I took it to a mechanic who charged me $100 to hook it up to some sort of
sensor, only to tell me that there were no faulty codes detected, but he
thought it might be the ignition switch - which he replaced. However, the
problem continues. So, I stopped by the Dodge dealership and they said
that the sensors they use there are much more hi-tech and that it would
definitely pinpoint the problem, but it's going to cost me $150.

Looking under the hood, I placed my fingers on the relays by the battery
as someone started the van. As it stalled, I noticed 2 things: 1. The
engine seems to slow down a little right before it stalls...... 2. The
relay under one of my fingers (ASD) clicks right before and right after it
stalls. Could a faulty ASD Relay be the cause of this?

I know I should just take it to a mechanic and get it fixed, but I really
don't have the money for it right now. So, please... any advice at all.

Thanks.