s10 electrical problem with horn

[boss429]

ok, i have a 2001 s10 ext cab pickup 4x4. i bought the truck from an auction it was in an accident airbags deployed and all. well i finally got the truck back together now and pluged all the wires in. well problems is my horn wants to go off every night by its self and i can't find out why i know its got to be a short somewhere but can't find it. i don't have alarm system on it that was my first guess any ideas would help a-lot. i also have a problem with my gauges i beleive it has to do with my horn short not sure though if you trun the truck off and watch the temp and oil gauge they both move up when the trucks off, i can unplug the battery and the same thing still happens i am really lost and don't feel like taking it to a shop and paying upwards of 40 an hour if i don;t have to cuase i am betting it just something really easy.

[MT-2500]

Check horn relay.
Was the air bags fixed and or clock spring replaced.

If horn relay is good unplug the wire to steering column horn sir/bag horn button and see if it still does it.

40$ hr is cheap labor rate for a dealer .
The main thing is good work.
Some or over a 100$ hr.

On the gauges it may be normal for them to go up with key odd.
Do they work good with engine running?
Go down to your local car/truck lot and try one there and see what the gauges do with key off.

[boss429]

yes the airbags where replaced although airbag light is still on, clock spring was not replaced shop said that the clock spring was still good as for the relay i am not sure how to check that i know if i push on the horn button the horn works. but then i also know that just because the horn works doesn't always mean the relay is working properly.how should i test the relay... and yes the gauges all work properly when the truck runs, just when you turn the truck off the gauges move and sometime you can just barely see the letter p for park and the trip light just slightly when the truck is off. but that only happens like once a week that you can see those to lights.. and other then the horn going off at night my only concern is the airbag light. i know if i put another bcm in the truck the light is off but then the truck won't start so that doesn't help much. any ideas would be great thanks

[MT-2500]

Originally Posted by boss429

yes the airbags where replaced although airbag light is still on, clock spring was not replaced shop said that the clock spring was still good as for the relay i am not sure how to check that i know if i push on the horn button the horn works. but then i also know that just because the horn works doesn't always mean the relay is working properly.how should i test the relay... and yes the gauges all work properly when the truck runs, just when you turn the truck off the gauges move and sometime you can just barely see the letter p for park and the trip light just slightly when the truck is off. but that only happens like once a week that you can see those to lights.. and other then the horn going off at night my only concern is the airbag light. i know if i put another bcm in the truck the light is off but then the truck won't start so that doesn't help much. any ideas would be great thanks

If the air bag light is on your air bag is not going to work.
Pull sir code and find out where the problem is.
If a clock spring is bad it could be the horn problem to.
Post back code or codes.

The horn relay can be repaced or swaped with a known good one .
If relay does not fix it disconnect the horn button wiring to steering column.
If horn still goes off you have a wiring problem someplace besides steering column.
If the disconnect fixes the going off you have a clock spring or air bag problem or a shorted wire in steering column.
Good Luck
MT

[boss429]

hi i checked the relay and its working from what i can tell i have no problem in the steering colum and the airbags just needed the light reset so that wasn't my issue any other ideas as to where i may have a wiring short would sure help, cuase this horn problem is getting to be really annoying unpluging and plugging it back in when i go to drive its getting old really fast ..so i hope i can find out what the problem is soon

[MT-2500]

Originally Posted by boss429

hi i checked the relay and its working from what i can tell i have no problem in the steering colum and the airbags just needed the light reset so that wasn't my issue any other ideas as to where i may have a wiring short would sure help, cuase this horn problem is getting to be really annoying unpluging and plugging it back in when i go to drive its getting old really fast ..so i hope i can find out what the problem is soon

Reread post 4
And go threw the repair procedure as outlined there.
And post back what you find.
As stated in post no 4.
The horn relay can be repaced or swaped with a known good one .
If relay does not fix it disconnect the horn button wiring to steering column.
If horn still goes off you have a wiring problem someplace besides steering column.
If the disconnect fixes the going off you have a clock spring or air bag problem or a shorted wire in steering column.
Good Luck
MT
__________________

[boss429]

i already did all that and the horn still went off. thats why i asked where to look for a wiring short elsewhere the steering colum is fine no shorts and horn still went off with wires unpluged relay is brand new and i know it works the clock spring is working properly . so now i need to start looking for a short somewhere else i just don't know where to start..

[MT-2500]

If you have unpluged the horn wire at the steering column and it still goes off then remove the horn relay and see if it still goes off.

Only three things can honk the horn.
A grounded horn button wire between horn button and relay or bad/shorted relay.
Or a direct short between the horn feed wire and a 12 volt wire.

Go over things that happened in the accident and look for shorted wiring.
And make sure there is not a aftermarket alarm someplace.

[boss429]

i now have a new issue i got the horn fixed it was a broken horn wire under the relay . but now my new on is i replaced my fuel pump last night and now i have a random multiple cylinder misfire which i never had before any ideas 4.3 4x4

[MT-2500]

What is the fuel pressure reading?

[boss429]

fuel preasure is right what if should be i can't remember right now what it was but i know it was right at what is should be. any ideas

[MT-2500]

The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold and fuel pressure testing guide line.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.

MT

[boss429]

with the key on not running the pump is reading 70psi . with the truck running the pump ranges between 70 and 80 psi and i still have a missfire p0300 code still coming up put new plugs in checked the wire cleaned up my cap which was new as of last month and yet i still have the p0300 code please help its starting to make me mad. i don't get how changing a fuel pump with batterie unpluged should cause my truck to form a new problem it never had before.. also i have a brand new fuel filter thanks

[MT-2500]

You have to much fuel pressure.
Is you fuel pressure tester gauge good?
To much or to low fuel pressure can cause a misfire.
Even a few lbs off can mess it up.

If you have to much pressure check fuel pressure regulator or a restricted return line.

[boss429]

well im guessing its the regulator but how to i check to see if thats bad without pulling the intake manifold off...