Mechanics

FUEL PUMP RELAY NOT INGADGING FUEL PUMP ON MY 98 1500 WOULD IT BE THE COMPUTER OR SOMETHING ELS

1989 Dodge Ram • 130,000 miles

I can run a hot wire to pump and it works and I can ground the relay and it works I have 2 codes 1 is po 0443 which is perg controle valve circuit the other is po 1282 which is fuel pump relay iv replased the relay with a now good one and ran a hot wire to pump and it works I need to get truck smoged frustrated in calif
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Kewliam
October 29, 2011.



Have you checked for spark?


Caradiodoc
Oct 30, 2011.
Yes it has spark on the pick I sent 56 and 30 are hot key on 87 is ground when I ground 85 87 goes hot and truck runs


Tiny
Kewliam
Oct 31, 2011.
Rats. With the tests you've done, it does appear the computer is not grounding the fuel pump relay. It needs pulses from the crankshaft position sensor and the camshaft position sensor to do that. If one of those signals is missing, there won't be spark.

Listen for the hum of the pump for one second after turning on the ignition switch. If you hear that, the fuel pump relay is good and the computer has control of it. If you don't hear it, suspect the computer, but before you condemn it, ground the relay coil right at the computer plugs. If the relay clicks on, that will confirm that wire between the relay and computer is okay. Next, there should be four ground wires, two listed as "signal" grounds and two as "power" grounds. The best test for them is a voltage measurement while the relay is bypassed and the engine is running. If you find more than a couple of tenths of a volt, check that wire for a corroded connection to the body.


Caradiodoc
Oct 31, 2011.
Tested all hots to computer and grounds, I grounded pin 19 at(c3) and relay worked pin 2 and pin 22 on(c1) both are hot im going to dive in and get the computer and hopping it taks care of the po1282 ill let u now what happends and thank you donation will be comming


Tiny
Kewliam
Oct 31, 2011.
Caradiodoc, it was the computer I ended up using a 341ae insted of a 341ac becouse thats the only used one I could find for under a 100 dollers the last letter is a upgrade! Thanks for your time I was a master teck for firestone 6 years ago un"till a chain snaped on the old alingment rack and the safty latches gave out and landed on me it broke my back owell. I dont chang parts untill its fixed, like alot of those (book smart) master tecks lol ! Like my dady told me, do it right the first time or youll have to do it again have a nice day whhoooya


Tiny
Kewliam
Nov 8, 2011.
Sad to hear it was the 'puter but happy it's solved. Chrysler had extremely little computer trouble back then. I'm still on my original one in my '88 Grand Caravan daily driver with 230,000 miles.

Hope your back is better.

I know all about "book smart" too. I taught auto shop for nine years with another instructor who taught straight from the text book. That doesn't help someone be successful on the job.


Caradiodoc
Nov 8, 2011.