Hello all. Long time listener first time caller. For starters i have a 1994 Ram 2500LD 5.9, 175,000 miles stock as far as i know. I bought the truck about a month ago from a kid going to college to be a mechanic. I searched the forum for most of these answers and think my situation may be unique to what iv found. If these are repeat questions i appologize.

1) When i bought the truck the kid told me that if i honk the horn the compressor for the A/C quits. After asking the local shade tree mechanic i checked the grounds on the horns, checked the fuses and tried to honk the horn. Sure enough the compressor quit and i blew the fuse for the horn. Then i replaced the fuse and compressor still dont work. Any ideas why this is?

2) Sometimes when i click my dimmer switch from bright to dim or vise versa i lose headlights. Do you think its the dimmer switch or the light switch in the dash?

3) The engine is kind of doggy not as much power as i think it should. My first thought was plenum gasket. When i brought this up to my mechanic he said the way to check it to cover the crankcase vent hole and the air intake with your hand. If you have positive pressure at the vent hole the gasket is good if it pulls in its bad. He checked it and said it was good. I havent read this way of testing on here. Does anyone know if it is accurate?

Hate to be a pain in the a** on the first post but any answers will be greatly appreciated.

 

There is a factory test for the plenum but if I recall correctly it's really only useful if the plenum is WAY blown.

Best things to do is pull the throttle body off, use small dental like mirrors and look for oil pooling, some oil is to be expected however.

2nd best thing to do and most annoying is to pull the intake manifold itself and see if the gasket is blown.

If and/or when you replace the plenum it's best to replace the PCV valve as well, along with the O2 sensor and catalytic converter

 

I would bet if you address the plenum gasket and then do a fresh tune up with spark plugs and everything, the engine will wake up quote nicely

 

Not to mention the timing set. The morse style chain that they come with from the factory stretch out very nicely. Putting a double roller set on my truck was one of THE BEST 'fixes' for gaining back lost power.

 

Yes this too! A double roller is less then 50 bucks. A tensioner is not really necessary IMO, although nice to have

 

Here is a link to factory service manual https://dodgeforum.com/forum/2nd-gen...e-manuals.html
that will help trace down electrical issues you are having.

Dave

 

welcome to df.

for the electrical, i'd guess you have at least 2 different problems. for the horn fuse blowing, my first guess would be to check the wiring glob at the tilt wheel joint. remove the covers around the column with a long skinny torx, about a #20 or #25, and a lot of patience to unclip the top/bottom halves. once you get there you can see all the wires. while you're there, for headlights - i'd replace the multifunction switch. you can get a new one with lifetime warranty from advance (with online discount codes) for under $50. i'm stumped by the compressor quitting. check the service manual section 8 wiring diagrams to see which wires, fuses, relays are involved in that circuit.

for the engine, you disconnect/cap the valve cover air vents to the breather and pcv and check for suction(vacuum) at the valve cover grommets. but - based on history, you can pretty much bet that any 5.2/5.9 with a steel belly pan is leaking, as well as the timing chain is shot and the front and rear crank seals are leaking. the best bet is to simply check the belly pan with a magnet on a stick and verify its steel(stock). then buy a replacement on ebay from our forum member, new timing chain, water pump, seals, gaskets, etc and plan a top end/front end repair and do it all at once. check compression first. if ok, proceed and it'll buy you another 100K miles.

 

Thanks for all the advice ill repost when i have updates.