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s10 electrical problem with horn


boss429
10-26-2007, 11:51 PM
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
10-27-2007, 11:08 AM
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
10-27-2007, 11:38 AM
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
10-27-2007, 01:09 PM
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
10-27-2007, 09:55 PM
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
10-28-2007, 09:13 AM
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 :grinyes:
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
10-28-2007, 02:33 PM
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
10-28-2007, 05:22 PM
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
10-29-2007, 05:16 PM
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
10-29-2007, 05:29 PM
What is the fuel pressure reading?

boss429
10-29-2007, 10:11 PM
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
10-30-2007, 08:45 AM
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
10-31-2007, 10:24 PM
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
11-01-2007, 08:25 AM
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
11-01-2007, 01:33 PM
well im guessing its the regulator but how to i check to see if thats bad without pulling the intake manifold off...

MT-2500
11-01-2007, 04:25 PM
well im guessing its the regulator but how to i check to see if thats bad without pulling the intake manifold off...

You might also want check direct fuel pump pressure by blocking a return line or checking direct at fuel filter.
If you have good full fuel pump pressure around 95 lbs.
Then pull return line at intake and hook in a jumper line to fuel tank or a good container.

A while back someone had a rust restriction in his return line at at the tank.
His pressure would start out good and keep raising.

Does the running on the road fuel pressure hold steady or high all of the time?

What was the problem with old pump?
Did it also have low or high pressure?
Any chance you pinched a return line when it was replaced?

boss429
11-01-2007, 09:38 PM
nothing was wrong with the old pump the old pump had a bad fuel level sensor and when i pulled the pump to replace the level sensor i seen that my fuel pump assembly was bent some so i bought a new on the old one worked great never checked the preasure but had no p0300 code with it didn't pinch any lines and the return line is free and clean of any crap nothing is stoping the flow so its the regulator how do i check to make sure that the regulator is bad thanks

MT-2500
11-02-2007, 09:05 AM
nothing was wrong with the old pump the old pump had a bad fuel level sensor and when i pulled the pump to replace the level sensor i seen that my fuel pump assembly was bent some so i bought a new on the old one worked great never checked the preasure but had no p0300 code with it didn't pinch any lines and the return line is free and clean of any crap nothing is stoping the flow so its the regulator how do i check to make sure that the regulator is bad thanks


As said if the pump has good pressure and the return line is not restricted then the fuel pressure regulator is not regulating pressure right.

boss429
11-05-2007, 12:05 AM
hi i just replaced the fuel preasure regulator today and also made sure all gas lines where free and clear of any crap which there was none in them but my fuel system is still reading the same preasure i still have 80psi when key is on so i am kinda thinking its not a fuel regultor/ cloged line or pump thats my problem sense they have all been checked but today after i changed the fuel regulator the truck started right up ran for about 1 min and 75/80 psi stumbling like normal and when i pushed on the gas its stumbled and then stalled out and will not longer start just cranks i know its got fuel cuase its did run and i still have 80psi and the shrader valve so what else could it be its starting to get annoying now that i just spent a full day and 65$ on a preasure regulator and it wasn't even a bad part. seems like the more work i do the worse the truck gets any help out be very helpful. 2001 s10 4x4 4.3l vin w auto trans

MT-2500
11-05-2007, 08:20 AM
hi i just replaced the fuel preasure regulator today and also made sure all gas lines where free and clear of any crap which there was none in them but my fuel system is still reading the same preasure i still have 80psi when key is on so i am kinda thinking its not a fuel regultor/ cloged line or pump thats my problem sense they have all been checked but today after i changed the fuel regulator the truck started right up ran for about 1 min and 75/80 psi stumbling like normal and when i pushed on the gas its stumbled and then stalled out and will not longer start just cranks i know its got fuel cuase its did run and i still have 80psi and the shrader valve so what else could it be its starting to get annoying now that i just spent a full day and 65$ on a preasure regulator and it wasn't even a bad part. seems like the more work i do the worse the truck gets any help out be very helpful. 2001 s10 4x4 4.3l vin w auto trans


