6.5 Diesel glow plug, glow plug relay and fuseable link test

How to test the glow plugs, glow plug controller and the fuseable links

[@tulltree]

I'm working on my 93 6.5 replacing these. I discovered burned fusible links and got to wondering how all of this works. I looked in and saw the relay but it was great to look up a video showing all these tests I can do. Thanks for taking the time to make this video, I found it really helpful. Now to see what I need to do to my truck!

[@bluesmanj]

Driver's side was a breeze, took an hour...passenger side took three hours. I found it easier to just remove the inner fender though, without doing that i don't know how i would have gotten the two gp's closest to the firewall. Thanks again for your help with this video! you da man!

[@zhinomortgages]

Thank you for the video. My '99 Burb won't start, WTS still works, but lights don't dim. This video will help me start looking for the culprit.

[@stlouissux9119]

If it were me I would pull the plug wire and test that first because if that's working right you saved the time testing everything else! Good video though, i'm still searching for a 6.5

[@bluesmanj]

@CostcoBulkBuyer I removed the tire then the inner fender (the black one). It was way easier to do that than to struggle getting to the other plugs, especially if you have a cordless drill with a ratchet attachment, it took me all of 10-15 minutes to remove the tire and the fender. I didn't have to remove the manifolds or anything. Once you pull the fender it's real easy to get to everything. Good luck!

[@jimmyerbe768]

I see you are doing the shade tree stuff when its snowing, reminds me of working on my equipment up north, thank god I moved to the south Carolina coast !

[@bowtieboy4273]

Great video! You did an excellent job explaining that that thanks!

[@johndeereman2009]

Thank you

[@bluesmanj]

Looks like the passenger side of my 99 suburban is still tough to get to...maybe pull the inner fender? Thanks for the video, you made trouble shooting the glow plugs a piece of cake!

[@bmccarty1]

Great video Johndeereman. I'll subscribe and watch all your 6.5L content. Thanks.

[@johndeereman2009]

@bluesmanj No problem glad this video helped you out

[@09Youba]

Thank you for the videos. My 6.5 turbo glow plug light will not come on. It will start on the second crank. I guess this would be a good place to start. I checked the fuse and it is ok. Any suggestions would be appreciated.

[@DsrtRatnSnow]

hey jdeere. Thanks for the video. I arced the wire on the right side of the controller. I lost my glow plugs in the process. The glow plug fuse was intact. I'l going to check the fusable links.

[@denisfrancoeur5590]

Hello, Thanks for the video and your time! my 6.5 1999 glow plug light on dash come on a second and truck won't start! Did test the relay and power is to it but when key on no power to the other relay side. did install a new relay controler nothing has changed. I start my truck using a wire to bring power to other side of relay holding 15 sec. and does start every time. I think glow plugs and harness are find. Can you help me please? Denis

[@Mrtlmlkthomp]

If the second (passenger) side post on the relay does not light up when ignition is on that for sure mean I have a bad relay? I ask because it is a new relay and if so I was sold a defective one. It's a 1998 2500 silverado.

[@OldSkoolF]

If Glow Plug light and Service Engine Soon Lights don't turn on when the Key is turned... The ECM Ground is Corroded or Broke.. It is a 16GA. Black W/White stripe. In Harness along back of Firewall. Usually connects to rear Intake Ground Bolt.

[@johndeereman2009]

@HDZipp No problem any more questions let me know

[@johndeereman2009]

@joemaya27 Im not shure what the problem could be

[@leoanoya4186]

Hi John, thanks for the video. I have a 78 VW Rabbit diesel. I have a problem, when I turn the switch On the glow plug yellow ligth from the dash board keeps On, and one relay kees cliking, and the battery get too weaks.

[@johndeereman2009]

@cdelviscio Im not shure why, they may be in a different location, possibly further from the relay that what mine are

[@dreamofmules1343]

Hi! Great videos! Quick question for anyone who knows? When i test the fuseable link side of things with the test light only stays on for a second? The one on my dash stays on for its first cycle a few seconds or so i guess? So the test light, why does it only blink? Is this correct, are my plugs getting hot? With out removing them to see? Why does the test light not stay on as long as dash light? Any help much appreciated!

[@thomasmurphy1562]

Thank you good information

[@bbplayer546]

@johndeereman2009 I’m having an issue on my 96 6.5. I’m getting power to the relay but not out of it, I just put a new relay in too. Not sure where else to look

[@lifeastruggle8600]

Having the same problem

[@MudRFunR]

Very informative, thanks for sharing!

[@itsnegl3ct341]

Just bought a 96 with dual 5" stacks on cold start in like 20 degree weather im getting a small cloud noticed the one glow plug passenger side wasnt even plugged in so im going to dig in there this weekend anything else i should look at? Has a bunch of leaks the engine is good just all 25 year old hoses and such so master and brake booster getting replaced aswell new to these 6.5s

[@johndeereman2009]

Check the harmonic balancer and harmonic balancer pulley. The rubber insert that goes between the inner and outer part of both balancers will sometime separate or look like it is squeezing out. And look to see if the rubber has a lot of cracks in it, or dry rot. A bad harmonic balancer and or harmonic balancer pulley can lead to crank shaft failure. hope this helps

[@DsrtRatnSnow]

checked power at the 10 amp fuse. No power, fuse is not even blown. I'm wondering what I fried.

