1HD-T Voltage Converter Relay Question (2 Viewers)

[marcjs]

My HDJ81 began having starting issues over the weekend, whereupon first attempt to crank I would simply hear is the relays engage, but no starter cranking. Upon second attempt it would consistently crank and fire. I knew this would be short-lived, so I began troubleshooting. I'm glad I did because in the process of troubleshooting, that behavior changed, and now she no longer cranks/fires.

I checked continuity of the voltage converter relay (VCR hereon in). When applying voltage to eg (solenoid), it has continuity between 1- and E... although resistance increases from what it is unenergized, it nonetheless has continuity energized. I take this to mean the contacts for the normally closed side of the relay are hanging or welded.

The relay (28420-17011) is unavailable Stateside, so I placed an order through an EBAY vendor from NYC. Having made the buy-it-now the vendor now informs me it will take 7-10 working days to arrive. Given that, he is likely sourcing from Japan or UAE.

Has anyone succeeded in servicing one of those relays? It would require drilling out the four spot-rivets in the bottom of the case. Given that I am otherwise dead in the water, I have little to use to try opening the can and seeing whether it can be temporarily made functional by freeing and cleaning the seized contact.

 

[Squash]

Check fusible links! They might look good, but they are old. May light up a tester, but can it supply sufficient current?
Verify that the fusible link from the battery is up to snuff by trying a length of fused wire out to the starter relay while waiting for your parts. I took this even further by adding a momentary switch which allows you to spin the engine with or without the key but uses only 12volts. Love this mod because the 24v olt system kicks the engine over in winter way better than 12volt and I have a selection of 12 and 24 volt Toyota's.

 

[marcjs]

@Squash, I plan on checking all of them tonight. I opened up the VCR (PITA!) and cleaned the contacts with a business card (apparently abrasives are a no-go for silver contacts). A burnishing blade would have been the better option, but I do not own one.

There were some obvious hot-spots, but nothing was welded-shut, so I suspect maybe the reading I received may have been due to me simply disconnecting battery negatives, which could have left another path to close the loop when the relay was energized, and I checked resistance from 1- to E. In any event upon reassembling, testing on a bench, and reinstalling I got the same result. Like I said, I may have learned a lesson the hard way.

Tonight I'll check power to starter solenoid when turning the key. That will also serve to test the fusible link. Not fun as I just finished an epic job of resealing my injection pump - only to enjoy it for a week before this .

More to come...

 

[Squash]

Depends on what you are using to test with.
Do not depend on a test light.

 

[marcjs]

Just to close this post out - turned out to be my starter.

As simple as one could expect pulling the starter out could be, it turned out to be more difficult due to lack of access. The starter is attached using two fasteners through the mounting flange: a M12 x1.25 hex bolt accessible from underneath and an M12 x1.25 nut affixed to a stud off the bell-housing on top.

Although the lower bolt is readily accessible for removal/replacement, the upper nut is a PITA! Several hoses/electrical connectors, as well as a hard fuel-line obstruct access. Visibility is also a challenge. I often wrench on European cars (Bimmers/VWs/Volvos/Alfas), which leave me with the impression that their engineers HATE mechanics. Very seldom do I feel that way about Toyota designers. This was one of those exceptions.

Nonetheless, it's all back together and cranks so faster than it used to! I love this truck!!!

 

[MUDZLLA]

Just to close this post out - turned out to be my starter.

As simple as one could expect pulling the starter out could be, it turned out to be more difficult due to lack of access. The starter is attached using two fasteners through the mounting flange: a M12 x1.25 hex bolt accessible from underneath and an M12 x1.25 nut affixed to a stud off the bell-housing on top.

Although the lower bolt is readily accessible for removal/replacement, the upper nut is a PITA! Several hoses/electrical connectors, as well as a hard fuel-line obstruct access. Visibility is also a challenge. I often wrench on European cars (Bimmers/VWs/Volvos/Alfas), which leave me with the impression that their engineers HATE mechanics. Very seldom do I feel that way about Toyota designers. This was one of those exceptions.

Nonetheless, it's all back together and cranks so faster than it used to! I love this truck!!!

Yeah those heavy starters are a bitch to get out and harder to get back in. Couldn't imagine a 12V in there. Need just the right extension and a bit of luck.

The FSM has a bench test for the 12/24V starter solenoid IIRC to check if thats the problem. I recall taking one apart once but ended up having to find a new used one at the end of the day.