Engine/Transmission (1994 - 1998) Starting Problem, Electric

[Matt42]

I have a similar, maybe the same, starting problem, with a twist. Here goes.
Truck:
=1996 49 state 5 speed 4x4.
=Daily driver?
no.
=Last driven?
90 days ago. (Was working out of state, etc. )
=Miles on truck:
75K, 10 miles/day stop & go, many starts.
=Weather?
Dry, warm, 80 to 115F
=Symptom?
Wait to start, hear click, no start. Multiple repeats: no click, no start.
=Swapping relays made no difference.
=Do lights dim when trying to start?
No
=Batteries?
Dekka AGM, new, OK.
=Voltage at starter, big wire:
12 V
=voltage at solenoid--brown wire:
12 V when ignition turned on
=voltage at solenoid when ignition turned off:
12 v after trying to start (yes, I checked twice!)
=Pulled starter relay and voltage at solenoid went to zero.
Did not recheck after putting relay back in. Should have. (insert dope slap here. )
=Starter solenoid contacts replaced in 05 or 06 with Larry B's original, not the supers.
=So I removed the starter
Works OK with no load.
Had load tested this evening at Checker. Failed three tries.

If it weren't for the very odd condition of power to the brown wire staying on with the ignition switch out of the start position, I'd just chalk this up to an old starter that's had hard city use. But this is the most vexing starter problem I've ever seen. Any ideas? I am flummoxed and it ain't pretty. Could that odd condition be due to welded solenoid contacts?

Thanks y'all and it's nice to be back.

 

[mweiman]

It sounds like your starter contacts are welding together or possibly the relay is sticking. It probably is not a bad idea to replace the relay anyways if it has seen a lot of use. I am not really familiar with rebuilding starters but I would have to say there is a problem with it for sure if it is getting good power and not turning over.

 

[Matt42]

Makes sense. I neglected to mention that I swapped out a different relay (several use the same part number) with no change in result. I am going to go back and edit to that effect.

I have a replacement starter on order. If that is the problem, I will rebuild the original one when I have spare time. If not, I have a spare starter. The trick is to find a starter that isn't made in China.

 

[Extreme1]

Cancel your starter order!



Here's your fix. The contacts are sticking together and the slight current is enough to hold the relay(s) closed. It's an easy fix and something most trucks on here have had or will have done.



The next problem is a fried fuel solenoid starting coil. Get that from Larry and install it right away too.

 

[Matt42]

Cancel your starter order!

Here's your fix. The contacts are sticking together and the slight current is enough to hold the relay(s) closed. It's an easy fix and something most trucks on here have had or will have done.

The next problem is a fried fuel solenoid starting coil. Get that from Larry and install it right away too.

Wouldn't it have started? And then the starter just stayed engaged causing all sorts of other trouble? Or is my memory fried also? (Possible--I won't rule it out. )

I've had a Larry B's Solenoid-Saver diode installed for quite some time. As I was doing the checking, the diode wire cama apart at the crimp connection, so I removed it before I made the voltmeter tests, which I neglected to mention in my first post. What jogged my memory was clicking on your link to Larry's ad, which shows the new diodes to be potted to prevent the problem I had. Back-current would have been about 30 seconds during the test. I hope.

I'll check the contacts in the morning.

 

[Matt42]

Contacts are fine

I just finished checking the contacts. They are in very good shape, just as Larry B said they'd be. I replaced them in 2004 according to my records. There is only light wear, it's very even, some black dust and no evidence of burning or welding.



Now I'm very confused. What would be causing the problem? Bad ignition switch, bad rest-of-the-starter? :{



Anybody have experience with new manufacture Remy brand starters? That's what's on order, though it'll be rejected if made in China.

 

[hcole]

Try this. Put the trans in neutral and then take a jumper wire and momentarily jump the bat + to the brown wire on starter. If it turns over starter is OK, and the trouble has to be in wiring before starter. When checking, make sure that you have a load on the brown wire if you check the wire when its disconnected as it takes VERY little current flow to make a digital meter read 12 volts.

 

[mweiman]

it sounds to me like the rest of the starter is bad. One other thought, are you sure you are getting a good ground? Maybe try running a set of jumper cables from the battery ground to a starter bolt or cleaning your cable to be sure. Do you have a reputable shop that rebuilds starters/alternators in your area?

 

[Dave M]

If its not a bad starter, I'd start by removing the starter relay in PDC and with clutch depressed and ignition to start verify you have 12v at pin 86 of the starter relay and then verify the 12v is removed with ignition in run or off. If it stays on then the problem is in the ignition switch and/or clutch pedal switch. In other words this start relay is somehow staying energized and this test is trying to see what inputs and outputs of the starter relay are to find out why.



Verify you aways should have 12v at pin 30 with ign in run or start or off (12v is supplied from fuse 2 in PDC labelled Ign run 40 amp). Pin 87 is the output of the starter relay and is a BRN wire that goes two places. The BRN wire goes to the starter solenoid at starter (BRN wire) and also to the fuel shutdown relay BRN wire and pin 85 of the fuel shutdown relay. This is the wire that the Larry B diode is placed. Is it in there properly? You might remove it to eliminate a problem with it and reconnect the brn wire without it temporarily.



To eliminate a possible interference of the fuel shutdown relay with the starter solenoid (since they both are the same BRN wire tied to the output of the starter relay in the PDC) try unplugging the fuel shutdown relay and then crank the starter. The truck won't start but the starter should crank.



Post those results.

 

[Matt42]

What I ended up doing was jumping across the starter relay socket contacts as suggested by Missouri Mule in Common Sense Tips.



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It started. So I worked back up the system and found a loose connection to the starter line in the steering column. I can't explain where the voltage at the brown wire to the starter came from.



My wife returned to the Checker. They gave her no trouble about canceling the special order and refunding money, especially when she pointed out that the starter that their starter checker said was bad was really just fine.



Sorry to rile everyone up. But that jumper idea is a great diagnostic tool.

 

[Dave M]

Glad you got it fixed. The starter relay is a good place to diagnose starter trouble. It looks like your jumper is connected from the starter relay pin 30 (on left in pic) which should always be 12v from the PDC fuse labelled Ign Run to pin the 87 which is the output of the relay on the BRN wire to the starter solenoid.



You probably had 0 volts on pin 86 of the relay which is 12v from the ignition switch when in Start position thru the Clutch switch.



The jumper is a good way to check circuit. I'll remember that.