[@official_g6106]

I didn’t get power after terminal when I cycle the key I think it took a shit

[@Fazsha123]

Also, the 10amp glow plug fuse.... is not seeing 12vdc, on either side... where does this fuse get it's power from? Thanks.

[@selbyhall3145]

I have an 84 K5 that was originally a 6.2 but the previous owner had a 6.5 HMMWV dropped in her. I've been running the truck on 85% WMO mixed with 15% RUG. In the past year I've melted 3 sets of glow plugs. I was told by a few mechanics that it could be because the WMO burns so hot. Also was told it could be because my timing is off. Any thoughts.

[@Fazsha123]

Hoping this question might help others (john, GREAT vid, thanks). I'm seeing 12vdc on the glow plug side of my relay (good); BUT, I'm not seeing 12vdc (test light), when I probe the glow plug feed wires... not before the white inline fuse, nor after... and I'm not seeing 12vdc at the actual glow plug connector... what am I missing? Thanks!

[@joemaya27]

my mitsubishi L300 van has problem on its heater indicator... (standby time at night about 7pm. the next morning, around 6:30am) When i turn on the ignition switch my heater indicator color is red, and then 4-5minutes and that's the time the heater indicator turns into color green. Before my heater indicator turn green after 20-30seconds. Glow plug is ok, heater relay also ok... Please help, if you know about this kind of problem, tnx..

[@jalalnasir85]

I'm getting a negative on both sides of glow plug relay.. Why.? How to fix

[@CostcoBulkBuyer]

@bluesmanj question, i saw one of your post on the 6.5l glow plug test, how did you manage to get the 2 glow plugs on the passengerside?when you mean by removing the fender, as in the big one? i manage to move the rubber plastic cover pop on. so far i have replaced 6 glow plugs, the other 2 hard one i didnt, was i was lazy and its cold outside here in anchorage alaska. did you have to move the exaust manifold on passenger side by anychance?

[@willhudson5703]

On my 6.5 diesel turbo It won’t start up in anything below 70°

[@CherokeeArchetype]

Hey JDM big fan! Question, I have only two terminals and a harness on my relay, right terminal has 1 live wire (cycled or not), left has 2 wires with no power (cycled or not) what do you think?

[@CherokeeArchetype]

98 chev 3500 4x4 6.5l

[@CherokeeArchetype]

I replaced relay and can here actuation from it click as before, same power situation, even while clicking I get no power from left terminal but in the fuse box I get power from slot designated glow plug 10a on ignition warm up it flashes in and out for a few seconds in between. I noticed the new relay had two small silver threads sticking up at the bottom housing as if it could be ground but came with no nuts

[@jimanus07]

right there in the fuse box..... whats that little black fuse there on the bottom right. that went out my gmc savanna 3500 6.5.... help!

[@captnhook236]

Diodes

[@dominicpersuitte4194]

Who is here from streetspeed717?

[@ericflores804]

Comment King I was looking for someone else

[@mlentretienpaysagerdeneige7970]

what if their is no power on the other side where the terminal where the fusable link is ?

[@maddmark1]

Yea I have the same problem. I'm not getting power to the glow plugs. I also don't have power to the fuse that says glow plugs. Fuse is good. I also don't get a wait to start and check engine light when you turn on the switch. What can it be??

[@henryminecraftgamer1280]

I har a question about glowplugs how can i talk to u

[@johndeereman2009]

Thank you

[@shawndinterman2219]

when you turn the key to activate the "WAIT TO START LIGHT" does the Lift Pump come on during that process? If so does it stay on all the time? or does it turn itself off after a few moments? Im trying to figure out if I need/want a LP pump relay harness or do I already have one? when I turn the key over it says wait to start and you hear a pumping type sound, then after a few moments it shuts off. is that normal for it shut itself of

[@johndeereman2009]

Yes the lift pump will shut off after a few moments, then once the engine is running the pump will continue to run

[@shawndinterman2219]

thank you for replying I really appreciate you doing that...whats your thought on a LP relay harness from leroy diesel? worth the money or not?

[@johndeereman2009]

I don't know I have never bought anything from Leroy diesel. I did not know he even sold products for the 6.5 diesels. Most of what I buy for my diesel comes from Heath diesel or in the past SS diesel supply

[@craigl8922]

At WTS, the lift pump should activate in 1996+, but it should not shut off; you should start it immediately after WTS goes out (glow plug dwell). However, if you have a LeRoy Diesel WTS harness, it might shut off at a certain pressure, but I do not think so.

[@joemaya27]

@johndeereman2009 hmmm, ok sir...

[@jimmyerbe768]

Great video but your camera work made me diizzy the sick

[@lifeastruggle8600]

Yup

[@willhudson5703]

I plugged it up for an hour and it was 70° and it still wouldn’t start

[@johndeereman2009]

@HDZipp No problem any more questions let me know