Proper testing will save you throwing parts at it.
If the fuel pressure is going 0ver 66 lbs confirm your gauge is good.
Then remove return line from intake and install a good jumper line to catch return gas in a proper container or reroute to fuel tank.
Fuel regulator controls fuel pressure if your pump is putting out good pressure and the return is not restricted your fuel pressure regulator is not working right.
MT

boss429
11-05-2007, 01:46 PM
ok well i still have high fuel preasure but now thats not my big problem as for my truck not starting i have spark at my coil wire but not coming off my dist any ideas cuase i am kinda lost i always though if the coil had spark so would the distributor.. thanks

MT-2500
11-05-2007, 02:06 PM
ok well i still have high fuel preasure but now thats not my big problem as for my truck not starting i have spark at my coil wire but not coming off my dist any ideas cuase i am kinda lost i always though if the coil had spark so would the distributor.. thanks

80 lbs of fuel pressure is a problem you need to deal with.

On the spark in and no spark out of dist.
Does it have spark on any plug wires?
Is the spark from coil a good hot blue spark?
How far will it jump on a spark tester?

Pull cap and rotor and check for cracks or signs of shorting across or out of cap and rotor.

And make sure the dist shaft is rotating when cranking engine.
A stripped dist gear or roll pin will keep the dist from turning.

boss429
11-05-2007, 02:27 PM
im using a timing light to check the spark so i don't know if the spark if bright or not and no none of the 6 wires have any spark what so ever i will check to make sure it turn the distributor gear in a minute.. if it does turn what next the cap is fine no cracks of burns

boss429
11-05-2007, 02:32 PM
the distributor does turn so what else to check for

MT-2500
11-05-2007, 02:45 PM
the distributor does turn so what else to check for

To check for spark use a spark tester.
Is the coil putting out good hot blue spark and into dist?

boss429
11-05-2007, 03:23 PM
well i will have to go buy a spark tester but in the mean time with the timeing light the coil sparks 5 to 6 times then pause then 5to 6 times again etc

MT-2500
11-05-2007, 05:18 PM
well i will have to go buy a spark tester but in the mean time with the timeing light the coil sparks 5 to 6 times then pause then 5to 6 times again etc

Is the coil wire good?

In place of a spark tester as long as you do not have a pace maker hold one end of wire a 1/4 to 1/2 from engine ground and see if you have good hot blue spark that will bite you and snaps at you.
Good luck
MT

boss429
11-05-2007, 06:48 PM
ok i have good blue spark coming off the coil wire but as soon as you plug it into the distubtor cap i can test all 6 wires and none are getting spark is there a way to short the cap out or something cuase this truck is starting to get very annoying first i have a fuel problem which still is not fixed after a new regulator with the same fuel pump that the truck ran great with when it was bent in the tank. it all started off cuase my gauge was reading wrong so i fix that problem by the new fuel assembly but same pump and then it started the p0300 as soon as i got the new assembly in the tank and started the 80psi fuel preasure so i checked for a clogged line and it was clear so i put new fuel regultor on and that didn't help just made the truck run the same only difference is the started started stumble and stalled and now i have no spark to any plugs so i am starting to thing this is a never ending problem thats just getting worse and i put new parts on... any ideas would be really great before i just buy another truck

MT-2500
11-05-2007, 06:58 PM
If the coil is firing good and the coil wire is good and the dist is turning good then go for a new AC delco dist cap and rotor.
Good Luck
MT

boss429
11-05-2007, 07:10 PM
how would the cap and rotor all of a sudden go bad inless thats why my truck has been acting up but i don;t know anyways how would the cap go bad to the piont where no spark at all comes out of it ???

boss429
11-05-2007, 09:35 PM
ok i came to the conculsion i don't think its the cap and rotor i think its my pickup coil has went bad cuase i don't think a cap and rotor would just go bad when the truck is running but the pickup coil is electric and i think that is more of a safer bet for me to try..

MT-2500
11-07-2007, 08:32 AM
ok i came to the conculsion i don't think its the cap and rotor i think its my pickup coil has went bad cuase i don't think a cap and rotor would just go bad when the truck is running but the pickup coil is electric and i think that is more of a safer bet for me to try..


Proper testing will give you the answer.
Good luck
MT

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