marlinspike

Thanks man. I'm going to buy some batteries for my flashlights and try that stuff out in a few.

I'm actually thinking you might be on to something by saying to check the connector on the clutch assembly first - when changing the p/s pump I got a bunch of p/s fluid on it...might have killed it.

And yeah, aux fan was one of the first things I checked. Works.

Fabrik8

Yep, time for a multimeter and some probing. It should be easy to find.

marlinspike

Ok, no volts at connection. So now I put the black wire of my multi meter on the ground of the connection and the red one on the battery pos?

marlinspike

So...what if there is power at 30 but jumping 30 & 87 does nothing?

marlinspike

Power wire makes 7.8Mohms with battery ground. What mean?


Also why did ground wire to batt pos give me a small spark when I touched wire on my multimeter to the batt pos for the firs time, but doesn't do it any more?

marlinspike

Ok, well I was wrong about jumping it not doing anything. I expected the additional load from jumping it to noticeably change the idle, but I guess without the rest of the relay to control the idle when it's not jumped, the load doesn't do much (1100rpm in P isn't going to be hurt too much by the A/C I guess). When I jump it the front part of the compressor starts to spin. This doesn't happen with the relay.

So a bad relay I guess?

Fabrik8

That means you should set the multimeter to DC voltage instead of resistance.

marlinspike

LOL. But he said measure resistance???

At any rate, I'm thinking the jumping of pins 30 and 87 proved it's the relay? Weird that the clutch engaging didn't slow the engine down, but it definitely engaged when I did that and definitely didn't engage with the relay installed.

So...does that prove it's the relay? Because I'm going to order one used off ebay if it does (wtf relay, why do you cost close to $200 new?)

Fabrik8

That's what it sounds like, yes. There isn't any way to test resistance on a circuit that's powered, so if you want to do a continuity check then you need to pull the fuse or disconnect the battery. You can also test voltage at various points around the circuit, and that can tell you a lot but will not necessarily tell the whole picture either because circuits with no current running through them won't have any voltage drop across them.

If you jumpered across 30 and 87, and the compressor engaged, that doesn't necessarily say that the relay is bad. It could say that the relay isn't getting activated. One side of the coil goes to ground. If you remove the relay, you can check continuity between that side of the coil and ground. You can also check for voltage at the other side of the coil (the side with the switches and everything on it). You should have no voltage when the compressor clutch is NOT supposed to be engaged. When the clutch IS supposed to be engaged, you should see 12V at that coil terminal.

So this is the point of looking at the voltage at the relay coil terminal:
If you DO have voltage at the coil when you should, the relay is obviously not turning on when it should, and therefore the relay is bad.
If you DON'T have voltage at the coil when you should, something else is the problem instead of the relay. The relay can't turn on if it isn't getting controlled properly.

If the relay isn't the problem, you can do the same test with every component upstream from the relay until you find out which one is bad. You can also start from the battery end and work toward the relay, and find the same problem. Which method is faster depends only on which end of the chain the problem is closer to, so either method will work. Finding out which components are working properly helps find out which one is bad through the normal process of elimination, so nothing new there.

marlinspike

*googles continuity*
*wonders what the coil is* (realizes you posted about this earlier).

FUCK YOU ELECTRONICS, I DON'T UNDERSTAND ANY OF THIS!!!!!! WHY CAN'T THIS SHIT WORK ON VACUUM OR HYDRAULICS???????????