it depends where it is. did they say?
for example, you can crawl under there under the exhaust while your helper plugs the exhaust pipe end with a rag.
if everything is all tight, it'll usually load up real quick, if there is a leak there won't be much restriction and you often can *hear* where the leak is -- follow your ears.

1992 sohc trooper 3.2l v6 automatic . . . as is

i love a good intermittent electrical challenge. . .especially when it's someone else's.