Nick, I would start at the beginning to get your pump running or prove it's broken. There are 4 or 5 fuses and at least 3 relays on this system. The pump is goverened by a 30 amp fuse in the electrical box beside your washer bottle. I would start there. Ohm the fuse, there sometimes hard to see if there blown. If good check the voltage with key on at the fuse socket. If you have power there try swapping a fuse from the electric center by the rt fender. I think one of the cooling fans is 30 amps. Check all the other fuses including the one in the glove box.

If that all checks out ok then we will go to the relay on the side of the PM and see if there is something wrong there. That relay can be tested along with the power in and power out and the pressure switch can be bypassed.

Try the fuse and let me know.

Jud

I don't have an OHM meter/tester.  I think when I get home today I'll just try swapping the relay from my old PMIII and see if that will let the pump turn on.  If not, I dunno...

the fuse has a clear window on top of it, you should be able to see that one pink fuse for the pump motor easy. 30 amp one. I think they're slow-blow fuses, cost like $2.50 each. so get em from the J/Y. bet thats all it is. If it keeps blowing the fuse the pumps going out. keep an eye on it when the system primes itself when you first hit the key.

Quote from: GangstGP on December 14, 2006, 12:04:35 PM
the fuse has a clear window on top of it, you should be able to see that one pink fuse for the pump motor easy. 30 amp one. I think they're slow-blow fuses, cost like $2.50 each. so get em from the J/Y. bet thats all it is. If it keeps blowing the fuse the pumps going out. keep an eye on it when the system primes itself when you first hit the key.

Ok I'll check those fuses also.

oh wait, I guess Jud covered that already  :icon_redface:  yea, what Jud said. :icon_cool:

Quote from: GangstGP on December 14, 2006, 02:52:30 PM
oh wait, I guess Jud covered that already  :icon_redface:  yea, what Jud said. :icon_cool:

Ha, yea I thought I heard an echo. :laugh:

Jud

I checked ALL of the fuses that are brake related, NONE are blown, I even swapped the 30 amp one out like you said, Jud.  The only thing fuse/relay I haven't swapped out is the relay ON the PMIII.  Pump still refuses to run.

I just replaced the relay that is mounted on the side of the PMIII with a known good relay off my other PMIII, and the pump still refuses to run.  :icon_rolleyes:
What should I do next?

What should I do next?  Any ideas?
Thanks everyone

<------------------------Glad I blew up the engine and not reparing PMIII Brakes  :icon_eek:

I would take the unit out (maybe do it while its in?) hot wire the positive and negative and see if the pump will run.

try the other one too.  touch the wires with a power drill battery or something. thats how I test window motors in the junkyard.

Hotwire it?  HOW??  I need an explanation.

Why don't you try the pressure swich out of the the PM you got the relay from. You can see if the pump will run by applying 12v to the white wire on the relay plug. Hope you didn't put the relay back on the pump.

My neighbor just had an idea- maybe the system is SO pressurized and full of air, the system thinks there is enough pressure that the pump doesn't need to run.  I'm gonna pull the brake lines out of the master cylinder like you said and see if anything comes out.

take your PMIII you took out and hook up the power drill battery just like I said.  the pump should run momentarily while you brush some hot wires across the terminals of the plug. If it dont run then the pump dont work. its just to verify that the pump is fried and its not something else