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Discussion Starter #1
Hi, first post here. Hoping it’s in the right place.
I recently bought a 1996 F250 Powerstroke. I’ve been having some starting issues after the first week of owning, initially the starter wouldn’t crank, so I replaced the starter unit as it still had the original with 370,000km on it.
This seems to solve the cranking issue but I found that I had to cycle the glow plugs 5-6 times before starting which was no biggie. When I had the time I was going to look into the glow plugs and relay. This worked fine for 2 weeks until last night I turned the key and got the check engine light with no crank or even solenoid engagement. Relay 2 in the power distribution board is chattering as long as the key is in the ‘run’ position. I switched the relay out to no effect, also checked fuses 20+22 which are both fine.
Not 100% sure on where to go from there, this is my first old ford. Any ideas?
TIA
 

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Most of the time a chattering relay is a weak set of batteries.

The glow plugs draw up to 200 amps and that puts quite a load on the batteries

Sent from my SM-J737V using Tapatalk
 

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Welcome! Normally when that relay starts "chattering", it's a low voltage issue. Have both batteries checked independent from one another. Check all battery cable and end (all ends) for tightness and corrosion. Only time iI witnessed this in person was when my brother-in-law's 95 had a battery internally short. On glowplugs, the WTS light is only a reminder to wait. Even when it turns off you can wait longer for the plugs to keep heating (they will stay on for up to 2 minutes). Cycling doesn't really do much. You can also plug in the block heater for a couple of hours prior to starting to see if that helps. The cord is usually stuffed under the driver's side battery area.

To check the glowplug relay (GPR), measure the voltage drop across the GPR's large terminals. While the GPR is active (up to 1.5 to 2 minutes after the key is turned to Wait-to-Start) put your meter leads on the large terminals (one lead on one large terminal and the other lead on the other large terminal). This measures how much voltage is being "lost" across the relay. A reading of 0.3V or more indicates a bad relay. Also, check the relay’s control wires (smaller wires) disconnected from the relay for battery voltage at the Red/Light Green striped wire and ground at the Purple/Orange striped wire (check both when the key is turned to Wait-to-Start). If the relay is bad, most folks will recommend a White-Rodgers 586-902 as a better replacement.

Cheers!
 

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I am with Patrick and Bugman. Check your batteries, disconnected them from one another and the truck then test and check all connections too. (Steve83 will probably give you the proper procedure soon).
What is your temperature outside? If your glow plug relay looks old then it is probably due for the White Rogers upgrade, I did both my trucks last spring and it made a world of difference I should have done it years earlier. Test yours first it still could be fine though. If the above checks out could be glow plugs or wiring. These two are still not that bad if you know how to turn a wrench.
 

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Don't JUST check the batteries (using the proper high-frequency tester) - you should also take a really-close look at the battery TERMINALS. Click these & read the captions:

(phone app link)


(phone app link)


(phone app link)


(phone app link)


It's also worth checking EVERY ring terminal on the battery & alternator cables, AND where the alternator case touches its mounting bracket on the engine.

(phone app link)


(phone app link)


You'd be amazed how much better an old alternator & batteries will perform when they have clean connections to & from all their high-current loads.
 

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Discussion Starter #6
Thank you all for your help. You’ve confirmed what I had suspected, I swapped the batteries out and cleaned up terminals which could never hurt as it’s coming into winter here in the Canadian Rockies. It seems to have solved the issue, once I get some more time on my hands I’ll check the glow plugs and relay and chase for any drains.
cheers
 
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